Historic Variations in Arctic Sea Ice – Part Two

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Map of the Arctic Ice Cap Source: http://www.athropolis.com/map2.htm

Guest essay by Tony brown

Foreword
Note; Last year an edited version of this article appeared at Climate Etc. This new version contains numerous additional references, graphics, quotes, more historic detail and updates.

http://judithcurry.com/2013/04/10/historic-variations-in-arctic-sea-ice-part-ii-1920-1950/

‘Historic variations in Arctic Ice’ is a series of articles that attempts to determine the arctic warming events through the Holocene which commenced some 11000 years ago. (See Graphic ‘after Dansgaard et al’ below. Part 1 covered the warm period from approx. 1816 to 1860.

After Dansgaard et al. Note; a graphic such as this can only be a broad approximation and will not reflect nuances of climate.)

 

This paper- Part 2–examines the period of warming 1920-1940 in detail with a decade long overlap.

Part 3 will examine the evidence for other episodes of warming through the Holocene.

During the course of compiling this article numerous relevant papers and studies were referenced, personal research conducted at the Scott Polar Institute archives and library in Cambridge, the Met Office archives and library in Exeter, and communications made with such organisations as the University of Fairbanks in Alaska, NSIDC, and arctic climate scientists.

We are primarily concerned with identifying that these warming episodes occurred, not what caused them, Readers are encouraged to follow the links/references to understand the context of the brief extracts used.

Summary of Results

  • Modern Arctic ice reconstruction data bases show a high level of ice in the period 1920 to 1940 that declined rapidly during the period of satellite observation from 1979 with a notable acceleration over the last decade. However, the historical record demonstrates that the modern record substantially overstates the ice extent of the earlier period.
  • We find that estimates of sea ice of the era often excluded Russian sources and that estimates from other areas appear to have shortcomings.
  • Much of the arctic was unexplored and the certainties with which climatological methods were used to estimate the sea ice boundaries appear unsound.
  • Arctic warming during the period was very widespread, reached considerable levels, was particularly pronounced in some regions and at certain times of the year and lasted for several decades..
  • Evidence is presented of substantial arctic glacial melt.
  • Records of thinning arctic ice evident over many decades is presented
  • Reports of warm water ingress and the part the transpolar drift stream played in removing ice are noted.
  • The controversy surrounding Dr Christy’s remarks that ‘the Arctic had indeed warmed (in recent years), but there was also anecdotal and other evidence suggesting similar melts from 1938-43 and on other occasions.” is explored.
  • Arctic warming appears to be part of a much more general warming of the world during the period which does not seem to be fully represented in the global temperatures data.
  • An estimate of the likely amounts of sea ice present during the era is made in the paper. ..

In a future article it is hoped to put pre-1950 conditions into context to those of the modern day, as the difficulty of integrating and interpreting two very different types of material derived from unrelated measuring systems –observational versus satellite – can be readily seen and are discussed in the conclusions in Section Six.

SECTIONS:

  • Section One The 1920-1940 Arctic-A period of controversy
  • Section Two The History of Sea ice data
  • Section Three Modern climatology studies
  • Section Four A look back from the 1960’s and 70’s
  • Section Five Data from Contemporary sources-1920-1940
  • Section Six Observations and comments

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Section One The 1920-1940 Arctic-A period of controversy


The first scientific expedition to the Arctic by William Scoresby in 1818 was facilitated by the Royal Society to examine reports of extraordinary warming in the region, first noticed by whalers around 1800. It was referenced in Part One of this series;

http://noconsensus.wordpress.com/2009/06/16/historic-variation-in-arctic-ice-tony-b/

Whilst ad hoc sea ice data has been collected for centuries- such as 11th century Icelandic records- accurate pan arctic ice observations started in the 1970’s and is still an evolving branch of climate science.

So how do we know that sea ice levels have declined since the post 1979 satellite era?

To determine this, some context to official figures covering the 1920-1940 arctic melting is necessary.

This statement was made by the IPCC in AR4 of 2007;

‘Average Arctic temperatures increased at almost twice the global average rate in the past 100 years. Arctic temperatures have high decadal variability, and a warm period was also observed from 1925 to 1945’

The arctic ice melt extent noted by the IPCC, was supplemented in an interview by Dr Walt Meier of The National Snow and Ice Data Center in Denver:

 

“Analysis of the temperatures does not support a cyclic explanation for the recent warming. The warming during the 1920s and 1930s was more regional in nature and focused on the Atlantic side of the Arctic (though there was warming in some other regions as well) and was most pronounced during winter. In contrast, the current warming as observed is amplified over almost the entire Arctic and is seen in all seasons. Another thing that is clear is that, the warming during the 1920s and 1930s was limited to the Arctic and lower latitude temperatures were not unusually warm.”

 

The period from around 1920 to 1940 has become controversial due to the substantial variance between the ‘official’ view of modest and geographically limited arctic (and global) warmth, and the view held by others, unconvinced that current arctic (and global) warming is unique.

The controversy was noted in Neven’s ‘Arctic sea ice’ blog where an excerpt from the Sunday Times was highlighted;

http://neven1.typepad.com/blog/2012/08/similar-melts-from-1938-43.html

In this, Neven queried the accuracy of a quote made by Professor John Christy director of the Earth System Science Centre at the University of Alabama in Huntsville. In this excerpt Dr Christy said that “the Arctic had indeed warmed (in recent years), but there was also anecdotal and other evidence suggesting similar melts from 1938-43 and on other occasions.”

The rationale behind Neven doubting Dr Christy’s statement makes his short article-and the comments- worth reading. Neven referenced a graphic by Kinnard et al (reproduced below) which helps to put other graphics into a broader context. (Note: Neven responded in the ‘comments’ section to the original article at Climate Etc.)

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http://wattsupwiththat.files.wordpress.com/2014/08/f7fb3-6a0133f03a1e37970b017744530698970d-pi.jpg

An equally interesting but longer article on the period was carried here;

http://www.skepticalscience.com/record-arctic-sea-ice-melt-to-levels-unseen-in-millennia.html

It states;

“Christy has become very reliable for arguing that anything and everything related to climate change probably just boils down to natural variability, as he recently told US Congress was the case with regards to the frequency of extreme weather events, contrary to the body of peer-reviewed scientific literature.

As we will see in this post, Christy once again misrepresented the body of scientific literature with regards to Arctic sea ice extent (1938-1943) in his efforts to paint the Arctic sea ice death spiral as nothing out of the ordinary.”

Bearing in mind the controversy surrounding the subject, it is useful to outline how science determined the extent of current and historic ice levels, with particular reference to the period under review.

 

Section Two The History of Sea ice data


There are many meetings and areas of research that are of particular significance to recent arctic ice science. The following are reasonably representative in noting key papers, players, and uncertainties that persist to this day.

This workshop in 1978 represents the knowledge of the time.

‘Workshop on Mapping and Archiving of Data on Snow Cover and Sea Ice Limits-Boulder, Colorado 2-3 November 1978)” (Published in May 1979)

http://nsidc.org/pubs/documents/gd/GD-5_web.pdf

Of special interest are; 1) “Background and objectives’ and 2) ‘Recommendations’ as this puts contemporary knowledge into perspective. These two comments are intriguing;

‘The spatial and temporal characteristics of global snow cover and sea ice are major components of the ‘climate system’ and its variability on time scales of weeks to decades. The need to incorporate such cyrospheric data into climate models for diagnostic and predictive studies is now widely recognised, but there is a significant lack of reliable, high quality, long-term data sets. The objective of a contract funded by NOAA/EDIS to the WDC-A for Glaciology (snow and ice)is to begin to remedy this deficiency , firstly by developing an inventory of present data sets.’

And;

“There is a wide need for ‘historical’ series of sea ice and snow cover charts. Operational series should be carefully revised, incorporating data from all sources … It is important that estimated and interpolated values be flagged in data sets derived from chart series. Final digitised products should be cross-checked and their consistency documented.”

Amongst the many papers of interest in the referenced pdf are;

‘Mapping and archiving of Canadian sea ice data’ by Markham p.37

Walsh’s early work on ‘Digitisation of Northern Hemispheric sea ice data’ on p.99

Kelly, “An Arctic sea ice data set 1901-1956,” p. 101-106:

“Inadequacies in archived sea ice data” William Dehn page 107

The papers covering satellite data are of considerable historical interest as reliable pre 1979 sea ice data was very limited, with much based on Kelly’s information for 1901 to 1956

The next meeting to highlight is from 1997;

Report on Study of the Arctic Change Workshop November 10-12, 1997 University of Washington Seattle, Washington

The most interesting item for our purposes is ‘Arctic warming during 1920-1940; A review of old Russian publications’ by Pisarev (A paper we return to later)

http://mclean.ch/climate/Arctic_1920_40.htm

This was followed by;

Proceedings of the Workshop on SEA-ICE CHARTS OF THE ARCTIC

(Seattle, WA, USA, 5-7 August 1998)

Sponsored by the US National Ice Center July 1999

http://ipo.npolar.no/reports/archive/iapo_inf_03.pdf

This extract is from the ‘Executive summary;’

“The Workshop for Sea-ice Charts of the Arctic was convened…because of the perception that information contained in ice charts was under-utilised by the scientific community. Participants…distinguished ice charts of the historical era (1200 through 1930 A.D.) when information was primarily limited to ice extent, from ice charts of the modern era 1930 A.D. to present) when information about the ice pack interior is more generally available. Several reports illustrated the quantity and quality of the ice chart information, and suggested the data are adequate to support scientific investigations of the historical era (e.g., the Historical Ice Chart Archive Project) and from the modern era (e.g., Global Digital Sea-ice Data Bank).”

By 1995 the IPCC second assessment provided a focal point for climate science. References are made to them in the extended abstracts from the workshop; This from “On The Use of Historical Sea-ice Charts in Assessments of Century-Scale Climate Variations” (page 1)

John E. Walsh1, Konstantin Vinnikov2 and William L. Chapman1

“However, the sea-ice record presented by the IPCC extends back only to the early 1970s. Conclusions about sea-ice trends prior to the 1970s must be based on historical sea-ice charts. Thus the adequacy of these charts for meaningful detection of sea-ice trends is a key issue in the context of century-scale climate trend assessment, especially since the greenhouse scenarios of global climate models show substantial decreases of sea ice coverage over the next several decades. In this paper, we discuss the feasibility of using historical sea-ice charts to assess century-scale sea-ice trends in the context of the projections of a global climate model.”

 

And from “About Clarity and Resolution of Ice Charts” Igor Appel

“The main goal of the present meeting is to review and assess ice chart information to the scientific community.…. Research spans a wide range of temporal and spatial scales. Even consideration of climate change can be limited by small area. Therefore it is desirable to create ice charts with fine resolution. It is clear that resolution does not signify accuracy. There were a lot of discussions at the meeting about improving spatial resolution of ice charts; 10 km and finer resolution have been mentioned. But there are numerous examples demonstrating that ice charts created in different ice centers for the same area and day differ very significantly. Difference in location of ice edge can reach hundreds of kilometers.”

 

This apparent lack of consistency of sea ice charts makes this next document highly relevant as some issues mentioned in the first few workshops remain on-going and the gathering and interpretation of historic sea ice data is incomplete.

Cambridge UK meeting of the International ice charting working group October 17-21, 2011 British Antarctic Survey, Cambridge, U.K.

The ‘Back to 1870’ project described here will re-examine existing material and input new data in a manner that enables modelling through a digitised gridded Pan Arctic data base.

http://nsidc.org/noaa/iicwg/presentations/IICWG_2011/Fetterer_Back_to_1870_Plans_for_a_Gridded_Sea_Ice_Product.pdf

“The 30-year timeframe of gridded pan-Arctic sea ice data sets limits their utility in reanalysis and climate diagnostic applications. The one available pan-Arctic database extending back to the 1800s is the Hadley Centre’s HadISST, in which the gridded sea ice is essentially climatological prior to the 1950s, especially in the winter half of the year. Our project will synthesize various historical datasets that have recently become available for inclusion in a pan-Arctic sea ice dataset spanning 1870-2010.”

Various people working on the project will by now be familiar, whilst others will be referenced as this article develops;

“In Alaska (Univ. Alaska Fairbanks) John Walsh, Adrienne Tivy, Student help

In Boulder (National Snow and Ice Data Center) Florence Fetterer, Vivian Underhill

In Illinois (Univ. Illinois, Urbana-Champaign) Bill Chapman,

Also linked to this work indirectly are Kevin Wood, Univ of Washington; Hajo Eiken, UAF; Andy Mahoney, UAF; and Allaina Wallace, NSIDC.”

