From the EUROPEAN GEOSCIENCES UNION
Antarctic explorers help make discovery — 100 years after their epic adventures
Heroes of Antarctic exploration have played a crucial role in research that suggests the area of sea ice around Antarctica has barely changed in size in 100 years.
Ice observations recorded in the ships’ logbooks of explorers such as the British Captain Robert Scott and Ernest Shackleton and the German Erich von Drygalski have been used to compare where the Antarctic ice edge was during the Heroic Age of Antarctic Exploration (1897-1917) and where satellites show it is today.
The study, published in the European Geosciences Union journal The Cryosphere, suggests Antarctic sea ice is much less sensitive to the effects of climate change than that of the Arctic, which in stark contrast has experienced a dramatic decline during the 20th century.
The research, by climate scientists at the University of Reading, estimates the extent of Antarctic summer sea ice is at most 14% smaller now than during the early 1900s.
Jonathan Day, who led the study, said: “The missions of Scott and Shackleton are remembered in history as heroic failures, yet the data collected by these and other explorers could profoundly change the way we view the ebb and flow of Antarctic sea ice.
“We know that sea ice in the Antarctic has increased slightly over the past 30 years, since satellite observations began. Scientists have been grappling to understand this trend in the context of global warming, but these new findings suggest it may not be anything new.
“If ice levels were as low a century ago as estimated in this research, then a similar increase may have occurred between then and the middle of the century, when previous studies suggest ice levels were far higher.”
The new study published in The Cryosphere is the first to shed light on sea ice extent in the period prior to the 1930s, and suggests the levels in the early 1900s were in fact similar to today, at between 5.3 and 7.4 million square kilometres. Although one region, the Weddell Sea, did have a significantly larger ice cover.
Published estimates suggest Antarctic sea ice extent was significantly higher during the 1950s, before a steep decline returned it to around 6 million square kilometres in recent decades.
The research suggests that the climate of Antarctica may have fluctuated significantly throughout the 20th century, swinging between decades of high ice cover and decades of low ice cover, rather than enduring a steady downward trend.
This study builds on international efforts to recover old weather and climate data from ships’ logbooks. The public can volunteer to rescue more data at oldweather.org.
Day said: “The Southern Ocean is largely a ‘black hole’ as far as historical climate change data is concerned, but future activities planned to recover data from naval and whaling ships will help us to understand past climate variations and what to expect in the future.”
Capt Scott perished along with his team in 1912 after missing out on being the first to reach the South Pole by a matter of weeks, while Shackleton’s ship sank after becoming trapped in ice in 1915 as he and his crew journeyed to attempt the first ever cross-Antarctic trek.
In addition to using ship logbooks from three expeditions led by Scott and two by Shackleton, the researchers used sea-ice records from Belgian, German and French missions, among others. But the team was unable to analyse some logbooks from the Heroic Age period, which have not yet been imaged and digitised. These include the records from the Norwegian Antarctic expedition of 1910-12 lead by Roald Amundsen, the first person to reach both the south and north poles.
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Here is the link to the paper
Melting Arctic sea ice precedes an Ice Age. http://harpers.org/archive/1958/09/the-coming-ice-age/
The NH has the AMOC and Gulf Stream. These are driven by the salinity-downwelling positive feedback. The Gulf Stream brings high salinity water to the North Atlantic. When it cools its higher salinity makes it downwell cold dense water to the ocean floor – deep water formation in the Norwegian Sea. This deep cold dense water flows south, completing the loop of the AMOC. By doing so it in turn propels the northward Gulf Stream up on the surface, reinforcing the whole circuit with positive feedback.
In the paradigm of current climate science this positive feedback at the heart of the AMOC would be assumed to be runaway and would soon be expected (projected) to turn the Atlantic Ocean into a whirling maelstrom like a washing machine. However in the real world of complex systems positive feedback does not do this, instead it causes oscillation and intermittency. Each “run” of the positive feedback causes eventually a negative feedback, which cuts it off. In the North Atlantic the negative feedback that cuts off the Gulf and cold downwelling feedback – which warms the Atlantic high latitudes – is Greenland ice melt and a resulting freshwater pulse, which chokes off the cold water formation and downwelling.
Thus chaotic oscillations in complex natural systems are driven by a mix of positive and negative feedbacks. The consequence of this chaotic instability in the AMOC is that the NH climate tends to oscillate, with the AMO and other related oceanic oscillations like the PDO.
But in the SH there is no such instability, there is no meridionally bounded ocean south of Africa and South America. In the Southern Ocean you have the unimpeded circumpolar circulation.
