Sunday, 29 January 2017

More Arctic Ocean feedbacks

Arctic Ocean Feedbacks


27 January, 2017


The world's oceans are warming rapidly, and especially the Arctic. In December 2016, the temperature anomaly from latitude 83°N to the North Pole was 8 times as high as the global anomaly. The Arctic Ocean is warming particularly rapidly due to a multitude of feedbacks, some of which are illustrated on the image below.


As the Arctic is warming more rapidly than the rest of the world, the temperature difference between the Arctic and the northern latitudes decreases, which makes the jet stream wavier. Jennifer Francis has 
written extensively about jet stream changes as a result of rapid warming in the Arctic. In the video below, Peter Sinclair interviews Jennifer Francis on these changes.



The changes to the jet stream make it easier for warm air from the south to enter the Arctic and for cold air to move out of the Arctic deep down into North America and Eurasia. At the same time, this also increases the temperature difference between the continents and the oceans, which is quite significant given the rapid warming of oceans across the globe. The result of the greater temperature difference between oceans and continents is that stronger winds are now flowing over the oceans along the jet stream tracks.

Stronger winds come with more evaporation and rain, which accumulates as freshwater at the surface of the North Atlantic and the North Pacific. The freshwater acts as a seal, as a lid on the ocean, making that less heat gets transferred from underneath the freshwater lid to the atmosphere. This makes that more heat can travel underneath the sea surface through the North Atlantic and reach the Arctic Ocean.





The situation is illustrated by above image, showing areas over the North Atlantic and the North Pacific (blue) where the sea surface was colder than it was in 1981-2011 on January 27, 2017. Over these colder areas, winds are stronger due to the changes to the jet stream. At the same time, temperature anomalies as high as 18°C (or 32.4°F) are showing up off the coast of Japan, and anomalies as high as 10.9°C (or 19.5°F) are showing up near Svalbard in the Arctic.

The image on the right shows sea surface temperature anomalies from 1971-2000.

The 
video below shows precipitation over the Arctic, run on January 27, 2017, and valid up to February 4, 2017.



The changes to the jet stream and the associated changes discussed in this post all lead to further warming of the Arctic Ocean, next to the warming caused by other feedbacks such as loss of albedo and loss of ice as a heat buffer. Together, these feedbacks could cause global temperatures to rise by 1.6°C by 2026.

There are further feedbacks affecting the Arctic, as described at 
this page. Perhaps the most dangerous feedback is methane escaping from the seafloor of the Arctic Ocean. As the temperature of the Arctic Ocean keeps rising, it seems inevitable that more and more methane will rise from its seafloor and enter the atmosphere, at first strongly warming up the atmosphere over the Arctic Ocean itself - thus causing further methane eruptions - and eventually warming up the atmosphere across the globe.

Feedbacks and further elements of a potential temperature rise by 2026 of more than 10°C above prehistoric levels are further described at the 
extinction page.

The situation is dire and calls for comprehensive and effective action as described in the 
Climate Plan.


Links

• Climate Plan
http://arctic-news.blogspot.com/p/climateplan.html

• Feedbacks
http://arctic-news.blogspot.com/p/feedbacks.html

• Extinction
http://arctic-news.blogspot.com/p/extinction.html

• 2016 well above 1.5°C
http://arctic-news.blogspot.com/2017/01/2016-well-above-1.5c.html

• Accelerating Warming of the Arctic Ocean

http://arctic-news.blogspot.com/2016/12/accelerating-warming-of-the-arctic-ocean.html


No comments:

Post a Comment