The International Ice Charting working group ‘Back to 1870’ project will be invaluable as there is a clear need to improve our understanding of past, present, and future ice extent. (Note; See update at end of this article)

Estimates of Arctic ice extent, density, volume etc- has been carried out informally and formally for many years by whalers, explorers, the Hudson Bay co, indigenous peoples and many others. The Cambridge group notes the various data bases used to construct ice conditions prior to and during the period in question as follows;

  • AARI gridded data, 1930-1970s [1990s]
  • Danish Meteorological Institute yearbooks, 1870s-1960s
  • ACSYS sea ice databank (North Atlantic ice edges, 1750-1966
  • National Research Council of Canada (B. Hill), Newfoundland ice extent, 1810-2000+
  • Alaskan ship reports (whaling and others) K. Wood and Bockstoce/Mahoney/Eicken, 1850-early 1900s
  • Plus HadISST-1 and coordination with new HadISST-2

Other influential reconstructions include those from Kelly, Chapman and Walsh, B Hill and S Jones (shown in the Cambridge 2011 document) and the Kinnard et al reconstruction referenced earlier.

The Danish Meteorological Institute yearbooks mentioned are online from 1893-1956 and from which this explanatory quote is taken;

http://nsidc.org/data/docs/noaa/g02203-dmi/

“The positions of direct observations are marked on each chart with red dots (Figure 1). Each chart shows the mapmakers’ inferred ice edge as well as the type of ice present, for example large ice fields or new ice, in certain locations. As a reference for today’s user, these descriptors have been converted into approximate percent-coverage values by V. Underhill and F. Fetterer at NSIDC, based on a combination of historical references. See Table 1 and Table 2 for these values.

Coverage is considerably better over Greenland, Iceland, and Spitzbergen than for the rest of the Arctic, and direct observations over the Western Arctic are particularly sparse over the entire period of record. From 1946 to 1956, the ice edge in this region solely reflects annual climatology; the DMI probably did not have access to any data in this region because of the Cold War. “

This from the 1978 conference previously referenced;

“ Sea ice charts have been published (by DMI) from 1900 to 1956 for the Arctic seas, and from 1957 to 1964 for the Greenland waters (Fabricius 1961 DMI 1964) .The earlier data are from ship reports. Aerial reconoissance has been used since 1959.”

The official material available seems to demonstrate limited arctic melt during the period so Neven appears to be right in asserting that Dr Christy is incorrect in his claims. However, the Northern hemisphere sea ice data 1870- 2011 has this cautionary note

http://arctic.atmos.uiuc.edu/SEAICE/

“Please note that large portions of the pre-1953, and almost all of the pre-1900 data is either climatology (weather conditions averaged over a period of time) or interpolated data and the user is cautioned to use this data with care (see “Expert user guidance”, below). “ (Chapman)

So, it appears that historic sea ice data, mostly compiled since the 1970’s) is not definitive. Why should this be?

Russian information of the era for example, as well as other historical information, may not have been utilised, perhaps because it is considered ‘anecdotal’ or maybe had not come to light when much of the sea ice data was being constructed. Consequently, with the benefit of hindsight, existing official data is possibly not as robust as it might appear.

Before exploring this theme further in Section Three, presentation of official data will provide better overall context. Figure 1.2 from the following link shows arctic land station temperature anomalies 1900-2011 from NOAA.

http://www.arctic.noaa.gov/reportcard/temperature_clouds.html

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Fig. 1.2. Arctic-wide annual average surface air temperature (SAT) anomalies for the period 1900-2011 relative to the 1981-2010 mean value, based on land stations north of 60°N. Data are from the CRUTEM3v dataset at www.cru.uea.ac.uk/cru/data/temperature/. Note: this curve includes neither marine observations nor 2012 data, as the year was incomplete at the time of writing.

Most notable is the peak in the late 1990’s to around the levels of the 1940’s –then a rise to some 1 degrees C above the 40’s, despite apparent plateauing of global land temperatures, thereby representing considerable arctic amplification.

Another version with some useful explanation can be seen here from NASA;

http://earthobservatory.nasa.gov/Features/ArcticIce/arctic_ice3.php

The arctic temperature anomaly graphic show a rise through the 1920’s and a considerable peak in the 40’s, a slight decline and plateau and in 2002 a rather lower modern temperature (Note; the item dates from around 2002)

 

Section Three Modern climatology studies


Section Three examines the output of scientists from the modern period examining the 1920-1940 data. Section Four examines that era’s material compiled during that active period of climatology of the 1960’s and 70’s, whilst Section Five reviews the output from the contemporary scientists of the day, and examines other information from that era.

Kelly from CRU (then the University of East Anglia) was present at the 1978 meeting referenced earlier and many subsequent papers were derived from his study of sea ice 1901-1950. CRU remains active in arctic research with Professor Phil Jones illustrating temperatures in Greenland during 1784-2004 (published 2006) It usefully complements the NOAA and NASA (arctic wide) temperatures referenced. His graphic showing coastal instrumental records comes from Page 10 figure 10 of the following link.

http://www.cru.uea.ac.uk/cru/data/greenland/vintheretal2006.pdf

This link provides the composite data used; (http://www.cru.uea.ac.uk/cru/data/greenland/swgreenlandave.dat

“The warmest year in the extended Greenland temperature record is 1941, while the 1930s and 1940s are the warmest decades. Two distinct cold periods, following the 1809 (‘‘unidentified’’) volcanic eruption and the eruption of Tambora in 1815 make the 1810s the coldest decade on record.”

The Figure 10 composite raises some intriguing issues. The warmest two decades in the Arctic record- the 1930’s and 40’s- did not apparently cause as much melting as the current shorter-but becoming warmer- Arctic warm period commencing around 2000. That data can be seen in the NOAA and NASA graphs referenced, and also in the link below, where data was brought up to 2011.

http://www.skepticalscience.com/Greenland_ice_sheet_summer_temperatures_highest_in_172_years.html

Note the different parameters used here of ‘Greenland ice sheet summer surface air temperatures: 1840-2011’ rather than the coastal temperatures used in the CRU study, but whilst not like for like the general trends can be seen.

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http://data.giss.nasa.gov/gistemp/graphs_v3/

Whilst the 2000’s show a plateauing of global temperatures, the apparently unprecedented modern arctic ice melt points to considerable arctic amplification at temperatures there that, until the last decade, were similar to, or below, the earlier period in the arctic.

Reference was made earlier about the lack of Russian data possibly impacting on the historic charts. It was noted in this 2008 document;

‘Observed sea ice extent in the Russian Arctic, 1933–2006’

by Mahoney, Barry, Smolyanitsky and Fetterer (two of whom are involved in the ‘Back to 1870 group.’)

http://seaice.alaska.edu/gi/publications/mahoney/Mahoney_2008_JGR_20thC_RSI.pdf

“We present a time series of sea ice extent in the Russian Arctic based on observational sea ice charts compiled by the Arctic and Antarctic Research Institute (AARI). These charts are perhaps the oldest operational sea ice data in existence and show that sea ice extent in the Russian Arctic has generally decreased since the beginning of the chart series in 1933. This retreat has not been continuous, however.” (see article for context)

And;

“During the second International Polar Year in 1932, the Directorate of the Northern Sea Route was created in Russia to ‘‘develop the Northern Sea Route as a regularly operating transport system’’ [Barr, 1991, p. 27]. Shortly afterward, in 1933, the Arctic and Antarctic Research Institute (AARI) began to regularly produce sea ice charts of the Russian Arctic seas based on aerial, ship, and coastal reconnaissance. The AARI ice charts, as we will refer to them, therefore represent the longest operational ice chart record in existence”

Historic note: See figure 1; Generally speaking, from 1933 onwards there were four prime methods of ice observation, land, air, ship and official polar meteorological stations. Aviation, for much of the period examined, was in limited use especially in remoter areas which encompassed much of the region.

‘From the mid 1930s, aviation was used to collect ice information and from the mid 1940s became the main source of sea-ice information in the Siberian Arctic (JOHANNESSEN et al 2004)’

Historic note; The opening of a Northern sea route (also called the Northeast passage) has implications for understanding ice dynamics of the time, becoming an important supply route during World War 2 although until the period in question was not useable in any practical manner, as noted here;

“In 1932, a Soviet expedition led by Professor Otto Yulievich Schmidt was the first to sail all the way from Arkhangelsk to the Bering Strait in the same summer without wintering en route. After a couple more trial runs, in 1933 and 1934, the Northern Sea Route was officially defined and open and commercial exploitation began in 1935. The next year, part of the Baltic Fleet made the passage to the Pacific where armed conflict with Japan was looming.”http://en.wikipedia.org/wiki/Northern_Sea_Route

The Alaska edu link continues;

“The earliest chart in the AARI data set is from July 1933. Charts were produced every 10 or every 30 days, depending on time of year. Spatial coverage did not extend far into the central Arctic, and the charts were only produced during the summer months in the early part of the series.”

Other limitations are noted here;

“Because of a lack of sufficient data coverage we only consider the western (Russian) area of the Chukchi Sea. Similarly, the sea ice edge could not be consistently located in the westernmost sector of the Kara Sea, so this is excluded from our analysis.”

“The eastern half of the Chukchi Sea was omitted because of insufficient data coverage. Similarly, the sea ice edge could not be consistently located in the westernmost sector of the Kara Sea. This area is excluded from the analysis”

 

(Note: The area covered is shown in figure 2)

“…. Period A, from the beginning of the record (1933) until the mid-1950s, was a period of declining summer sea ice extent over the whole Russian Arctic, though not consistently in every individual sea. Period A is not evident in the winter and spring months and is not as well defined during the autumn partly because of a lack of sea ice charts at this time of year at the beginning of the record. Period B extended from the mid-1950s to the mid-1980s and was a period of generally increasing or stable summer sea ice extent. For the Russian Arctic as a whole, this constituted a partial recovery of the sea ice lost during period A, though this is not the case in all seas. Periods A and B can also be seen in the MY ice record for the overall Russian Arctic (Figure 7), though as mentioned earlier, MY ice extent in the Barents and Kara seas peaked in the 1960s. Period C began in the mid-1980s and continued to the end of the record. It is characterized by a decrease in total and MY sea ice extent in all seas and seasons. In this regard, period C is markedly different from periods A and B.”

“The sources used to compile the HadISST data set are given by Rayner et al. [2003]. Up to 1978, HadISST used the Northern Hemisphere Walsh fields [Walsh and Chapman, 2001] as its main data source, which in turn relied upon ice charts from a number of different sources to locate the sea ice edge. However, prior to satellite observations, none of these charts provided coverage in the Russian Arctic further east than the Kara Sea [Kelly, 1979; Vinje,2001]. Where no sea ice edge data were available, a baseline climatology was used. Such instances are apparent in Figure 8 where the green data points are constant from year to year in the early part of the record.”

Item 4 of the paper ‘Discussion’ and item 5 ‘Conclusions’ on page 9 are worth reading in full.

This next Russian item usefully focuses on the core warming era and was presented at the Arctic change workshop in Seattle in 1997 as “Arctic Warming” During 1920-40: A Brief Review of Old Russian Publications by Sergey V. Pisarev and was briefly mentioned previously;

http://mclean.ch/climate/Arctic_1920_40.htm

This rich source of information is briefly described in the index;

1. The idea of Arctic Warming during 1920–40 is supported in Russian publications by the following facts:

  • retreating of glaciers, melting of sea islands, and retreat of permafrost
  • decrease of sea ice amounts
  • acceleration of ice drift
  • change of cyclone paths
  • increase of air temperature
  • biological indications of Arctic warmingease of navigation
  • increase in temperature and heat content of Atlantic Waters, entering Arctic Basin.

The two page extract linked above can be read in full. The larger report it comes from is no longer available on the link cited; http://psc.apl.washington.edu/publication/Arctic_Change/arctic.pdf

The following extract from the Pisarev data usefully introduces two prominent scientists of the era, Zubov and Alman, whose work we shall examine in greater detail shortly. (Note; there are various spellings of ‘Alman’ used)

“During the Persey cruise in 1934 Zubov noticed that the glaciers of Jan-Mayen and Spitsbergen were considerably reduced, relative to their sizes adduced in British sailing directions of 1911. Retreat of glaciers was observed also at Spitsbergen, Franz-Joseph Land (Russia), and Novaya Zemlya (Russia). The ice bridges between some of Franz-Joseph islands melted.
Alman explored the glaciers of Spitsbergen in 1934 and came to the conclusion that they were melting. The observations of 1935–1938 showed that Iceland glaciers were melting too.”

