Arctic Ice and the AMO

By Paul Homewood

 

David Rose’s piece in the Mail on Sunday has already been picked by WUWT and Bishop Hill, amongst others. But I want to concentrate on one aspect, that of cycles.

The Mail report:

However, Dr Hawkins added that the decline seen in recent years was not caused only by global warming. It was, he said, intensified by ‘natural variability’ – shifts in factors such as the temperature of the oceans. This, he said, has happened before, such as in the 1920s and 1930s, when ‘there was likely some sea ice retreat’.

Dr Hawkins said: ‘There is undoubtedly some natural variability on top of the long-term downwards trend caused by the overall warming. This variability has probably contributed somewhat to the post-2000 steep declining trend, although the human-caused component still dominates.’

Like many scientists, Dr Hawkins said these natural processes may be cyclical. If and when they go into reverse, they will cool, not warm, the Arctic, in which case, he said, ‘a decade with no declining trend’ in ice cover would be ‘entirely plausible’.

Peer-reviewed research suggests that at least until 2005, natural variability was responsible for half the ice decline. But exactly how big its influence is remains an open question – and as both Dr Hawkins and Prof Curry agreed, establishing this is critical to making predictions about the Arctic’s future.

Prof Curry said: ‘I suspect that the portion of the decline in the sea ice attributable to natural variability could be even larger than half.

‘I think the natural variability component of Arctic sea ice extent is in the process of bottoming out, with a reversal to start within the next decade. And when it does, the reversal period could last for several decades.’

This led her to believe that the IPCC forecast, like Al Gore’s, was too pessimistic.

‘Ice-free in 2050 is a possible scenario, but I don’t think it is a likely scenario,’ she concluded.

The cycle they refer to is the Atlantic Multidecadal Oscillation, AMO. Below is the detrended AMO, and you can see it runs on about a 60-year cycle. It is currently around or just below its peak, having risen strongly since the mid 1970’s.

It may remain at the current level for a few more years yet, but it will then fall away for the next 30 years, just as it did from the 1940’s to the 1970’s.

 

us-tor-probs

http://www.esrl.noaa.gov/psd/cgi-bin/gcos_wgsp/tsanalysis.pl?tstype1=91&tstype2=0&year1=1895&year2=&itypea=0&axistype=0&anom=0&plotstyle=0&climo1=&climo2=&y1=&y2=&y21=&y22=&length=&lag=&iall=0&iseas=1&mon1=0&mon2=11&Submit=Calculate+Results

 

 

So, what effect will this have on Arctic ice? We can glean much from examining temperature trends around the part of the Arctic affected by the AMO.

 

First, Iceland. Below is a report from the Icelandic Met Office in 2008, “Past temperature conditions in Iceland from 1798 to 2007”, which uses the long running, high quality site of Stykkisholmur.

 

Temperature in Stykkishólmur (Western Iceland)

The temperature (figure 1) has in the long run been increasing during the last 200 years at the rate of +0.7°C per century. This is similar to the general temperature increase in the whole Northern hemisphere during the same period. The warming has been very uneven, dominated by three cold periods and two warm ones.

 

Annual temperature in Stykkishólmur 1798 to 2007

Stykkishólmshiti

Figure 1. Annual temperature in Stykkishólmur 1798 to 2007. Note that the values prior to 1845 are interpolated from observations at other stations. The confidence is very low for the years before 1830 and the values are preliminary and should not be referenced. Work on quality improvement is ongoing. A few warm and cold years are highlighted.  

 

The time from 1925 onwards is dominated by a very large cycle that does not show an overall significant warming, although the temperature rise of the last 20 years is considerable.

There is also a large decedal variability before 1925. The year 1892 marked the end of a period dominated by a very large year-to-year variability and the end of a long run of very cold years. There was a relatively warm period during 1837 to 1858, and by overlooking the very cold year of 1835 and a few isolated cold months one can identify the interval 1813 to 1858 as a generally warm one.

The years 1807 to 1812 were very cold. Although the following warm period was considerably colder than the corresponding 20th century warm period it was noted as a generally favourable time for agriculture and the population of the country increased markedly.

