The image below covers a period of just over one day. On November 26, 2013, peak readings were as high as 2392 ppb.
The green circle highlights an area with high methane levels just north of Greenland. This methane likely originates from hydrates along the fault line that crosses the Arctic Ocean. As the Naval Research Laboratory animation below shows, sea ice in that area is rather thick. How it is possible for the methane to appear there? The answer must be, it seems, that there is so much movement in the sea ice in this area, that there are many cracks through which the methane can rise.
Above animation shows how a huge part of the sea ice, meters thick, is pushed along the edges of Greenland into the Atlantic Ocean, as a result of strong winds, as also illustrated by the animation below.
Methane has now been showing up prominently over the entire Arctic Ocean for more than a month and it doesn't look like this situation is coming to an end soon. The animation shows methane over the Arctic Ocean over a period of six days, with each frame covering a period of one day.
What is the impact of all this methane on temperatures over the Arctic? The NOAA image below shows surface temperature anomalies for a 30-day period.
When temperatures are averaged over longer periods, peaks will obviously show up less severe. Yet, on above image an area shows up in the Arctic where anomalies have averaged 15 degrees Celsius or more over this 30-day period.
When looking at individual days, anomalies of over 20 degrees Celsius can show up, on above image over quite a large area. While the weather can vary a lot and depends on a lot of factors, there is no doubt that the methane cloud hanging over the Arctic Ocean will have contributed to such anomalies. Since this methane isn't just going away soon, this spells bad news for what is ahead in the Arctic.
And while most efforts to contain global warming focus on ways to keep global temperature from rising with more than 2°C, a polynomial trendline already points at global temperature anomalies of 5°C by 2060. Even worse, a polynomial trend for the Arctic shows temperature anomalies of 4°C by 2020, 7°C by 2030 and 11°C by 2040, threatening to cause major feedbacks to kick in, including albedo changes and methane releases that will trigger runaway global warming that looks set to eventually catch up with accelerated warming in the Arctic and result in global temperature anomalies of 20°C+ by 2050.
Post by Sam Carana.
0 komentar:
Posting Komentar