The possible lack of historical data from Russia and other areas, or an assumption that ice was present unless contrary reports were received, could clearly impact on estimates of sea ice extent in the period. That there are potential gaps in our knowledge seems to be indicated in this 2004 paper;

The Early Twentieth-Century Warming in the Arctic—A Possible Mechanism

LENNART BENGTSSON

Max Planck Institute for Meteorology, Hamburg, Germany, and Environmental Systems Science Centre, University of Reading,

Reading, United Kingdom

VLADIMIR A. SEMENOV

Max Planck Institute for Meteorology, Hamburg, Germany, and Obukhov Institute of Atmospheric Physics, Moscow, Russia

OLA M. JOHANNESSEN

Nansen Environmental and Remote Sensing Center/Geophysical Institute, University of Bergen, Bergen, Norway

Conclusions;

“The Arctic 1920–40 warming is one of the most puzzling climate anomalies of the twentieth century. Over some 15 yr the Arctic warmed by 1.78C and remained warm for more than a decade. This is a warming in the region comparable in magnitude to what is to be expected as a consequence of anthropogenic climate change in the next several decades. A gradual cooling commenced in the late 1940s bringing the temperature back to much lower values, although not as cold as before the warming started. …this warming was associated with and presumably initiated by a major increase in the westerly to southwesterly wind north of Norway leading to enhanced atmospheric and ocean heat transport from the comparatively warm North Atlantic Current through the passage between northern Norway and Spitsbergen into the Barents Sea….the increased winds were not related to the NAO, which in fact weakened during the 1920s and remained weak for the whole period of the warm Arctic anomaly. …the process behind the warming was most likely reduced sea ice cover, mainly in the Barents Sea. This is not an unexpected finding because of the climatic effect of sea ice in comparison with that of an open sea but is intriguing since previously available sea ice data (Chapman and Walsh 1993) did not indicate a reduced sea ice cover in the 1930s and 1940s. However, as we have shown here recent sea ice datasets [Johannessen et al. (2004) give a detailed presentation] actually showed a retreat in this period.”

http://www.nerc-essc.ac.uk/~olb/PAPERS/len19.pdf

These extracts come from Johanssen et al 2004-;

“The global gridded SAT data set (Jones et al., 1999) used most extensively for studies of climate variability has major gaps in the northern high latitudes, in particular over the ice-covered Arctic Ocean and some surrounding land areas.”

And;

“However, it remains open to debate whether the warming in recent decades is an enhanced greenhouse-warming signal or natural decadal and multidecadal variability (Polyakov and Johnson, 2000; Polyakov et al., 2002), e.g. as possibly expressed by the arctic warming observed in the 1920s and 1930s followed by cooling until the 1960s (e.g. Kelly et al., 1982). The uncertainties are exacerbated by a lack of homogeneous, century-scale instrumental data sets (see Moritz et al., 2002, whose fig. 2a includes no temperature data for the central Arctic) needed to resolve the inherent timescales of variability in the Arctic (Venegas and Mysak” Figure 1a shows the time evolution of the zonally averaged anomalies in annual mean SAT from 30–90◦N. Two characteristic warming events stand out, the first from the mid 1920s to about 1940 and the second starting about 1980 and still ongoing. Here, we show that the early twentieth-century warming was largely confined to north of 60◦N, whereas the latter warming encompasses the whole Earth (Jones et al., 1999) but is none the less significantly enhanced in the Arctic (Fig. 1a).”

“In the Atlantic–European sector (Greenland and Barents seas), the sea-ice extents from 1900 to the late 1950s are known only from spring and summer (April to August). …. An attempt has been made to obtain these missing mean annual data. Towards this end, the actual year-round data on the ice extent from 1959–1988 were used to derive an equation to calculate the annual average ice extent in the region….(enabling) the missing annual ice-extent means from 1900–1958 (to be) calculated. The main problem of any reconstruction is errors inevitable in the procedures of data series reconstruction. This problem can be resolved by comparing the actual and calculated annual ice extent averages…Thus, the methodological error of the reconstruction comprises only one third of the rms deviation of the actual series, indicating a sufficiently high reliability of the reconstruction method used.”
http://www.tellusa.net/coaction/index.php/tellusa/article/viewFile/14418/16180

A report about North Western Russia entitled ‘Long-term climate trends of the Yamalo-Nenets AO, Russia’ from 2010 comments;

http://met.no/Forskning/Publikasjoner/filestore/Ealat_Yamal_climaterep_dvs-1.pdf

“All series show warm periods in the 1940s and 1990s, and a cold period in the 1960s. Salekard (the only station with observations at that time) was cold also around 1900.”

Page 40 summary and conclusions;

“Increasing temperatures from 1900 to the mid-1940s (often referred to as the “early 20th century warming.

2. Decreasing temperatures from the mid-1940s until about the mid-1960s.

3. A “recent warming” from the 1960s to 2003.

For Yamal this is shifted to the period 1965/70s-1990/95s.”

Note; This paper contains much useful meteorological information covering this significant area, including first and last day of snow cover, temperatures etc .

Clearly modern knowledge of the era and interpretation of the increasing amounts of data that has become available enable us to look afresh at the historic sea ice charts compiled in earlier decades.

 

Section Four A look back from the 1960’s and 70’s


The 1960’s and 70’s saw increased scientific attention to climatology with growing access to records and modern instruments, amid concerns we were headed towards another mini ice age. In this section we examine the 1920-1940 period from that mid-century perspective.

P59 of Volume 1 of Jean Groves book ‘The Little Ice Ages’ second edition, noted;

‘that the relationship between (Icelandic) glacier variations and climate change can be traced most closely since 1930 when glacier monitoring began and meteorological measurements were already long established. Very cold decades at the beginning of the twentieth century were followed by strong warming in the 1920’s and an unusually warm period from 1926 to 1946. Within ten years glaciers were in retreat and the whole period from 1930 to 1970 was one of predominant withdrawal. By 1962 all the monitored glaciers had retreated from their 1930 positions.”

Additional scientific information comes from the 1971 book ’Times of Feast, Times of Famine-A History of Climate since the year 1000’ by Dr Emmanuel le Roy Ladurie-a renowned French historian- page 82 onwards, which here references information on the various recent waves of warming;

“The most spectacular amelioration is that of arctic or sub arctic regions, the areas at the extreme limit of Nordic colonization from Greenland to Spitzbergen . In the 1930’s Scherlag diagnosed a winter amelioration November-March of plus 5 degrees C at jakobshavn (Greenland) comparing the periods 1883-1892 and 1923-1932. At Spitsbergen the winter increase reached the phenomenal height of 8 to 9 deg C in the decade 1930 as compared with the normal for 1912-1926.”

It continues;

‘the tendency toward amelioration in the present century in the USSR, varying greatly in degree from the Ukraine to Siberia, was observed just before the last war and by Rubinstein in 1956 (with) mainly the winter months affected. The tendency is more pronounced in northern areas like the Barents sea, the shores of the Arctic ocean and the estuaries of the Ob and Yenisey rivers. Mitchells curves (showing temperature anomalies from 100 stations, one of the precursors to Giss) (demonstrate) there is indeed a world amelioration particularly in winter. It affects principally the Arctic and (secondly) the cold and temperate zones of the Northern Hemisphere including the US, Europe and Siberia. Thirdly it affects the tropics and finally in a much less perceptible way the temperate zones of the Southern Hemisphere. The only areas unaffected by the annual amelioration between 1900 and 1940 are North eastern Canada, a large part of south America, most of the SW quarter of Africa and certain regions of central Asia and Pakistan and of the Indian ocean SE Asia and Australia.’

So the warming of the arctic (and apparently also the Antarctic) was not confined to the polar regions but were –with some exceptions-a considerable worldwide phenomenon. Steinbeck’s grapes of wrath dust bowl years seem to confirm this, as land temperatures in some parts of the world reached record temperatures (for the time) as can be seen in this graph.

Fig.A[1]

http://data.giss.nasa.gov/gistemp/graphs_v3/

Page 122 from this 1977 document returns us to arctic- rather than global- observations.

Hunt and Naske, 1977: A BASELINE STUDY OF HISTORIC ICE CONDITIONS IN THE BEAUFORT SEA, CHUKCHI SEA, AND BERING STRAIT
http://www.arlis.org/docs/vol1/OCSEAP2/PhysicalScience/8516713/FP%20v01.pdf#page=122

It gives interesting insights into how data was collected by whalers, traders and govt. skippers and how each exercised their own degree of caution when approaching pack ice and the leads that may lie beyond. Whilst trips may be regular they were often following the same route so consequently observers may have had a limited perspective.

“Plotting their tracks is an exercise in frustration for anyone seeking a pattern in ice movements because patrol vessels steamed from point to point, doubling their track when necessary, avoiding the ice, of course, but otherwise disregarding it. One factor is common to all three types of Arctic cruises from which data has been drawn: the ice was viewed as a potential obstacle, an impediment to navigation. It was not a seasonal physical feature subjected to long ranged scientific curiosity. There were no standards

by which its particular qualities might be described; comparisons were not drawn from season to season; information was never collected or exchanged. In fact, the ice observer was happiest when he had no reason to mention ice conditions.”

And

“ Since the Department of the Interior has operated ships annually since the 1920… the logs of several Bureau of Indian Affairs ships were eagerly sought… it was disappointing to learn that ice observations were not systematically recorded. The paucity of data cannot be attributed to negligence of reporting standards of an earlier age, as it shown by a second case. The logs of the Foss Tug Co. for recent years of barge voyages to the Arctic are sprucely kept and generously accessible, yet the printed form used by navigators has not provided for ice observations. This situation can be understood, of course. Captains of both types of vessels were never indifferent to the ice, and they guided their ships in response to the closest scrutiny of the ice. Yet, except in the general sense, history was not made in documented form.”

 

Reading the extensive information and asides, the arctic ice researcher might surmise that any records -prior to the satellite era-should be discounted, as the inconsistency of ice data collection methods and unlikelihood of collecting data from leads that may lay beyond pack ice, confirms that comparing the past to the present mixes apples and oranges.

Page 12 of Hubert Lamb’s ‘Climate History and the Modern World’ (originally published 1982 using material collated during the previous decade) notes

‘…from around the beginning of the century up to 1940 a substantial climate change was in progress, average temperatures were rising, most of all in the arctic where the sea ice was receding…the almost four and a half decades of near immunity to very cold winters ended abruptly with Europe’s notably severe war winters in 1940, 41 and 42 and another in 1947.’

Page 259 comments

‘…warming was rapid from about 1920 to 1940 …it was during the second and third decades of the (20th) century that the climatic warming became noticeable to everybody, places near the arctic fringe such as Iceland, Spitsbergen and even Toronto experienced warming that was from twice to five times as great… the average total areas of the arctic sea ice seems to have declined by about between 10 and 20% ….when account is also taken of the changes in the atmospheric circulation and hence in the distribution of rainfall and its variability as well, it is hardly too much to say that the twentieth century climate regime from 1920 to 1960 changed the world.’ Page 261 ‘… the frequency of snow and ice decreased generally and the retreat of the glaciers from about 1925 became rapid.’

In the 1979 book ‘Earth’s Climate Past and Future’ M I Budyko of the State hydrological institute in Leningrad remarks

‘the greatest climatic change within the period of instrumental observations started at the end of the 19th century. It was marked by a gradual rise in air temperatures at all latitudes in the northern hemisphere throughout the year. This warming was especially pronounced at high latitudes and during the cold seasons. The warming intensified in the 1910’s and reached its peak in the 1930’swhen the mean air temperature in the Northern Hemisphere was 0.6c higher that at the end of the 19th century. In the 1940s the warming trend changed to a cooling trend which continued until recently. ‘..In the NH the air temperature rise was accompanied by a contraction of polar ice, a retreat of the permafrost boundary to higher latitudes, a northward shift of the forest and tundra boundary and other changes in natural conditions.’

Section Five Data from Contemporary sources-1920-1940


The comments from the IPCC , Walt Meier and blogs such as Neven, together with data from Walsh and Chapman, Kennard, Hadley and others, seem to indicate a modest intermittent often .localised arctic warming, through the 1920 to 40’s. However, the data they base this on appears to be fragmented, and a different viewpoint can be construed from the work of other modern and mid twentieth century researchers as already referenced. However the most telling glimpses into the past comes from those living during the period so here we examine contemporary records for tangible evidence of arctic warming, discern the period it covers and put it in context with areas outside the arctic described as ‘not unusually warm.’

Continuing the theme of conditions in the Russian sector not being fully covered in official sea ice data- comments should be prefaced that due to World War Two, then the ‘Cold war,’ together with the remoteness of much of the area, international cooperation at the time, and for a period afterwards, was often limited as regards the Russian arctic.

However, prior to this difficult period, and even during it, research still went on and much data was produced which, over the course of time, seems to have taken a back seat.

Arctic researcher Hans Ahlmann noted in 1952 that;

“The extent of drift ice in Arctic waters has also diminished considerably in the last decades. According to information received in the U.S.S.R. in 1945, the area of drift ice in the Russian sector of the Arctic was reduced by no less than 1,000,000 square kilometers between 1924 and 1944.”

This reference by Ahlmann and others concerning the rapidly warming arctic can be picked up on the occasion of a lecture he gave in 1952 as the principal address at the meeting of the Seventeenth International Geographical Congress in Washington, D. C.

http://archive.org/stream/glaciervariation032833mbp/glaciervariation032833mbp_djvu.txt

It gives an intriguing glimpse of the science at the time, highlighting the warming that was of intense interest to many researchers. Several relevant extracts are given below;

“The thickness of the ice forming annually in the North Polar Sea has diminished from an average of 365 centimeters at the time of Nansen’s Fram expedition of 1893-96 to 218 centimeters during the drift of the Russian icebreaker Sedov in 1937-40. The extent of drift ice in Arctic waters has also diminished considerably in the last decades.”

