by Michael Stars et al., June 5, 2017 in Nature Communication
High latitude ocean gateway changes are thought to play a key role in Cenozoic climate evolution. However, the underlying ocean dynamics are poorly understood. Here we use a fully coupled atmosphere-ocean model to investigate the effect of ocean gateway formation that is associated with the subsidence of the Greenland–Scotland Ridge. We find a threshold in sill depth (∼50 m) that is linked to the influence of wind mixing.
by Paul Homewood, June 5, 2017
Arctic sea ice extent continues to run well above the level of the last two years.
Much more significantly though, the average extent for the whole of May was the highest since 2013, and was also higher than 2004 and 2006.
by Hiroki Tokinaga et al., PNAS, May 1, 2017
Arctic amplification is a robust feature of climate response to global warming, with large impacts on ecosystems and societies. A long-standing mystery is that a pronounced Arctic warming occurred during the early 20th century when the rate of interdecadal change in radiative forcing was much weaker than at present. Here, using observations and model experiments, we show that the combined effect of internally generated Pacific and Atlantic interdecadal variabilities intensified the Arctic land warming in the early 20th century.
by Randall Hayman, May 8, 2017, in Science
Good news about climate change is especially rare in the Arctic. But now comes news that increases in one greenhouse gas—methane—lead to the dramatic decline of another. Research off the coast of Norway’s Svalbard archipelago suggests that where methane gas bubbles up from seafloor seeps, surface waters directly above absorb twice as much carbon dioxide (CO2) as surrounding waters. The findings suggest that methane seeps in isolated spots in the Arctic could lessen the impact of climate change.
by Dr. John D. Harper, FGSA,FGAC, PGeol., former director of the Geological Survey of Canada © May 2017
I have recently been asked to comment on three articles published in The Economist. My background for such a response is as a Professor of Petroleum Geology and Sedimentology (ret.), a former Director-Energy for the Geological Survey of Canada, a former researcher in industry, and as an academic researcher on sea level changes and climate documentation through geologic time, Natural Resources of the Future and a couple of decades of studies in the Arctic.
1) Skating on thin ice: The thawing Arctic threatens an environmental catastrophe. Apr 27, 2017
2) The Arctic as it is known today is almost certainly gone. April 29, 2017
3) Thaw point: As the Arctic melts the world’s weather suffers. April 29, 2017
by Geological Society of America, April 13, 2017
Cretaceous climate warming led to a significant methane release from the seafloor, indicating potential for similar destabilization of gas hydrates under modern global warming. A field campaign on the remote Ellef Ringnes Island, Canadian High Arctic, discovered an astounding number of methane seep mounds in Cretaceous age sediments.
by Q. Ding et al., March 13, 2017, Nature Climate Change
The Arctic has seen rapid sea-ice decline in the past three decades, whilst warming at about twice the global average rate. Yet the relationship between Arctic warming and sea-ice loss is not well understood. Here, we present evidence that trends in summertime atmospheric circulation may have contributed as much as 60% to the September sea-ice extent decline since 1979.
Egalement : Recul de la banquise arctique: 30% à 50% lié à la variabilité naturelle de l’atmosphère
by Paul Homewood, April 6, 2017
DMI have now published the Arctic sea ice extents for March. The average this year was 14.71 million sq km, exactly the same as 2015, and only 60,000sq km less than in 2006.
by Dr. Sebastian Lüning and Prof. Fritz Vahrenholt [German text translated/edited by P Gosselin] , April 1, 2017
Now let’s extend the time scale and look back 100 years. What a surprise: In the 1930s and 1940s there were two heat decades in the Arctic which were almost as warm as today (Fig. 2). This is just a small fact that went missing in the WMO press release and in the derwesten.de article.