The 20th century warm period that started in the 1920s ended very abruptly in 1965. It can be divided into three sub-periods, a very warm one to 1942, a colder interval during 1943 to 1952, but it was decisively warm during 1953 to 1964.

The cold period 1965 to 1995 also included a few sub-periods. The so called “sea ice years” 1965 to 1971, a slighly warmer period 1972 til 1978, a very cold interval during 1979 to 1986, but therafter it became gradually warmer, the last cold year in the sequence being 1995. Since then it has been warm, the warmth culminating in 2002 to 2003. Generally the decription above refers to the whole country, but there are slightly diverging details, depending on the source of the cold air.

 

Note:

1) The reference to a long term temperature increase since 1798.

2) No significant warming since 1925.

3) Reference to cold and warm periods. The most recent ones being the cold period from 1965 to 1986, followed by the recent warming. Note how these, and the warm period culminating in the 1940’s, correspond with the rise and fall of the AMO.

If we look further afield, we find patterns in Greenland (Godthab and Angmassalik), Norway (Vardo) and Russia (Murmansk and Salehard). The following graphs are from GISS, and use unadjusted data.

 

station

 http://data.giss.nasa.gov/cgi-bin/gistemp/show_station.cgi?id=431042500000&dt=1&ds=1

station

 http://data.giss.nasa.gov/cgi-bin/gistemp/show_station.cgi?id=431043600000&dt=1&ds=1

 station

http://data.giss.nasa.gov/cgi-bin/gistemp/show_station.cgi?id=634010980003&dt=1&ds=1

station

http://data.giss.nasa.gov/cgi-bin/gistemp/show_station.cgi?id=638221130005&dt=1&ds=1

station

http://data.giss.nasa.gov/cgi-bin/gistemp/show_station.cgi?id=222233300002&dt=1&ds=1

All these stations, ranging from western Greenland to Siberia, show essentially the same pattern, a warm period around 1940, comparable to now, and a much colder interlude in the  1960’s and 70’s. And, of course, these all closely follow the ups and downs of the AMO.

There seems little doubt that the Arctic will be in for another cold period during the next 30 years or so, and that, as Judith Curry indicates, we will see a long term recovery of Arctic ice extent.

We fail to learn the lessons of history at our peril!

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44 thoughts on “Arctic Ice and the AMO

  1. My cynicism overflows.
    This information was front and centre prior to the CAGW orchestration.
    Every shipping company that worked the Arctic Seas, …arggh.It is like the comic books.
    “And suddenly, with nowhere else to go, Climatology ™ IPCC, discovered natural cycles.”

  2. I wonder how much information that could be lost or hidden by the varius homogenisations.
    I remember Reykjavik that in the Giss version looked very different form the original Icelandic.

  3. Yep interesting times for the bozos trying to sail, paddle or cruise the Northwest “passage”.
    The Russians, meanwhile, are building monster nuclear ice breakers and you may have noticed that they just took back their only winter ice-free deep water port……

    • I hadst realized that Putin had taken back an area so vital to Russian affairs. Putin was planing ahead and now this makes it full circle.. and why he was hell bent on getting it this year. If they are ice locked their trade dwindles.

      Something to ponder..

  4. If the computer models are left out of it all that can be said is “that it happened before and will most likely happen again, but we know not to what extent and exactly when”.

  5. There seems little doubt that the Arctic will be in for another cold period during the next 30 years or so, and that, as Judith Curry indicates, we will see a long term recovery of Arctic ice extent.

    Presumably, this explains the sudden priority given to getting a ‘UN climate agreement (not a treaty)’ agreed in Paris next year, before the AMO starts everything cooling to an extent that even new algorithms and homogenizations cannot hide.

    • I have always said these people are aware of natural cycles – thus the screams of “we must act now! Time is running out” and all that. Time is running out alright and the jig will soon be up.