“ The shipping season in West Spitsbergen has lengthened from three months at the beginning of this century to about seven months at the beginning of the 1940s.”

“ The Northern Sea Route, the North-East Passage, could never have been put into regular usage if the ice conditions in recent years had been as difficult as they were during the first decades of this century.”

“The same influences that have affected the drift ice have affected the animal life of the North Polar Sea. Various kinds of fish, especially cod, have migrated northwards. Now for the first time cod is available to many Greenland Eskimos who previously had to rely on seal for food.”

In a (1947) speech…the Danish Prime Minister said:

“In the last generation changes that have had a decisive influence on all social life have occurred in Greenland. …These changes are primarily due to two circumstances. Firstly, the Greenland climate has changed, and with it Greenland’s natural and economic prospects…”

“…herring catches off the north coast of Iceland have greatly diminished in the last seven years, possibly because of changes in the sea currents connected with the present climatic fluctuation. Herring has become an open sea fishery; its 1952 season was extended to November instead of ending as usual in August.”

“…the International Council for the Exploration of the Sea adopt(ed) the following resolution at its meeting in Denmark in 1948: “Having considered a number of lectures on climatic fluctuations, the Council recommends that these important and far reaching problems ought to be more closely investigated, and that these investigations might be adequately supported by the Governments in the different countries”

Historic note;

Dr. Ahlmann was Professor of Geography at the University of Stockholm, and from 1948 to 1951 served as President of the Commission on Snow and Ice of the International Association of Hydrology (I. U. G. G.).”

He forged particularly good links with Russian arctic scientists during a difficult period of international scientific cooperation (especially American), as noted here;

“…in 1934 Ahlmann was invited to lecture at the Arctic Research Institute on his Svalbard expeditions in 1931 and 1934. Ahlmann returned to the Soviet Union several more times, deepening his respect for Russian arctic research especially during visits in 1958 and 1960 as president of the International Union of Geographical Sciences.” http://ipy-osc.no/abstract/380008

This next site gathers some thirty articles and science reports in chronological order concerning the warming that covered a wide area of the world in the period 1900 1949.

http://www.climate4you.com/ClimateAndHistory%201900-1949.htm

Probably the best known and most widely quoted item is this from the Monthly Weather review of Oct 1922. (Edited for space reasons.)

http://docs.lib.noaa.gov/rescue/mwr/050/mwr-050-11-0589a.pdf

http://trove.nla.gov.au/ndp/del/article/77891667?searchTerm=arctic%20melt&searchLimits=

1923 CAUSES OF CHANGE OF CLIMATE.

‘The Arctic seems to be warming up, states George Nicolas Ifft American consul at Bergen, Norway. “ …. fishermen, seal hunters, and explores who sail the seas about Spitsbergen and the eastern Arctic, all point to a radical change in climatic conditions, and hitherto unheard-of high temperatures……

In August, 1922, the Norwegian Department of Commerce sent an expedition to Spitsbergen and Bear Island under Dr. Adolf Hoel, lecturer on geology at the University of Christiania. The oceanographic observations (reported that) Ice conditions were exceptional. In fact, so little ice has never before been noted. The expedition all but established a record, sailing as far north as 81o29′ in ice-free water. This is the farthest north ever reached with modern oceanographic apparatus…..

In connection with Dr. Hoel’s report…note the unusually warm summer in Arctic Norway and observations of Capt. Martin Ingebrigtsen, who sailed the eastern Arctic for 54 years past. He first noted warmer conditions in 1918, since that time it has steadily gotten warmer, to-day the Arctic of that region is not recognizable as the same region of 1868 to 1917.

Many old landmarks are so changed as to be unrecognisable. Where formerly great masses of ice were found, there are now often moraines, accumulations of earth and stones. At many points where glaciers formerly extended far into the sea they have entirely disappeared.

The change in temperature, says Captain Ingebrigtsen, has also brought about great change in the flora and fauna of the Arctic. This summer he sought for white fish in Spitsbergen waters (where) formerly great shoals were found. This year he saw none, although he visited all the old fishing grounds.

There were few seal in Spitzbergen waters , the catch being far under average. This did not surprise the captain. He pointed out that formerly the waters about Spitzbergen held an even summer temperature of about 3o Celsius; this year recorded temperatures up to 15o, and last winter the ocean did not freeze over even on the north coast of Spitsbergen.”

We can reinforce observations that determine the conditions around 1900 and 1940 with this Russian report from that latter year;

http://trove.nla.gov.au/ndp/del/article/62428921?searchTerm=ice%20free%20arctic&searchLimits=exactPhrase%7C%7C%7CanyWords%7C%7C%7CnotWords%7C%7C%7Cl-textSearchScope=*ignore*%7C*ignore*%7C%7C%7Cfromdd%7C%7C%7Cfrommm%7C%7C%7Cfromyyyy%7C%7C%7Ctodd%7C%7C%7Ctomm%7C%7C%7Ctoyyyy%7C%7C%7Cl-word=*ignore*%7C*ignore*%7C%7C%7Csortby

“Is it getting warmer at the North Pole? Soundings and meteorological tests taken by the Soviet explorers who returned this week to Murmansk, Russia’s sole ice-free Arctic port, concluded that near Polar temperatures are on average six degrees(C) higher than registered by Nansen 40 years ago. Ice measurements were on average only 6½ feet against from 9¼ to 13 feet. The return of the Soviet icebreaker Sedoff (note variations in spelling) brought to a close a Polar expedition, involuntarily undertaken which led to important discoveries. For 2½ years she had drifted while trapped in Polar ice. Fifteen men volunteered to stay on board until relief came. In the drift to the north-west these men passed nearer to the North Pole than any other ship. Their highest latitude was 86 degrees 56min North. They discovered by soundings a near Polar sea pocket, 17,260 feet deep.”

Here we can identify the warming extending to around 1952 with again a useful reference to 1900;

http://trove.nla.gov.au/ndp/del/article/42734540?searchTerm=glaciers%20melting&searchLimits=#pstart3099914

“Dr. William S. Carlson, an Arctic expert, said to-night that the Polar icecaps were melting at an astonishing and unexplained rate and were threatening to swamp seaports by raising the ocean levels….it would take hundreds of years for the melting to have much effect, but the rate in the last half century had been exceedingly rapid.

The glaciers of Norway and Alaska are only half the size they were 50 years age. The temperature around Spitsbergen has so modified that the sailing time has lengthened from three to eight months of the year.”

Historical foot note;

William S. Carlson, for whom the University of Delaware’s International Polar Year public events are named, president of UD from 1946 to 1950, was an accomplished polar explorer and scientist. http://www.udel.edu/research/polar/carlson.html

This 1939 report confirms the observed warming was considered widespread, and that the warming that caused this retreating ice could be dated to some 100 to 200 years prior to 1939.

http://trove.nla.gov.au/ndp/del/article/17557868?searchTerm=iceland%20melting&searchLimits=

“One of the riddles which is puzzling geologists all over the world is the continuous retreat of the ice glaciers. Does this phenomenon indicate that the sun is getting hotter … or is it dependent upon comparatively unimportant changes in the earth’s atmosphere?

…these were discussed by Professor R. Speight, formerly professor of geology at Canterbury College, Christchurch, New Zealand in his presidential address to the …Science Congress to-day.

The steady retreat of the glaciers in New Zealand …had been observed during the last 70 years. Photographs taken in 1896 and 1935 showed several glaciers had retreated distances varying from 100 yards to half a mile in 40 years.

The phenomenon, however, was world-wide. Equally impressive records were obtainable from Switzerland, Scandinavia, Iceland and the United States. In Alaska glaciers had been retreating from 100 to 200 years, the average rate of recession being about 50 feet a year. The Antarctic ice- sheet also showed signs of recent retreat.

Professor Speight said, ” (no) region of the world (shows) present signs of an advance. This is quite apart from the general retreat since the pleistocene age and may be merely a pacing phase. Its precise significance can only be determined by continued observation.”

This knowledge that some glaciers had been retreating for some hundreds of years had been expounded by Gordon Manley at various times.

http://trove.nla.gov.au/ndp/del/article/42667524?searchTerm=south%20pole%20ice%20meltingsearchLimits=

 “The earth is getting warmer. The oceans are getting deeper. The glaciers are getting smaller. Even the fish are changing their way of life. All this and more is going on because of a vast, unaccountable, century-by-century change, in climate (according to) Britain’s distinguished geographer, Professor Gordon Manley. Since about 1850 there have been hard and soft winters (he said) but the general tendency has been toward higher average temperatures. It means little at the North Pole, or in Central Europe or America. But there are certain “fringe areas,” on the meteorological edges between hot and cold weather, where the effects even now are spectacular.”

Historical note:

Gordon Manley was a renowned English climatologist who assembled the (CET) series of monthly mean temperatures stretching back to 1659. He hypothesised that (some) glaciers had been in stasis or retreating since around 1750.

http://en.wikipedia.org/wiki/Gordon_Manley

The references concerning the long established retreat of the glaciers-and the specific reference to Alaska- can be put into its context and given a useful time frame here:

“Glacier Bay was first surveyed in detail in 1794 by a team from the H.M.S. Discovery, captained by George Vancouver. At the time the survey produced showed a mere indentation in the shoreline. That massive glacier was more than 4,000 feet thick in places, up to 20 miles wide, and extended more than 100 miles to the St. Elias mountain range. By 1879, however, naturalist John Muir discovered that the ice had retreated more than 30 miles forming an actual bay. By 1916, the Grand Pacific Glacier- the main glacier credited with carving the bay – had melted back 60 miles to the head of what is now Tarr Inlet.” http://www.glacierbay.org/geography.html

Historical note; George Vancouver was a renowned English officer of the British Royal Navy, best known for his 1791-95 expedition, which explored and charted North America’s northwestern Pacific Coast regions, including the coasts of contemporary Alaska. He gave his name to the city of Vancouver.

http://en.wikipedia.org/wiki/George_Vancouver

John Muir was a renowned naturalist and “one of the patron saints of twentieth-century American environmental activity.”

http://en.wikipedia.org/wiki/John_Muir

He founded the Sierra club which to this day remains a leading environmental organisation. In 2008, the Sierra Club endorsed Senator Barack Obama for President.

http://en.wikipedia.org/wiki/Sierra_club

Practical on the ground observations are a useful adjunct to scientific papers, with here noted a comparison of warmer seasons from as far apart as Disko island (Baffin Bay off west coast of Greenland) and Alaska, over as much as a 50 year comparison period.

‘Similar (warming) changes have occurred throughout the Arctic in the natural vegetation… Thus, in 1937, when approaching Disko Island in Bob Bartlett’s schooner Morrisey, I noticed that the flat tops of mountains west of Godhavn that formerly showed no green vegetation above the 2000-foot level were distinctly green from several miles away. During the summer of 1926, which I spent in Alaska, I noticed that on Seward Peninsula the vegetation was fully one month farther advanced that in 1879 when the Swedish botanist Kjellman collected there.”

http://www.thearcticcircle.ca/pdf/Arctic%20Circular%20Volume%202%201949.pdf

Historic note; Bob Bartlett was a familiar figure to our cinema going forefathers during the 1920’s and 30s, his adventures eagerly awaited on British Pathe news reels as Captain on board the vessel Morrisey travelling a warming arctic,

This 1932 article demonstrates that, unlike the modern era, the warming affected both poles whilst highlighting the continued retreat of the glaciers generally and in Greenland and Alaska specifically;

http://trove.nla.gov.au/ndp/del/article/23150667?searchTerm=greenland%20%20melting&searchLimits=

“Some great world change is taking place on the Antarctic Continent. Its glaciers are shrinking. L.A. Bernacchi, who visited the South Polar land 30 years ago, says that the Great Ice Barrier which fronts the continent with a wall of ice for 250 miles has receded at least 30 miles since it was first seen and surveyed. Sir James Ross…on the earliest Antarctic expedition of the nineteenth century, and those who followed him, left clear descriptions of this tremendous ice frontage and its position. It was a cliff 150ft. high and 1000ft. thick. But now it appears to be continuing its century-long process of shrinking; and that process may have been going on for centuries. It might imply, unless it is offset by some increase of ice in another less explored part of the Antarctic, that the climate of the South Pole is changing and becoming warmer. The shrinkage of the Alpine glaciers of Europe is a well-known and carefully measured fact. Professor Buchanan, of Edinburgh, drew attention to it twenty years ago, and showed from old and accurate drawings of (many) that they were retreating rapidly. This led to the continuous measurement of the Swiss glaciers (and) examination of other glaciers of the Northern Hemisphere, Greenland, Alaska, and elsewhere. Prom these measurements many geologists concluded that the northern part of the globe was still recovering from the last of its Ice Ages, of which the more southerly of its glaciers in Europe were a relic. If all the glaciers of the Southern Hemisphere as well as those of the Northern are shrinking, the geologists would have a new problem to examine. It would be whether, instead of areas of cold and ice having shifted on the earth, the whole globe is growing warmer. Even if that could be shown the change might prove to be temporary.”