Thus there is contrasting behaviour of the climate in the NH, where it is unstable and oscillates, and the SH, where it is much more stable and changes over much longer timescales. This gives a reciprocating interpkay of climate change between the two hemispheres. Earth’s climate is chaotic and is always changing, such that the term “climate change” itself is unnecessary, redundant, tautological and meaningless.
This NH-SH interplay gives the phenomenon of the “bipolar seesaw” which operates on timescales of centuries and millennia. It provides a fully adequate null hypothesis for late 20th north hemisphere “climate change” – with the added bonus of explaining the contrasting near stasis or slight reciprocal changes in the SH. Thus CO2 induced warming, whether or not it is a significant factor, is wholly unnecessary for explaining what really requires almost no explanation – the permanent reality unstable and changing climate.
@ur momisugly Dave Fair 6:46pm “…with osculations in both the Pacific (PDO) and North Atlantic (AMO) oceans of undetermined origins.”
Kissing cousins the origins? Or did you mean oscillations?
I must have kissed my proof reader bye bye, David.
Most likely European Eurocrats will sequester the log books and any other files and films because as they will say, such is not understandable by the “American” mind.
This tactic was uses for many decades by Japanese Japanocrats to prevent “American” i.e. causasian scientists from conducting research, like geology and geophysics, in Japan.
The usual verbiage from the Superior Japanocrat goes like, “Foolish ‘American’ you think you can understand … Japan. How Stupid. How Foolish. Foolish ‘American’! Japan is Special. Japan is beyond your foolish mind! Stupid ‘American”. Play your stupid games in stupid ‘California’!”
Neither the Arctic seems to have changed: http://www.thegwpf.com/accounts-from-19th-century-canadian-arctic-explorers-logs-reflect-present-climate-conditions/
That Antarctic is less sensitive to “climate change” makes physical sense, as the circumpolar flow of the surrounding waters decreases the intrusion of warmer waters, a situation which does not exist for the Arctic.
..If I understand correctly, if there is ice at the poles, then we are still in an Ice Age…WHY do we worry about ice at the poles ? Why do we want to be stuck in an Ice Age ? As a disabled American/Canadian, I do not want to see more ice…I have tried to look for the benefits of more ice around the world, and I just cannot find any !!..IMHO
There is no benefit from more ice – but the consequences on weather systems of no ice or almost none will be severe… how could they not be?
This article summarises some – yes its exaggerated because its a journalistic summary of the research, but go look at the research…
http://www.independent.co.uk/environment/arctic-sea-ice-melting-polar-north-antarctic-global-warming-climate-change-tipping-point-a7438416.html
Griff
Has it ever crossed your mind to look at past ages such as the Mesozoic when global climate was around 10 degrees warmer than now? This is of course out of bounds for your CAGW hymn-sheet / mind manacles.
According to AGW paradigm a Mesozoic world 10 degrees warmer than now would have 100% desert throughout the tropical belt. But needless to say this is nonsense. As climate warms the tropics do not warm. It’s just that warm climates extend further poleward- eventually as far as the poles.
The Mesozoic was the high point of life on earth with unparalleled fecundity and vigorour of the biosphere as a whole.
The AGW belief in uniform global warming simply shows that it is politically driven and there is zero understanding and even less interest in the actual science of climate.
“ptolemy2 November 27, 2016 at 4:26 am”
You are asking Griff to explore records that extend way past the 2 minute soundbite he is used to.
Well a similar exercise from arctic data – not only explorer data, but soviet era records, weather records, ships logs, cold war submarine logs from under the ice and whaling records – in short all available sources – conclude that the arctic sea ice is at its lowest for 150 years…
Here’s an article summarising that research – if you are sensitive about source material, note it links to the original research. It has some nice old maps too.
https://www.carbonbrief.org/guest-post-piecing-together-arctic-sea-ice-history-1850
so, if you are going to argue the Antarctic ice has now been shown to be the same as in the 1900s, you are arguing the arctic ice is at a 150 year low…
Keep digging Griff, keep digging, soon you won’t be able to climb your way out.
Mean while old ships logs http://m.phys.org/news/2016-11-captain-cook-global-today-arctic.html from the Arctic confirm global warming. We all know that the Antarctic behaves in mysterious ways contrary to what the rest of the warming globe does.
Just to show how hard it is to hammer the facts into the thick, green crania, this article just appeared on my newsfeed:
Past glacier movements offer clues to the future of ice melt
http://www.pbs.org/newshour/rundown/glacier-movements-ice-melt/
Opening lines from general all-rounder and definite non-science-literate Julia Griffin:
“The West Antarctic ice sheet holds enough water to raise the world’s oceans an estimated 10 feet, and it’s shrinking. ”
And the great unwashed will simply believe it … abandon all hope. 🙁