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

      The huge warming of the Arctic that started in the early 1920s and lasted for almost two decades is one of the most spectacular climate events of the twentieth century. During the peak period 1930–40, the annually averaged temperature anomaly for the area 60°–90°N amounted to some 1.7°C…..
      dx.doi.org/10.1175/1520-0442(2004)017%3C4045:TETWIT%3E2.0.CO;2
      ————

      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

      ————

      IPCC – AR4
      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.

      http://www.ipcc.ch/publications_and_data/ar4/wg1/en/spmsspm-direct-observations.html

      ————

      Abstract
      Arctic Warming” During 1920-40:
      A Brief Review of Old Russian Publications
      Sergey V. Pisarev
      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…..

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

      ————

      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

    • The CAGW people were hell bent to get a treaty signed at Hoaxahagen. Fortunately, it didn’t happen. Or disaster, it didn’t if you were supporting it. My position on the UN has gone from benign neglect (didn’t care one way or the other) to the UN should relocate to some other country. Get the UN out of the US. Our enemies use the UN to launch propaganda and spy on the US. It is also a convenient way of bringing in people that shouldn’t be here.

  6. Arctic climate scientists are well aware of this. The problem is they can’t see past the rim of the pig trough.

    • “… they can’t see past the rim of the pig trough. …”

      I like that very pungent turn of the phrase.

  7. “The time from 1925 onwards is dominated by a very large cycle that does not show an overall significant warming, although the temperature rise of the last 20 years is considerable.”

    2) No significant warming since 1925.

    somebody needs to learn how to write better or read better or supply the actual tests.

    • Steven, you are familiar with cycles, so you know precisely what is meant.

      Look at Figure 1. You like doing linear projections so do one along the data from 1925 to present on that temperature series. It will show no significant warming.

      If you cherry pick a start date of say 1990 there is a considerable temperature rise. This is the basis of all the current manufactured alarm.

    • somebody needs to learn how to write better

      Is that supposed to be an example of irony by design or did that just happen when you weren’t looking?

  8. Who else has a horrible feeling, that as the Arctic recovers, they will say that it is a sign of warming, and one or two models predicted it? Remember, ice build in the Antarctic is (to them) a sign of warming, so ice build in the Arctic will be too.

  9. Dr Hawkins said: ‘There is undoubtedly some natural variability on top of the long-term downwards trend caused by the overall warming.

    Prof Curry said: ‘I suspect that the portion of the decline in the sea ice attributable to natural variability could be even larger than half. … ‘Ice-free in 2050 is a possible scenario, but I don’t think it is a likely scenario,’ she concluded.

    Seat-of-the-pants judgments with no scientific basis.

  10. Peer-reviewed research suggests that at least until 2005, natural variability was responsible for half the ice decline.
    ===============
    whenever an estimate say “half” you know that the estimator doesn’t have a clue how much to attribute either way.

    they are simply ball-parking a guess. Knowing the answer is somewhere between 0% and 100%, they are taking an average and calling this the “correct” answer. knowing that no one can proven the right or wrong, because no one knows.

    • I’ll bite – they just forgot the error bars as is common in Climate Science – the real value is half plus or minus half.

  11. A scientific theory that predicts both an effect and its opposite, that Global Warming will cause ice to expand or shrink, has no value to society. It may well be correct, but as a theory it is worthless.

    Image that Newtons Law of Universal Gravitation predicted that things might fall to earth, or they might float away from earth, with no way to be certain which way they would go.

    What value would there be in any such theory? It is useless for doing any sort of planning or prediction. The same with Global Warming. If it can cause more or less ice, more of less rain, more or less warming, without any way to know which will actually happen, how can you apply the theory to get any value?

    All the theory is telling you is that you can’t use it to predict anything.

  12. Nuts!! At this rate they will rediscovery the sun and lagged, cyclical effects on temperature there.

    • That’s not nuts, it’s supremely cynical politics. It’s essential to keep grant funding streams open that you can dupe funders that what you are suggesting is novel and unknown, even if the truth is it was well known 50 years ago.

      It happens across plenty of specialisms in ‘science’, you know.

      Not quite what science loving journos tell you, but I didn’t learn it from them, I learned it at the coalface over 20 years.