Historical note on Louis Bernacchi

“Bernacchi studied astronomy, magnetism, meteorology and physics at Melbourne Observatory and made significant contributions to science during his two Antarctic expeditions.”

http://www.antarctica.gov.au/about-antarctica/history/people/louis-bernacchi

By the time of this article in 1937 warming was an accepted fact and attempts were made to quantify its extent and attribute reasons for it.

http://trove.nla.gov.au/ndp/del/article/40174175?searchTerm=%22climate%20change%22&searchLimits=

“The discovery by American seal fishers that …there has been a remarkable increase in the mean temperature of the Arctic, and that in some parts of the Polar basin no ice has been seen less than 9 degrees from the North Pole, agrees with the experience of many Arctic explorers in recent years. Just before the war a party of Russians exploring Nova Zembla (Russia) discovered clear evidence of a branch of the Gulf Stream running north of that Arctic island, between it and Franz Josef Land (Far north of Russia), though all existing charts of that hot-water system place its most northerly extension well to the south of Nova Zembla. (Recent) evidence has accumulated that the Gulf Stream has been diverted, and there is little doubt but that any increase of Arctic temperatures must be caused by warm ocean currents coming up from southerly latitudes.”

1939 heralded World War and the end of much international scientific cooperation for some years, making this next item something of a period piece, highlighting doubts that the warmth should be attributed to the gulf stream. One scientist believed that increased co2 could be responsible for warming-an attribution to this gas that predates most estimates of any likely effect by 30 years, whilst others looked to the sun, so there are intriguing parallels to theories of our current age.

Historical Note; GS Callendar had published his seminal article on co2 in 1938.

http://trove.nla.gov.au/ndp/del/article/69638689?searchTerm=arctic%20thaw&searchLimits=

1939. What is The World Coming To?

“Scientists have confirmed that Arctic regions around Spitzbergen are warming at the rate of approximately one degree in every two years. Since 1910, when observations first started there, the cumulative rise of winter temperature has amounted to nearly 16 degrees. Such a profound change has been at- tended by new and strange phenomena over the whole area surrounding the Polar basin…Polar ice fields are receding gradually northwards… soil which once remained solidly frozen throughout the year now undergoes a partial thaw during the Arctic summers. In the Barents Sea area where, during earlier observations, only small patches became free from ice, large spaces of open water now occur at frequent intervals. Ice-breakers and other vessels which regularly make journeys to the far North are now able to penetrate with comparative ease into regions which could not be reached twenty years ago. There has been a gradual drift northward of several kinds of fish into areas once completely ice covered. The milder conditions have not been confined to areas north of the Russian coast. From parts of Greenland comes evidence of a higher winter temperature, with considerably less snow, than in the early part of the twentieth century. ….Parts of the Polar regions not affected by the warm waters have grown decidedly warmer in the last 20 years, while temperatures have become higher in the far north-east of Siberia and well inland—remote from oceanic effects. In support of the belief that the Atlantic river of warmth cannot be wholly responsible for the widespread rise in temperature there are the trustworthy records by…. the Weather Bureau at Washington, which show that the rise in temperature at places as far apart as Canada and Africa. South America and Asia, Bombay and Santiago (Chile) has been well marked since the middle of last century. It is possible that the world as a whole is becoming warmer. One scientist…theorises that an increase in carbon dioxide (due to the huge amounts of coal being used) may be responsible…while astronomers look to the sun for an explanation. Quite apart from any fluctuations in the sun’s actual output of radiative energy, it is possible that the warmth received from the sun may vary from time to time due to the earth passing through regions of space in which meteoric dust is unevenly distributed.”

This next item from 1943 is a fascinating historic journal, all the more interesting because of its date and the location of many of the observations. It is inscribed;

“I also wish to express my indebtedness to Rear Admiral I. D. Papanin and to V. D. Novikov, who by their care and attention have aided in the completion and publication of this book. Moscow. May, 1943. N. N. Zubov, Naval Captain, Professor, Doctor of Geographical Sciences”

This link leads directly to ‘Arctic Ice’ by N.N.Zubov.

http://www.scribd.com/doc/70835248/90/Section-155-Seasonal-Fluctuations

Page 396 describes 10/10 ice concentration, yet further north very little ice-these extensive leads may not have been taken into account in ice charts where the prime means of observation was by ship. Figure 178, also table 118 on Page 458, concludes that the ice in the Russian sector is hugely variable year by year. In section 162 entitled ‘Warming of the arctic’ Dr Ahlman is mentioned once again.

“Thus, for example, a vessel which attempted to traverse the Northern Sea Route at any cost in August 1936 would have gotten the impression that the route was completely impassable due to ice. On the contrary, a through passage of the Northern Sea Route in the second half of September of that year did not present particular difficulties. “

(Authors note; this illustrates the potential problems in relying on DMI sea ice charts which usually terminated in August)

And

“We may nevertheless point out a number of ship voyages which could hardly have

been accomplished in the preceding cold period. Among these are: our voyage on the sail motor boat Knipos around Franz Joseph Land in 1932, the rounding of Severnaya Zemlya by the icebreaker Sibiryakov in the same year, through passages by ordinary steamships of the whole Northern Sea Route in 1935 (no ice being found on the route), etc….starting with 1930 there was not a single year when it would have been impossible to round Novaya Zemlya from the north even in a ship which was entirely unsuited for navigation in ice. At the same time we know that the icebreaker Yermak in 1901 attempted to round Cape Zhelanla from the west and was unsuccessful, although the Yermak spent almost a month in a struggle with the ice while waiting at the northwest shores of Novaya Zemlya”

And

“We could cite numerous such examples , but the foregoing are sufficient to show that the navigational conditions, at least in seas such as the Greenland, Barents and Kara which have been more completely studied as to ice conditions, have become incomparably easier during the past 10 to 20 years than in previous years. Due to insufficiency of observations, the question of warming of the arctic in its whole broad connotation has been propounded only very recently, namely in connection with preparation for carrying out the Second International Polar Year, when I had to plan the sea expedition routes in advance. Certain phenomena connected with warming of the arctic had been noted earlier. For example, Knipovich was the first to turn his attention to the high temperatures of the Barents Sea in 1921. This warming was then confirmed in 1923 by our voyage on the Perseus to Franz Joseph Land without meeting ice.

Still more remarkable is the fact that the warming of the arctic is not confined to any particular region….the same signs of warming of the atmosphere and hydrosphere are found in the Bering Strait, in the Pacific Ocean as in the western sector of the Soviet Arctic.

A warming of the Antarctic is evidently also going on simultaneously…On the background of general warming of the arctic we are observing warmer years and colder years, but there are not signs as yet that this warming is terminating…

“Sumgin informed me that the southern boundary of permafrost in Siberia is everywhere receding northward. In 1837 this boundary, for example, ran somewhat south of the town of Mezen and was found at a depth of 2 m. In 1933 the Academy of Sciences Expedition found this boundary at the village of Semzha 40 km further north. ”

Section 156 of the Zubov book mentions fluctuations and noted periods of less or more ice. In the graphs it mentions ‘probability of presence of ice’ not that it was actually physically seen.

The ‘Arctic Circle’ was an organisation based in Ottawa. Their annual ‘Arctic circular’ provides fascinating insights into the period. These short excerpts do not do justice to the publication which details many interesting facts about all facets of arctic life in the 1940’s.

Note; Those interested in possible causes of the warming should read the report in full as it provides much weather related detail.

Note; Those interested in cosmic rays, sunspots and magnetic fields as possibly related to climate might usefully examine Page 78 onwards.

This item from 1949 refers to page 3 of this document;

http://www.thearcticcircle.ca/pdf/Arctic%20Circular%20Volume%202%201949.pdf

“During the last three decades there has been a marked change in the climate of the Arctic which is being felt throughout the northern hemisphere where, especially, the mean temperature of the winters has increased considerably. In the North American sector this change is perhaps best understood and also most marked in Greenland, where long meteorological records exist from a number of points on the west coast, Thus at Jakobshavn, in latitude 690 13 North, the mean winter temperature for the years 1913-1922 was about 5 degrees F above the mean of 50 years and that of 1923-1932 almost 10.0 degrees F. above. In 1935-1936 the mean for the winter at Godhavn was 13.40 higher than the normal at the end of last century, that of Godthaab 7.60 and at Julianehaab 9.8oF. Increasing temperatures are not limited to the air; sea temperatures also have increased and while the amplitude is not so great, the result is even more profound and far reaching.”

This from page 4

“The warming of the arctic seas has caused a diminishing of the arctic drift ice, which again has improved shipping conditions. In the 1907-1917 period Norwegian coal mines in Spitsbergen were able to load and export coal an average of 94 days each season, while 20 years later this period has been extended to 192 days. In 1878-80 Nordenskjold in the Vega was the first to navigate the North East Passage, but to do this he had to winter twice. In 1936 a convoy of fourteen Russian ships mode the trip in one season without encountering serious ice difficulties and during the last war this northern Sea route was used extensively by Soviet shipping. During 1942-45 even war ships, which are especially vulnerable to ice, were able to reach Thule without difficulty.

The seas around Greenland have also been remarkably open in later years. The east coast, which frequently remained completely blocked by pack-ice, in 1931-33 was almost free from ice. “

And this;

“In 1941-42 the low-powered, 80 ton R.C.M.P. schooner St. Roch made the North West Passage for the first time from the Pacific to the Atlantic and again in 1944 in the opposite direction in only 87 days.”

Historical note; Larsen, an Experienced arctic seaman who commanded the vessel noted;
The three seasons of the short Arctic Summers from 1940-42 had been extremely bad for navigation, the worst consecutive three I had experienced as far as ice and weather conditions were concerned, and in my remaining years in the Arctic I never saw their like.”

This allows us to observe that whilst Arctic conditions were often highly favourable for something like three decades, there were intermittent periods during the early years of World War 2 when the ice returned, but then abated again.

On page 5 is this observation;

“The warming of the arctic seas has profoundly affected marine life. The Irminger Current, that branch of the Gulf Stream which washes the south western part of Greenland’s west coast, can now be traced as far north as Melville Bay. The increase in sea temperature of Greenland waters, varying from 5 to 8 degrees F., has brought the Atlantic Cod and the halibut, besides numerous other Atlantic fishes to Greenland, so that today the fishing banks off the west coast are among the richest in the world. At the same time many arctic marine animals, including the beluga or white whale, the arctic cod and the capelin, to mention only a few, have retreated north. “

The next observation concerns the land rather than the sea;

“ In Finland, in northern Sweden and in Norway, the northern limits for agriculture have been advanced and the average growing season materially prolonged; likewise, seed production, natural afforestation and tree growth have increased markedly near the northern limit of forest.”

It also notes the harsh conditions in 1946 and 1947 and the exceptionally ice free conditions in 1948 on Page 17;

“Throughout the north mean temperatures were well above normal for the months of June and July except in the area of coastal and south-eastern Labrador (North East Canada). The highest temperatures recorded were in many cases 10 to 20 degrees (F) higher than the mean maximum computed over a considerable period of years. Arctic Bay (Canada) with a normal mean maximum of 510 F in July, reported a maximum temperature of 680 F and a mean temperature of 46°F as compared with the normal mean of 43°F. Nottingham Island with a mean maximum temperature of 490 F for July and a mean of’ 42°F reported a mean of 49 degrees F and a maximum of 680 F.”

(Mention is also made of very icy conditions in 1941)

And this;

“In this connection it is interesting to note that the amount of water released by the melting of glaciers has already caused a measurable increase in the level of the Oceans.”

Page 47 records a somewhat ironic outcome to intended cold weather experiments by the Royal Navy in February 1949;

“In the course of this (six week) cruise, the Vengeance penetrated more than 450 miles north of the Arctic Circle. Thirty-three special observers were aboard to watch trials on new methods of keeping guns, radio and radar equipment free from ice, the effects of extreme cold on the ship’s company, and the efficiency of the latest type of survival suit. The weather throughout was abnormal for that time of year, and instead of northerly winds and extremely cold weather there were southerly winds, with higher temperatures, strong gales and snowstorms, which restricted flying operations. Owing to these unexpectedly warm conditions the trials were stopped on March 4, a week ahead of schedule.”

A number of additional contemporary reports have been placed at the end of this article as a small fraction of the material available, demonstrating the widespread warming in the arctic and further afield over many years.

 

Section Six Observations and Comments


Modern Satellite observations and webcams that provide an hour by hour picture of every part of the arctic make it easy to forget that large areas of it had not even been even explored 80 years ago-let alone its ice extent minutely observed. This sense of remoteness is noted here by idiosyncratic explorer Vilhjalmur Stefansson

http://www.dartmouth.edu/~library/digital/collections/photographs/ocn237336112/friendlyarctic.html?mswitch-redir=classic#_ednref1

This from 28 October 1922

“In a letter to the Canadian Victoria Daily Times, Stefansson explained that the main object of his expedition was to explore the “area of a million or so square miles that is represented by white patches on our map, lying between Alaska and the North Pole.”

