Feedbacks in the Arctic

March 21, 2014     No comments
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This is more a climate report than a weather report; yet, the extreme weather that did hit the U.K. recently and that is forecast to hit large parts of North America next week may make more people realize that action is needed now. So, please share!

At the moment, a large part of Russia is experiencing temperature anomalies at the highest end of the scale, i.e. more than 36°F (20°C) warmer than average past records.

Above image shows the situation as at March 20, 2014. Over the past year, average temperatures over the Arctic Ocean have been much higher than they used to be, as illustrated by the NOAA image below.

[ compare the temperature anomaly for the Arctic Ocean in above image with the anomaly for the year 2013 ]

Temperatures over the Arctic Ocean are expected to rise even further next week. The Arctic as a whole is expected to reach average anomalies as high as 5.3°C next week, while many areas over the Arctic Ocean are expected to be hit by even higher anomalies, as the image below shows.

 [ click on image to enlarge ]

Above image also shows that, at the same time, very low temperatures – with anomalies at the low end of the scale – are expected to hit a large part of North America. The image below shows what temperatures can be expected on March 26, 2014, 12:00 UTC.

As above image illustrates, temperatures over a large part of North America can be expected to be hardly higher than temperatures over the Arctic Ocean mid next week. It is this very difference between high altitude temperatures and lower altitude temperatures that drives the Jet Stream. In the absence of much difference, changes to the Jet Stream changes are making it easier for cold air to move out of the Arctic and for warm air from lower latitudes to move in. The Polar Vortex is similarly affected, as illustrated by the image below.

At lower altitude, the highest wind speed detected on the image below was 94 km/h (green marker). Strong winds brought a lot of rain from the Atlantic Ocean to the U.K., as has been the case for some time.

[ click on image to enlarge ]
The result is more extreme weather, which can translate into more intense storms, heatwaves, droughts, wildfires and further havoc. Importantly, storms across the Arctic Ocean and higher wind speeds along the edges of Greenland can break up the ice and speed up its exit from the Arctic Ocean. The Naval Research Laboratory animation below shows strong winds pushing the sea ice around and speeding up its exit along the edges of Greenland.
Despite the cold weather that has hit large parts of North America over the past few months, the water off the coast of North America has not cooled, as illustrated by the image below. The blue and lilac colored areas are in part the result of exit currents carrying cold water out of the Arctic Ocean more rapidly, while the Gulf Stream continues to carry warmer water (brown and red colored areas) into the Arctic Ocean.
[ Sea Surface Temperatures (SST) – click on image to enlarge ]
The joint impact of such feedbacks becomes stronger as temperatures keep rising in the Arctic and with continued demise of the snow and ice cover. As weather becomes more extreme, stronger storms and heatwaves can be expected to hit the Arctic Ocean, and as snow and ice cover decline further, an ever larger part of the sunlight can be expected to be absorbed by the Arctic Ocean, rather than to be reflected back into space or be consumed in the process of transforming ice into water.
One of the most dangerous feedbacks is that, as the Arctic Ocean warms up further and as the Gulf Stream carries ever warmer water into the Arctic Ocean, methane can erupt from the seafloor of the Arctic Ocean in large quantities. This feedback has especially become noticable over the past half year.
Large methane releases are still entering the atmosphere over the Arctic Ocean, which contains very little hydroxyl to start with, so large abrupt releases will deplete the little hydroxyl that is there much faster than elsewhere. Furthermore, the methane will initially be highly concentrated in the atmosphere over the Arctic Ocean, and where the methane does move out of the Arctic, it could warm up the water along the track of the Gulf Stream, causing even warmer water to enter the Arctic Ocean. For years after its release, the methane will act as a powerful greenhouse gas. Unlike the albedo changes, which have the highest impact at the June Solstice when the amount of solar radiation received by the Arctic is higher than anywhere else on Earth, methane prevents heat from radiating out into space throughout the year.

Each of these feedbacks (extreme weather, methane release and albedo changes) can cause stronger temperature rises in this region than the rise resulting from carbon dioxide released in the atmosphere.

The interactive diagram below shows thirteen feedbacks that are accelerating warming in the Arctic, from the earlier post The Biggest Story of 2013.

Hover over each kind of warming and feedback to view more details, click to go to page with further background
Image Map emissions cause global warming Arctic warming accelerated by soot, etc. additional warming of Gulf Stream by emissions methane releases escalate Polar vortex and jet stream weaken as Arctic warms snow and ice decline causing less sunlight to be reflected back into space methane releases warm Arctic air as sea ice decline weakens vertical currents, seabed warms Storms cause vertical mixing of water accelerated Arctic warming causes storms that push cold air of the Arctic extreme weather causing storms that push away sea ice extreme weather causing storms that create higher waves, breaking up the sea ice storms creating more wavy waters that absorb more sunlight extreme weather causing fires, etc. weaker polar vortex and jet stream let cold air move out of Arctic extreme weather causing warmer waters snow and ice decline cause seismic activity that destabilizes hydrates methane releases prevent sea ice from forming

In conclusion, the situation is dire and calls for comprehensive and effective action, as described at the Climate Plan blog.

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