Tuesday 13 August 2013

Climate change news

Cyclone raging on Thin Ice
12 August, 2013
Another cyclone is raging over the Arctic Ocean. The Naval Research Laboratory image below shows the speed and drift of the sea ice.

[ click on image to enlarge ]

Last time a cyclone hit the Arctic, this resulted in a temporary increase in area covered by sea ice, as shown on the Cryosphere Today image below. The cyclone pushed down on the sea ice, flattening it and pushing it sideways. 


Note that area as measured by the Cryosphere Today includes all spots that have a 15% or higher concentration of ice. This way of measuring area ignores the fact that the cyclone reduced the sea ice concentration in many spots, from a high sea ice concentration (around 90%) to a lower concentration (less than 80%), as shown on the Naval Research Laboratory image below. 


Furthermore, sea ice has since dropped in thickness, as illustrated by the Naval Research Laboratory image below. 


Much of the ice is now less than one meter thick, while some areas close to the North Pole have ice that is only between zero and half a meter thick.

The cyclone is raging most fiercely in those areas and much of the ice is drifting out into the Atlantic Ocean.

Neven mentioned at the 
Arctic Sea Ice Blog that average thickness (crudely calculated by dividing PIOMAS (PI) volume numbers with Cryosphere Today (CT) sea ice area numbers, see image below) had a very steep drop in July, similar to the drop in 2010. This year's trend line is now lowest, probably signifying that the ice pack is spread out and thin at the edges (read: melting potential).


The image below, from the University of Bremen, Germany, shows sea ice concentration on August 11, 2013.





More on Wildfires

12 August, 2013

Previous posts have highlighted the huge amounts of carbon dioxide, methane and soot being emitted as a result of wildfires. Apart from this, there are further important pollutants to consider in regard to their potential to contribute to warming, especially at high latitudes.

The image below, dated August 7, 2013, and kindly supplied by Leonid Yurganov, shows high levels of carbon monoxide as a result of wildfires in Siberia, reaching high up into the Arctic all the way to Greenland. 



Formation of tropospheric ozone mostly occurs when nitrogen oxides (NOx), carbon monoxide (CO) and volatile organic compounds (VOCs) react in the atmosphere in the presence of sunlight. NOx, CO, and VOCs are therefore called ozone precursors. Apart from a health hazard, tropospheric ozone is an important greenhouse gas. Furthermore, carbon dioxide emissions contribute to hydroxyl depletion, thus extending the lifetime of methane.

While there appears to be little or no carbon dioxide from wildfires over North America on the above Augsut 7 image, there are many recent wildfires raging over the North American continent, as illustrated by the August 12 map below, from Wunderground






Methane levels remain very high around the globe


9 August, 2013


The image below shows methane levels over 1950 in yellow for both hemispheres, on the morning of August 8, 2013.

[ click on image to enlarge ]


The highest peak recorded was 2428 ppb at 367 mb. The highest mean was 1822 ppb at 469 mb. See also the image below for an overview of recent methane levels.


The situation is very worrying, especially since there's a huge amount of methane in the northern part of Asia and Europe, much of it bordering on the Arctic. This methane will trap a lot of heat there at a time when the melting season is still going strong. 

On the Southern Hemisphere, there's a huge amount of methane recorded over Antarctica. That has been going on for quite some time, but the high levels of methane over the oceans on the Southern Hemisphere have only shown up recently. They could be caused by one or more methane hydrates getting destabilized in the ocean between Antarctica and South America.




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