(Note; 100,000 square kilometers equals some 38,600 square miles)

This next item reinforces the notion of unexplored territory;

“National Geographic, Sept. 1934, pp. 261-304, “Flying Around the North Atlantic” by Anne Morrow Lindbergh. She and her husband crossed the icecap twice, followed the coastline, from Disko Bay area to Clavering Island, visited Dr.Lauge Koch’s research area, and literally ”redrew” the map of some areas of Greenland.”

The lack of data from Russia and other areas because its sheer remoteness made accurate data gathering problematic, large gaps in knowledge due to WW2 (i.e no DMI maps during this period) and the Cold war, uncertainty over final summer amounts as DMI usually did not record data after August and estimates by climatological methods means historic sea ice data is fragmented and incomplete. This is not helped by the different sea ice data bases often being at considerable variance with each other and changes in the way in which ice concentrations were calculated as described below;

“In 1968, The United States began reporting ice concentration in eights rather than tenths, then returned to tenths reporting in 1980. Canada retained the tenths format throughout the period. […….] SIC summary analyses in eights frequently overlay reconnaissance data which is plotted in tenths. Since SIC produced these charts for in-house, not public use, which of these formats is used is seldom noted on the charts….There is also a period when U.S. recon data receives a slightly different treatment from chart to chart…… With a good knowledge of codes and the history of code changes and a dash of intuition and care, it is possible to roam the data set without great fear of misinterpretation. Others entering without some preparation may find it hazardous.”http://www.nerc-essc.ac.uk/~olb/PAPERS/len19.pdf

Of course, professional arctic ice researchers are aware of these factors and adjust data accordingly but the preceding does raise the question as to whether x amount of ice in the satellite era (1979 onwards) is really the same as x amount in the period prior to that, derived through climatological or physical observations in often difficult conditions by such as whalers, which brings us to the thorny question of what the definition of ice actually is.

This was noted by the author in the library of the Scott Polar institute in Cambridge and has parallels in one of the news items previously quoted;

‘Observational data of the drifting station 1950-51-by M Somov -Volume 1 of 3 of this Russian North pole station on an ice floe.’

Middle of June onwards ‘the melting of the snow and ice took place very quickly although the air temperature remained close to freezing’

‘the sun shone…could walk about without a coat…some even tried to get a sun tan.’

‘because of the thaw an enormous amount of water accumulated on the ice’

‘walking was only possible if one wore high rubber boots reaching above the knees’ (because of the water sitting on the ice.)

‘many problems because of the thawing.’

The book described how later in the season some high spots became dry and these were little hillocks in a sea of icy water sitting on solid ice. This caused me to ask the following question of NSIDC;

“ …..how did pre satellite researchers estimating sea ice extent tell the difference between water, water floating on ice, and solid ice, and how can satellites differentiate between the three states? I was struck by Russian reports from the 1950’s at The Scott Polar institute in Cambridge when staff at the floating research stations commented about using Wellington boots in order to walk around the station, and how little dry ice islands eventually formed by the end of the summer surrounded by water on top of ice.”

I received the following reply from Julienne Stroeve ;(reproduced with permission)

“ … using passive microwave data it is very easy to tell the difference between ice and water as the dielectric constant differs quite a bit and this is reflected in large differences in the microwave emission. The main advantage of using passive microwave is that it can see the ice even if it’s cloudy or dark. There is a problem however in summer when melt ponds form on the ice since the sea ice algorithms then underestimate how much ice there really is (they think it’s open water). That’s one reason why we focus on extent rather than true ice area for the NSIDC sea ice news and analysis web site.
Visible and thermal imagery provides higher spatial resolution but is often hampered by clouds. Trying to do this work using earlier visible and thermal imagery requires the scientists to go through each image and manually filter out the clouds and determine where the ice is.”

 

The arctic in those pre satellite days was simply too large to be effectively and continually monitored. Observers getting close enough to the ice edge to make physical observations might be deterred from proceeding further by apparently impenetrable ice although better, more open conditions, might lie beyond. Data from such as the Russian sector – where much warming occurred, was not always taken into account. (However, the reader should be aware that, as Larsen noted, ice did sporadically return, whilst reports from 1939-45 are sparse for obvious reasons.)

In trying to determine the true extent of sea ice melt during the period we run the risk of comparing apples-physical observations, and oranges- satellite altimetry, and the different methods employed over the years creates uncertainties over whether each accurately picked up what is ice, what is water covered ice and what is open water. This makes it difficult to determine how modern ice extent compares to the past with any certainty.

However, the conclusion must be that drawn that warming was more widespread in the arctic generally -not just the Atlantic side-than is currently noted in the official sea ice data bases covering1920-1945/50 and that the official records appear to substantially overstate the ice area extent. Some of the thinning of the ice and reduction of glaciers noted today appears to have had their genesis in the period referenced, or earlier.

The 1920-1940’s arctic sea ice melt can therefore be seen as remarkable, albeit the caveats about apples and oranges need to be applied. Looking at the evidence available from each of the arctic oceans means the ice extent probably (but not certainly) lies somewhere within that experienced during the first half of the 2000’s, but was almost certainly not as low as 2007 and 2012, the causes of which are out with the scope of this paper.

We commenced this article with Skeptical Science and the Neven arctic sea ice blog, referencing the Sunday Times article paraphrasing Dr Christy as saying there is ‘anecdotal and other evidence suggesting similar melts from 1938-43 and on other occasions.” The assumption (by this author) being that he is comparing historic data with those of the modern era that commenced in 1979 with satellite measurements.

In that context the ‘similar melts from 1938-43’ seem unlikely, as this short period included a well referenced temporary increase in ice in at least two years, but ‘other occasions’ seems rather plausible. The 1930’s and 40’s were the two warmest consecutive decades in the record according to Professor Phil Jones (measured around Greenland-see reference for context) and there is a considerable body of scientific and anecdotal evidence suggesting the warming was widespread and lasted -with short remissions-for several decades.

No doubt the ‘Back to 1870’ project will objectively look at the available information from all sources and put the period to 1870-and especially 1920-1940/50- into its proper context to today.

This link “Supplementary information” leads to a variety of additional studies of the period, some modern, but most dating from the 1920-1940 era

http://curryja.files.wordpress.com/2013/04/supplementaryinformation29jan2013amednded-april2013.pdf

END

Update; From Florence Fetterer-. National Snow and Ice Data Center; ‘Back to 1870 group,’ responding to an email from the author. Early 2014

“The arctic-wide data base has still has not been released yet. However an Alaska database has been published, and you can learn about it here: https://accap.uaf.edu/?q=node/1048

The arctic-wide version will include all the data that are in this Historical Sea Ice Atlas For Alaska Waters , but it will not have the same user-friendly interface,  at least not in its first release.

Since we corresponded last, this data set has been released.

http://nsidc.org/data/g10007  It is based on the Danish charts and is one of the data sets that go into both the Alaskan Sea Ice Atlas and the arctic-wide one.”

Best,

Florence

(Note; The last link to nsidc shows all the ice data products available.)

An additional update has now been requested-August 2014

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71 thoughts on “Historic Variations in Arctic Sea Ice – Part Two

  1. So once again skeptics are right: Arctic ice is dynamic, with large swings in pack ice coverage which ebbs and flows over the years. Once again alarmists are wrong: Arctic ice is not in a deth spiral, nor is Arctic ice doing anythign unique or dangerous.

  2. I can’t possibly read all this while drunk. Maybe tomorrow afternoon. More likely Monday evening.

  3. It is a shame that you use NOAA/GISS temperatyure charts. They ar biased. Check actual stations in the high Arctic and you will find no warming trend in the max readings, and modest warming trend in the min readings. Recent high averages are very close to the late 1930s/early 1940s. The NOAA/GISS charts do not match the real available data.

  4. Dunno why u spread this Noaa/Giss stuff ? Check raw data n do it again. ” as seen in the graph” is not ok..n really Wuwt must know by now ?

  5. Note I made about 9 years ago
    July 2005
    Examination of the 50 odd temperature stations north of 63 that have records from 1935 to 2005 shows only a handful of stations with a recent peak year (2003, 2005 or 2006 depending on station) warmer than the peak year in the decade after 1935. In the vast majority the warmer peak is in the post 1935 decade. There is some evidence that the coldest years in the last decade are not as cold as in the post 1935 decade, but not enough to clearly support a claim of unprecedented warming. Peter Chylek et al. (2006) observed that recent warming in Greenland is neither faster nor higher than the 1930s, when CO2 could not have been the driver.

  6. CryoSat: Launched on April 8, 2010. Measuring the thickness of polar sea ice and monitoring changes in the ice sheets that blanket Greenland and Antarctica.
    Satellite records show a constant downward trend in the area covered by Arctic sea ice during all seasons, in particular in summer, with the minimum recorded occurring in the autumn of 2012. In October 2013, however, CryoSat measured about 9,000 cubic km of sea ice – a notable increase compared to 6,000 cubic km in October 2012.
    See http://www.esa.int/Our_Activities/Observing_the_Earth/CryoSat/Arctic_sea_ice_up_from_record_low

    Autumn sea-ice thickness from CryoSat 2010–2013, at

    http://www.esa.int/spaceinimages/Images/2013/12/Autumn_sea-ice_thickness_from_CryoSat_2010_2013

  7. Until the satellites came on stream we had no good quantified data regarding Arctic sea ice area and extent, just very limited observational data from the few people who visited this inhospitable area.

    We need at least 30y of satellite data as a base before we can get a glimmering of what’s happening in the Arctic, until then better to just say, “We don’t know.”

    Climate is not about short term fluctuations (weather). Climate is all about the long term.

  8. Good work, here. Note that DMI (going back to 1958) shows a lot of recent warming during winter season, but little variation during melt season (with record colds quite recent indeed).

  9. I don’t visit Neven’s blog anymore after he put up that offensive Hiroshima propoganda widget.

  10. evanmjones says:
    Good work, here. Note that DMI (going back to 1958) shows a lot of recent warming during winter season, but little variation during melt season (with record colds quite recent indeed).

    DMI uses the ERA-40 re-analysis which is not to be trusted:

    http://pielkeclimatesci.wordpress.com/2011/08/10/indictment-of-the-era-40-reanalysis-in-a-new-paper-erroneous-arctic-temperature-trends-in-the-era-40-reanalysis-a-closer-look-by-screen-and-simmonds-2011/

  11. In 2008, the Sierra Club endorsed Senator Barack Obama for President.

    For the record I’m a wascally Wepublican with zero respect for the current prez. That said, the above quoted remark was entirely gratuitous and certainly contributed nothing to the otherwise fine article.

  12. http://pielkeclimatesci.wordpress.com/2011/08/10/indictment-of-the-era-40-reanalysis-in-a-new-paper-erroneous-arctic-temperature-trends-in-the-era-40-reanalysis-a-closer-look-by-screen-and-simmonds-2011/

    “This study explicitly documents a discontinuity in the 40-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40) that leads to significantly exaggerated warming in the Arctic mid- to lower troposphere, and demonstrates that the continuing use of ERA-40 to study Arctic temperature trends is problematic.”

    The linked article is for mid-range model forecasts using ERA-40 being problematic. DMI does not use mid-range forecasts for it’s climate data collection, so this issue is irrelevant.

  13. Those historic estimates from climate science showing the Arctic sea ice at 11 M km2 (Kinnard 2011 above), that is what the sea ice is like in early June now.

    In early June, there is still substantial sea ice in Hudson Bay for example. The entire Arctic Archipelago is still completely iced-in at this time.

    How did the Hudson Bay Company establish fur trading posts at Churchill Manitoba in 1670 when Hudson Bay was iced-in all summer. Why did the pre-Dorset Eskimo live in this region as far back as 3,000 BC and invent kayaks when the entire area was iced in all summer.

    It is NOT believable (unless you are warming believer and fall for any fake hockey stick chart as if it were gospel).

  14. Interesting.

    Pity you used the “homogenised” GISS data though, it would be even more interesting – and a great deal more significant – without the Mann-made AGW bias.

  15. World’s Largest Ice Sheets Melting At Fastest Rate Ever Recorded
    The Huffington Post | By Jonathan Feldman
    Posted: 08/21/2014 4:13 pm EDT Updated: 08/21/2014 4:59 pm EDT

    What’s up with this?

  16. Being somewhat of a heat transfer geek, Just as a 1st order estimate: any radiative effect due to albedo has got to be outweighed 10X (if not 1000X) by the convective component once where is open water.

    The act of making winter ice releases huge amounts of latent heat to the atmosphere where it is ultimately radiated to space. Never mind the fact that open water means evaporation/sublimation at accelerated rates. Any fantasy of “Dark Water” absorbing enough radiant energy to counter this is a fantasy, especially given the angle of incidence when the high albedo ice is at a minimum.

