Showing posts with label tundra. Show all posts
Showing posts with label tundra. Show all posts

Thursday, January 10, 2013

Dark Snow Project - Research into soot on Greenland

Fossil fuel combustion creates carbon emissions that increase atmospheric thickness, warming climate. The occurrence of wildfire increases with climate warming, increasing soot loading of the atmosphere. Some of this soot is transported through the atmosphere and is deposited on glaciers, lowering their reflectivity, increasing solar energy absorption, increasing melt rates.
image from DarkSnowProject.org

In parts of Greenland where winter snow loss during each melt season exposes impurity-rich bare ice, the surface reflectivity drops from 85% to 30%. Consequently, most of the 24-hour sunlight goes into ice melt. In this Dark Zone, the impact of soot manifests strongest in a self-reinforcing feedback loop that research by Jason Box has shown to have doubled melt rates in the past decade.

High on the inland ice sheet where melting is rare, satellite data show surface darkening making the researchers suspect that wildfire and industrial soot are to blame. Darkening here promotes snowpack heating, bringing earlier melt, keeping melt going longer. Here is where this feedback is changing the ice sheet in surprising ways, leading to complete surface melting in year 2012.



To measure the extent to which soot particles enhance melting, Jason Box is organizing a Greenland ice sheet expedition for 2013. The Dark Snow Project expedition is to be the first of its kind, made possible by crowd-source funding.



References

Fire and Ice: Wildfires Darkening Greenland Snowpack, Increasing Melting (News Release from Byrd Polar Center)
http://bprc.osu.edu/~jbox/DS/20121205_news_release_CALIPSO_etc.pdf

- The DarkSnowProject
http://darksnowproject.org

-Video: Sampling Greenland, the Dark Snow Project, by Peter Sinclair, produced at Greenman Studio, Midland, MI.
http://www.youtube.com/watch?v=vT6H7HPWkqU

- Where there’s fire there’s smoke - Blog by Jason Box, the Meltfactor.org


Further reading

- Greenland is melting at incredible rate
http://arctic-news.blogspot.com/2012/07/greenland-is-melting-at-incredible-rate.html

Sunday, September 23, 2012

Methane fields in the Laptev Sea

Below is part of a recent interview published by Voice of Russia - click here for the full report. Editorial note: We anxiously await further findings from the research team as to what the source is of these releases, when the methane was formed and by how much these releases are likely to increase over the years.


Methane emission in the Arctic – a possible key to the global warming

Maria Dunayeva
18.09.2012, 16:52
Russian scientists have discovered more than 200 sources of methane emissions in the Arctic, particularly in the north of the Laptev Sea. Two of the methane fields exceed 1 kilometer in diameter, said Igor Semiletov, expedition head aboard the Viktor Buinitsky research vessel. Methane emissions in the Arctic have been observed before and are explained by bacterial activity. Head of the ecology department at Moscow State University, Dmitry Zamolodchikov, spoke about the possible consequences in an exclusive interview with the Voice of Russia.
How would you comment on this discovery by Russian scientists?

Different examples of methane emissions in Arctic coastal regions and in the tundra systems have been observed over the last 20 or 30 years. There is really nothing surprising about this. Because, first of all, we are talking about frozen substances and cold conditions in the coastal area, in addition to the water pressure, all of which make perfect conditions for so called gas hydrates. That is a bond between methane and water, which looks like snow, and is fairly unstable. Gas hydrates can quite easily break and can cause, correspondingly, methane emissions. Methane emerges as a result of bacteria activity in an environment with little oxygen which decomposes organic substances. The tundra has a humid climate, meaning it has the perfect conditions for the methane-producing bacteria. In that sense tundra is the source of methane and these bacteria are active in this region. In other words the Arctic has many mechanisms for production of natural methane. There are many mechanisms that conserve methane, for example gas hydrates. Many of those mechanisms are broken at higher temperatures. Therefore, in some cases, mass emissions of methane can be observed.