  13. “Dr Hawkins said: ‘There is undoubtedly some natural variability on top of the long-term downwards trend caused by the overall warming. This variability has probably contributed somewhat to the post-2000 steep declining trend, although the human-caused component still dominates.’

    Like many scientists, Dr Hawkins said these natural processes may be cyclical. If and when they go into reverse, they will cool, not warm, the Arctic, in which case, he said, ‘a decade with no declining trend’ in ice cover would be ‘entirely plausible’. ”

    Really the decline in sea ice accelerated from when the AMO shifted to its warm mode from 1995. And increased GHG forcing in theory increases positive AO/NAO conditions, while a warm AMO mode is associated with increases in negative AO/NAO conditions. So the theoretical human-caused component should be cooling the Arctic and not warming it.

    I suggest that the warm AMO mode is a wind driven amplified negative feedback to declines in solar forcing, and will have a renewed warming from around 2015 to 2025, out of phase with the sunspot cycles:

    http://www.woodfortrees.org/plot/esrl-amo/mean:25/normalise/plot/sidc-ssn/from:1855/normalise

  14. Lot is written about the AMO, but far less understood.
    I’ve just had a quick look at the Stykkisholmur data’s spectral composition:
    It shows no 60 year cycle.
    Principal periods are those of the Earth’s magnetic field, astronomical LOD, .ENSO and the Indian monsoon.

  15. Thanks, Paul. I think you are correct. And the evidence is in the public domain:
    See: Physical Oceanography Division – Frequently Asked Questions – Atlantic Multidecadal Oscillation (Atlantic Oceanographic & Meteorological Laboratory of NOAA)

    http://www.aoml.noaa.gov/phod/faq/amo_faq.php

    See: An Introduction To ENSO, AMO, and PDO – Part 2 (Bob Tisdale, Climate Observations. August 16, 2010)

    http://bobtisdale.wordpress.com/2010/08/16/an-introduction-to-enso-amo-and-pdo-part-2/

  16. Paul, have you back checked these for homogenizing, algorithms, adjustments? You know GISS and their adjustments……here today, gone tomorrow

  17. Jeez, figure 1 states “The confidence is very low for the years before 1830 and the values are preliminary and should not be referenced” — but that didn’t stop them from using those years to calculate & display the linear trend on that very chart!! It’s a self-parody!

  18. It just suddenly made sense to me that an obvious reason that proponents behind the AGW “theory” want to hurry up an pass world wide “laws”, including “carbon tax” is that when it turns colder the demand for carbon based fuels will go through the roof, thus not only making then HUGE profits but also giving them tremendous control over the population on the world.

    This seems to be very much like what a magician relies on. Keep people fretting about appearances while he moving his assets around under their very noses.

  19. > Like many scientists, Dr Hawkins said these natural
    > processes may be cyclical. If and when they go into
    > reverse, they will cool, not warm, the Arctic, in which
    > case, he said, ‘a decade with no declining trend’ in
    > ice cover would be ‘entirely plausible’.

    Wait for it… 5… 4… 3… 2… 1… Yes folks, “The Pause” in Arctic ice decline!

    On a more serious note, IARC JAXA’s value for Aug 31 is 5,218,262 km^2, which is actually UP 2730 km^2 over the 30th.This is the 13th year of IARC-JAXA data at http://www.ijis.iarc.uaf.edu/seaice/extent/plot_v2.csv

    2014’s numbers are right in the middle of the pack; 6 years are lower, and 6 years are higher. I’d be very surprised if August 30th’s number was the min for the year. The min usually comes around September 15th to 20th.

  20. If the AMO is a significant influence on natural variations of climate, we should not forget the last century saw TWO 30 year periods of upward trends in AMO and only ONE period of cooling.
    This century will see TWO periods of cooling and only ONE period of warming.

  21. I remember reading once that the Chinese were believed to have sailed to the N Pole in medieval times. Is that just a myth?

  22. I love that any cooling is cyclical, any warming man-made. So enshrined is their model worship religion that they don’t ever question whether warming could also be cyclical… Their faith compels them.

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