  17. Tenuc says:
    August 22, 2014 at 4:25 pm

    We need at least 30y of satellite data as a base before we can get a glimmering of what’s happening in the Arctic, until then better to just say, “We don’t know.”

    We’ve had 35 ‘official’ years satellite data…actually goes back a few years before that, but using different satellites/methods and not daily coverage…but good enough to show trends.

  18. catweazle and others

    Whatever sceptics may think about it, GIss is an official and in many quarters respected measurement record. There is no point using other less accepted records that would be immediately discounted by those who we wish to influence.

    tonyb

  19. Very informative and useful post. Thanks. Agree with some of the comments that actual recorded temps from stations would be a useful addition. Taken as a whole however its very illuminating both on the amount of uncertainty and the likely extent of previous fluctuations.

  20. Mwhite

    My 90 year old neighbour was on the arctic convoys to Murmansk. He says that the iciest part of the journey on the year he went was the frosty welcome from the Murmansk governors who would not let them into town without minders.

    tonyb

  21. Here is a satellite issue recently highlighted by Dr. Susan Crockford.

    Polar Bear Specialist Group (PBSG)
    Minutes of the 17th Meeting of the IUCN/SSC Polar Bear Specialist Group, Fort Collins, Colorado, USA 9-14 June 2014

    Defining sea-ice thresholds are important because there can be a big difference in the
    measured length of “ice-free” periods depending on whether 50% coverage or 30% coverage is
    the threshold used. Another important piece of information is how long a polar bear can go
    without access to sea ice;……[page 22]

    There was further discussion on sea ice thresholds and that telemetry and sea ice do not always
    line up. For example, recent analysis shows that up to 20% of locations of collared females are
    in areas where the ice data indicates there is no ice
    .

    http://pbsg.npolar.no/export/sites/pbsg/en/docs/PBSG17-minutes-FINAL.pdf

    [page 23]

  22. Looking at the picture above of the Arctic Circle, 5 of the 12 ‘slices’ (40%) that make up the Arctic Circle are Russian territory. If this rapid, unprecedented warming is really happening globally, why aren’t we hearing about these drastic changes in this region on a constant basis?

    Is Gazprom Russian for Kock Brothers? :)

  23. Further to “The Early Twentieth-Century Warming in the Arctic—A Possible Mechanism” here are some more. Apologies if I’ve duplicated any below.

    Abstract
    Abstract
    The regime shift of the 1920s and 1930s in the North Atlantic

    During the 1920s and 1930s, there was a dramatic warming of the northern North Atlantic Ocean. Warmer-than-normal sea temperatures, reduced sea ice conditions and enhanced Atlantic inflow in northern regions continued through to the 1950s and 1960s, with the timing of the decline to colder temperatures varying with location. Ecosystem changes associated with the warm period included a general northward movement of fish……
    dx.doi.org/10.1016/j.pocean.2006.02.011
    ————

    Abstract
    Early 20th century Arctic warming in upper-air data
    Between around 1915 and 1945, Arctic surface air temperatures increased by about 1.8°C. Understanding this rapid warming, its possible feedbacks and underlying causes, is vital in order to better asses the current and future climate changes in the Arctic.

    http://meetings.copernicus.org/www.cosis.net/abstracts/EGU2007/04015/EGU2007-J-04015.pdf

    ————

    Abstract
    …..Winter season stable isotope data from ice core records that reach more than 1400 years back in time suggest that the warm period that began in the 1920s raised southern Greenland temperatures to the same level as those that prevailed during the warmest intervals of the Medieval Warm Period some 900–1300 years ago. This observation is supported by a southern Greenland ice core borehole temperature inversion……
    Climatic signals in multiple highly resolved stable isotope records from Greenland

    http://www.sciencedirect.com/science/article/pii/S0277379109003655

  24. Thank you tonyb, so much here from the historical record. I will read in detail over
    the next two days but note the primary Russian records of the 1930’s, Pisarov,
    Zubov, Altman indicating that there was Arctic warming prior to GHG concentrations..

    Down Memory Lane:
    When I read your long historical record, beyond the IPCC’s back to the seventies
    quickie, yr CET records and voluminous farmers records, ships’ records, church
    records, re crop failure and weather, ice fairs on the Thames, opening of northern
    ports and North West Passage, advance and retreat of Alpine glaciers, I think of
    another ‘on the record’ comment which is relevant to climate science, a comment
    by Winston Churchill regarding our human built in checking devices, ‘what is
    called in military terms, taking ‘cross bearings,’ ‘independent testimony’ ‘ to a
    conjectured reality.

    We have seen the criticisms of ‘anecdotal’ (?) climate models, problems with
    what goes in, number of trees in a tree ring sample, problems with tree rings
    as a temperature proxy, methodology, funding pressures, unknowns, clouds
    n’ such, but with the historic record, when it’s not the sus public proclamations
    of leaders, but log books, almanacs, ‘we were there,’ the crop failed,’ these
    constitutes valuable primary documentation, no cui bono.

  25. This is so long my confirmation bias is creeping in before I finish. I may not be able to make legitimate criticisms.

    But it seems like a lot is hanging on the 1930s and 40s being as warm as Phil Jones says they were in the North. Is that a legitimate peg to hang it on? Phil Jones only claimed a regional warming (correctly from his evidence) and the Arctic as a whole is a lot bigger.

    A natural oscillation sounds right to me, but I remain unconvinced it is proven.
    Sorry.

  26. Pretty important reading, I should think. Perhaps Russian interest in warm water ports and warmer agricultural belts means they’ve had that hockeystick in the rack all along.

  27. With thanks to Mr. Brown, all in all an excellent review, took some time to read (I had it split three sessions).
    As far as quality of data is concerned, us the ordinary mortals are helpless , we have to use what is available, despite ‘daily’ blatant attempts to change data on everything which might have any bearing on the climate variability.
    However, there is still one good quality set of the ‘near Arctic’ data, the Reykjavik atmospheric pressure, it has been measured at the same location for nearly 150 years. It is simply nature of things that barometric pressure is far less sensitive to the precise location than the thermometric temperature measurement.
    Fortunately no one bothered to fiddle with it, since the ‘experts’ have not understood its importance for the movements in the North Atlantic SST SST vs Atmospheric pressure
    If the history is to repeat itself, then the cooling in the North Atlantic and consequently increase in the Arctic ice coverage can not be far off.

  28. Bill Illis
    I agree, the chart here from 1662

    http://ageofex.marinersmuseum.org/index.php?type=explorersection&id=285

    A Chart of Hudson’s Straights and Bay of Davis Streights, and Baffin’s Bay as Published in the Year 1662,” An Account of a Voyage for the Discovery of a North-West Passage by Hudson’s Streights, to the Western and Southern Ocean of America, 1748-49, From The Library at The Mariners’ Museum, G650.1746.D75 .

    It looks like the West Coast of Greenland was Ice Free up to about 80’N and it was possible to sail round Baffin Island,

  29. The cooling in the 1940’s was brief, it warmed again at times in the 1950’s and early 1960’s, as we can see with the AMO:

    http://www.woodfortrees.org/plot/esrl-amo/from:1920/to:1972

    Personally I think that the AMO warming is associated with increases in negative North Atlantic Oscillation episodes. While increased forcing of the climate produces increasingly positive NAO conditions.

  30. thank you tonyb for taking the time to compile this information . having it all in one place certainly increases the impact over reading snippets here and there . the list of historical information that runs contrary to the current unprecedented meme is the primary reason for my scepticism .

    tony heller also does a fantastic job of finding similar reports,papers and news snippets regarding the temperature series in the northern hemisphere.

  31. ” large gaps in knowledge due to WW2 (i.e no DMI maps during this period) and the Cold war”

    “reports from 1939-45 are sparse for obvious reasons.”

    One often sees claims like these, but I would suggest the opposite is true, but that the data have simply not been searched for.

    For example the Royal Navy patrolled the ice edge in Denmark Strait continuously during WW II to prevent german surface vessel breaking out into the Atlantic. One just has to check the log books to get data on the ice edge position.

    The Murmansk Convoys 1942-45 hugged the ice-edge to keep as far away as possible from German air bases. For example to find the position of the ice edge in Barents Sea in the summer of 1942 (convoy PQ 17) you just have to check Roskill’s official history. For other convoys you have to do a bit of digging, but the data is there, even for the winter seasons (for example I remember seeing a map of the ice-edge position in the Barents Sea in late December 1943 in a German report on the sinking of the Scharnhorst).

    In summer 1943 USAAF photographed all of Greenland to make a reliable air navigation chart. The photos still exist and show where the ice edge was situated.

    Several times in winter (e. g. 1942/43) convoys diverted around german submarine wolfpacks came far enough north to encounter sea-ice near Greenland. The position of the ice can be found in the convoy reports.

    Both the Allies and the Germans repeatedly sent small expeditions to Northeast Greenland and Spitzbergen to establish, maintain (and attack) weather observers, most of the logs and records from these forays are extant.

    There were also a number of larger german forays into arctic waters for example the raider Komet went through the northeast passage in autumn 1940 (and found it largely ice-free), Operation Wunderland in the Kara Sea east of Novaya Zemlya in August 1942 and the attack on Spitzbergen (Operation Sizilien) in September 1943.

    In short I don’t think there is less information on the ice in the Atlantic sector of the Arctic in 1939-45 than in the periods before and after, it is just to be found in other places. The same probably applies to the Bering Sea, where there was a lot of activity by the US Navy during WW II.

    And as for the Cold War. Why has no-one apparently used the HUGE amount of declassified imagery from the Corona recce satellites 1960-1972? For example the very first photograph ever taken from orbit and successfully recovered in August 1960 shows that the waters around Mys Shmidta in Chukotka were completely ice-free at the time. In particular the imagery from the KH-5 Argon mapping cameras is very suitable for determining ice conditions.

  32. tty

    the period from 1960 is outside the scope of this article but I certainly expect to look at Corona data when I try to see what happened between around 1950 and 1979.

    There was less ‘official’ information (such as DMI maps) about the arctic during the second world war. I spent some time at the archives of the Scott polar institute in Cambridge together with the library there (from where some of this information comes) I hope to be there again next month for further research. I have also looked at the Met office library who due to their involvement in D-daythey have a good section on the war.

    Speaking to my neighbour who was a veteran of the Murmansk convoys the last thing on their minds was recording the sort of information they may have done during peace time. I also regularly read ships logs.

    If you have access to a book on the period in the arctic that brings all this war time material together I will gladly examine it.
    tonyb

  33. Matt G says:
    August 22, 2014 at 5:49 pm […]The linked article is for mid-range model forecasts using ERA-40 being problematic. DMI does not use mid-range forecasts for it’s climate data collection, so this issue is irrelevant.

    You’re wrong. You’re seemingly mixing up the name of the organisation in the acronym with the identified problem which has nothing to do with forecasts. The problem is that the reanalysis of the temperature observations from 1958-2002 in the Arctic is wrong because it shows too much warming.
    DMI does use ERA-40 in the graph evanmjones referred to, look:

    http://ocean.dmi.dk/arctic/meant80n.uk.php

  34. J Philip Peterson

    Yes, there is a lot of information as I hope people will be able to use the article as useful reference material

    I referenced the data you mention in the first half of the article as follows;

    “The Danish Meteorological Institute yearbooks mentioned are online from 1893-1956 and from which this explanatory quote is taken;

    http://nsidc.org/data/docs/noaa/g02203-dmi/

    The positions of direct observations are marked on each chart with red dots (Figure 1). Each chart shows the mapmakers’ inferred ice edge as well as the type of ice present, for example large ice fields or new ice, in certain locations….’

    —— ——-

    I also mention that generally September records were not kept which is when a lot of melting occurs in certain years.
    tonyb

  35. FergalR says:
    August 23, 2014 at 8:15 am
    Matt G says:
    August 22, 2014 at 5:49 pm […]The linked article is for mid-range model forecasts using ERA-40 being problematic. DMI does not use mid-range forecasts for it’s climate data collection, so this issue is irrelevant.

    You’re wrong. You’re seemingly mixing up the name of the organisation in the acronym with the identified problem which has nothing to do with forecasts. The problem is that the reanalysis of the temperature observations from 1958-2002 in the Arctic is wrong because it shows too much warming.
    DMI does use ERA-40 in the graph evanmjones referred to, look:

    http://ocean.dmi.dk/arctic/meant80n.uk.php

    —————————————————————————————————–

    The DMI does use ERA-40, but only the first day where observations are used for each of the hours 00, 06, 12, 18 at that time when +0hr. The data used is that which starts the NWP models so they are the original data not future forecast data. They are very good in comparing years, but should not be used as a physical mean of temperature.

    “The temperature graphs are made from numerical weather prediction (NWP)
    “analysis” data. Analyses are the model fields used to start NWP models. They
    represent the statistically most likely state of the atmosphere, given the
    information available to make the analysis. Since the data are gridded, it is
    straight forward to deduce the average temperature North of 80 degree North.
    However, since the model is gridded in a regular 0.5 degree grid, the mean
    temperature values are strongly biased towards the temperature in the most
    northern part of the Arctic! Therefore, do NOT use this measure as an actual
    physical mean temperature of the arctic. The ‘plus 80 North mean temperature’
    graphs can be used for comparing one year to an other.”

    “In the plot, the red curve is based on the average 2 m temperatures north of 80
    degree North, from the twice daily ECWMF analyses. These are gradually becoming
    better and more detailed, as the NWP model system at ECMWF is improved with
    time. That is why the name shift with time (e.g. from T799 to T1279 in year
    2010).”

    The paper review was concerning ER-40 for especially around 5 days or longer and this is well known, the model is poor at this range in the Arctic. The criticism was for future forecast(s) modeled data run after the initial data that starts the NWP. (+72, +96, +120, +144 and +166 etc)

    “The accuracy of the medium-range forecasts run to 10 days ahead from each of
    the 00 and 12 UTC ERA-40 analyses provides a further indication of the quality of the
    analyses and of the observing system on which they are based. Short-term variations in
    accuracy over periods in which little change to the observing system occurred provide
    indications of natural variations of atmospheric predictability.”

    “The medium-range forecasts for 2001 from
    ERA-40 are accordingly not as accurate as the corresponding operational forecasts.
    Improvement of the operational system has, however, occurred at such a pace that the
    ERA-40 forecasts are similar in skill to the operational forecasts of the late 1990s.”

    “ERA-40 are a welcome result provided they do not stem from a failure of the analysis
    to draw appropriately to observations. An acid test is whether short-range forecasts run
    from the ERA-40 analyses fit observations better. This is indeed the case.”

  36. !The problem is that the reanalysis of the temperature observations from 1958-2002 in the Arctic is wrong because it shows too much warming.”

    In the paper you linked originally there is no analysis of the observed ERA-40 data at 00, 06, 12, and 18. All the criticisms were based on analysis for forecast data at least 24 hours ahead and the main criticism was based on the medium range forecast.

  37. Tony
    Have you ever seen the book “The Arctic Basin, results from drifting Arctic stations” by Ivan Frolov in your library resources? I haven’t found it near me, but it sounds like something to check out.

  38. A reader

    I think I saw it in the met office library. I reference the Somov book from 1950 on drifting ice in the article but will look out for the Frolov book next time I am at the Met office. Thanks

    Tonyb

  39. Thanks Tony for your historical sleuthing. I really appreciate this update to your Climate, Etc. guest piece. Among my frustrations with contemporary climate science is the dismissive attitude toward climate history based on growing season records and the many other anecdotal records,
    You cite much more than the anecdotal, Finding and publishing these studies in one place is a very valuable contribution. I hope those anticipating a career in climatology are reading this!

  40. Thanks Tony, fine work.
    Who holds the Hudson Bay Companies Journals?Britain? Or Canada?
    Of course you realize you are engaging in heresy, as there is no climate history prior to the declaration of The Mann.
    And that history is as poison to the fantasy of the magic gas.
    Please keep up the great work.

  41. FergalR says:
    August 23, 2014 at 3:13 pm
    Matt G,
    First you say that DMI doesn’t use ERA-40, now you say they do and you quote at length, but don’t link to a .pdf on DMIs site.
    Here it is: http://ocean.dmi.dk/arctic/documentation/arctic_mean_temp_data_explanation_newest.pdf

    It was created before the publication of the problems with ERA-40.

    I look forward to your next excuse.

    ———————————————————-

    I never typed that DMI doesn’t use ERA-40 so please stop making things up. Your confusion is blaming criticism for forecasts ahead compared with data originally used before putting into NWP models.

    “The linked article is for mid-range model forecasts using ERA-40 being problematic. DMI does not use mid-range forecasts for it’s climate data collection, so this issue is irrelevant.”

    In the article you linked when you actually read the full version, the problems are only related to forecasts at least 24 hours ahead.

    http://pielkeclimatesci.wordpress.com/2011/08/10/indictment-of-the-era-40-reanalysis-in-a-new-paper-erroneous-arctic-temperature-trends-in-the-era-40-reanalysis-a-closer-look-by-screen-and-simmonds-2011/

  42. “If you have access to a book on the period in the arctic that brings all this war time material together I will gladly examine it.
    tonyb”

    Sorry, there isn’t any, the data has never been collected. I’ve personally seen bits and pieces of it so I know it does exist. For example the passage of the Komet through the northeast passage in august-september 1940 (and ice conditions) is described in some detail in Robert Eyssen “Hilfskreuzer Komet, Kaperfahrt auf allen Meeren” (1960).

    Another example: here is a track chart for Admiral Scheer during Unternehmen Wunderland 16-31.8 1942.: http://www.wlb-stuttgart.de/seekrieg/4208-bilder/wunderland.jpg
    Since the Scheer strangely enough completely lacked icebreaking capability and kept away from ice it indicates that there was about as little ice in the Kara Sea in August 1942 as in August 2014.

  43. O/T I’VE RECEIVED NO EMAILS TODAY, ANYTHING WRONG? i KEEP GETTING SOME AD ON THE TOP OF MY EMAILS TOO, AND I CAN’T REMOVE IT.

  44. In my opinion, in this graph we can see a fairly good rough estimate of Arctic sea ice extent between 1880 and 2011: http://diablobanquisa.files.wordpress.com/2013/10/image001-e1380906737960.png

    So… Which is the sea ice extent dataset? None, but a temperature dataset (inverted, so that higher temperatures correspond to less ice and vice versa): annual Arctic (64-90ºN) temperature anomalies between 1880 and 2011 (NASA GISS data – meteorological stations only).

    The most widely used dataset of arctic sea ice extent is Chapman&Walsh. I’ll compare the GISS temperature data (inverted) with Chapman&Walsh summer sea ice extent: http://diablobanquisa.files.wordpress.com/2013/10/image005-e1380906773166.png

    What happens between 1920 and 1955? The two series are no longer correlated, and the temperature rises without any effect on the ice pack… according to Chapman&Walsh.
    And, what happens if we compare with a Russian dataset that covers the 77% of the Arctic?: http://diablobanquisa.files.wordpress.com/2013/10/image007-e1380906721711.png
    The Russian dataset correlates fairly well with the temperature, and in the troubled period 1920-1950 clearly better than Chapman & Walsh does.

    Chapman & Walsh: http://arctic.atmos.uiuc.edu/SEAICE/timeseries.1870-2008
    GISS: http://data.giss.nasa.gov/gistemp/tabledata_v3/ZonAnn.Ts.txt
    Russian dataset: http://nwpi.krc.karelia.ru/e/climas/Ice/Ice_no_sat/XX_Arctic.htm

  45. Yes, the high temperatures in the Arctic for two or three decades simply aren’t reflected in the ice melt data. Chapman and Walsh are involved in the Back to 1870 project. Florence Fetterer tells me we can expect this to go online in late September.

    tonyb

  46. Both the NE Passage along Siberian coast & the NW Passage along Alaska & Canada were open during the 1930s & ’40s (from Wiki, but sourced):

    Northeast

    In 1932, a Soviet expedition led by Professor Otto Yulievich Schmidt was the first to sail all the way from Arkhangelsk to the Bering Strait in the same summer without wintering en route. After a couple more trial runs, in 1933 and 1934, the Northern Sea Route was officially defined and open and commercial exploitation began in 1935. The next year, part of the Baltic Fleet made the passage to the Pacific where armed conflict with Japan was looming.

    A special governing body Glavsevmorput (Chief Directorate of the Northern Sea Route) was set up in 1932, and Otto Schmidt became its first director. It supervised navigation and built Arctic ports.

    During the early part of World War II, the Soviets allowed the German auxiliary cruiser Komet to use the Northern Sea Route in the summer of 1940 to evade the British Royal Navy and break out into the Pacific Ocean. Komet was escorted by Soviet icebreakers during her journey. After the start of the Soviet-German War, the Soviets transferred several destroyers from the Pacific Fleet to the Northern Fleet via the Arctic. The Soviets also used the Northern Sea Route to transfer materials from the Soviet Far East to European Russia, and the Germans launched Operation Wunderland to interdict this traffic.

    Northwest

    Canadian RCMP officer Henry Larsen was the second to sail the passage, crossing west to east, leaving Vancouver 23 June 1940 and arriving at Halifax on 11 October 1942.[45] More than once on this trip, it was unknown whether the St. Roch a Royal Canadian Mounted Police “ice-fortified” schooner would survive the ravages of the sea ice. At one point, Larsen wondered “if we had come this far only to be crushed like a nut on a shoal and then buried by the ice.” The ship and all but one of her crew survived the winter on Boothia Peninsula. Each of the men on the trip was awarded a medal by Canada’s sovereign, King George VI, in recognition of this notable feat of Arctic navigation.

    Later in 1944, Larsen’s return trip was far more swift than his first; the 28 months he took on his first trip was significantly reduced, and he took 86 days to sail back from Halifax, Nova Scotia to Vancouver, British Columbia,[46] setting the mark for having traversed it in a single season. The ship followed a more northerly partially uncharted route, and it also had extensive upgrades.

  47. Anthony, I don’t know if you’ll read this (or be notified of this comment), but I’ve written a blog post on the fact that for the second year in a row, it’s possible to sail past the 85N parallel. This year it could go even further, depending on the weather. I’ve skimmed through your post here a couple of times, and don’t see any anecdotal evidence of this happening before, except fora 1922 Norwegian expedition “sailing as far north as 81°29′ in ice-free water.” Do you know of any other evidence?

    Same goes for the Northern Sea Route. I know much or even all of it was open and navigable during several years in the 1930’s etc, but this year is the 7th year in a row it has fully opened op from East to West.

  48. Neven

    Always good to read your thoughts.

    As for the Northern sea route it was certainly open at times in the 1920’s most or all of the thirties and intermittently in the 40’s.

    My neighbour was on the WW2 arctic convoys and took an interest in it before and since so there are certainly parallels to today.

    Did you see the article about 1960’s ice and the comment from Dr Susan Crockford?

    http://wattsupwiththat.com/2014/09/04/1960s-satellite-imagery-of-polar-ice-discovers-enormous-holes-in-the-sea-ice/

    It concerns the enormous holes found in the sea ice via early 1960’s satellite imagery just rediscovered.

    Susan Crockford of Polar Bear science made this comment ;

    http://wattsupwiththat.com/2014/09/04/1960s-satellite-imagery-of-polar-ice-discovers-enormous-holes-in-the-sea-ice/#comment-1727593

    The estimate for the period according to Walt Meier is lower than Hadley states and my estimates are that the lowest of the 1920 to 1950 ice extent period was lower than his 1964 estimate. I don not think it matches 2007 or 2012
    tonyb

  49. Neven

    This from my article of 2009 concerning the arctic melting of the 1820’s. As regards going further North, in previous times they had neither Radar nor Satnav to help their navigation so its comparing apples and oranges.

    .

    http://wattsupwiththat.com/2009/06/20/historic-variation-in-arctic-ice/

    “Intriguingly “Mr. Scoresby, a very intelligent young man” had a renowned father. Whilst Scoresby (senior) like his fellow Whitby neighbour James Cook did not gain this £20,000 reward either, he did reach beyond 81 degrees in 1806, breaking through the ice at Spitzbergen only 510 miles from the North Pole. This achievement was not bettered for 21 years, and then only by travelling for some of the way over the ice, not on board a ship. “

    —— ——-

    Contemporary reports from the time include the following 1817 book;

    http://books.google.co.uk/books?id=EpwSAAAAYAAJ&dq=illustrations+of+greenland+1817&printsec=frontcover&source=bl&ots=3cjiizphFa&sig=nFNcBtJE-Bv3DDAf9U4lK2Y-JYg&hl=en&ei=1eEySpGRB4iZjAeItuyBCg&sa=X&oi=book_result&ct=result&resnum=1

    “We learn that a vessel is to be fitted out by Government for the purpose of attempting again the north-west passage, the season being considered as peculiarly favourable to such an expedition. Our readers need not be informed that larger masses of ice than ever were before known have this year been seen floating in the Atlantic, and that from their magnitude and solidity, they reached even the fortieth latitude before they were melted into a fluid state. From an examination of the Greenland captains, it has been found that owing to some convulsions of nature , the sea was more open and more free from compact ice than in any former voyage they ever made: that several ships actually reached the eighty-fourth degree of latitude, in which no ice whatever was found; that for the first time for 400 years, vessels penetrated to the west coast of Greenland, and that they apprehended no obstacle to their even reaching the pole, if it had consisted with their duty to their employers to make the attempt.”

    As far as the Northern Sea route goes it would seem from Russian sources that credibly it was possibly open around the 1530’s according to information I researched at the Scott Polar Institute in Cambridge a couple of years ago. I hope to follow up my visit there with another in a few weeks time to see if I can find any more information.
    tonyb

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