Showing posts with label East Siberian Arctic Shelf. Show all posts
Showing posts with label East Siberian Arctic Shelf. Show all posts

Sunday, November 2, 2014

Methane Erupting From East Siberian Arctic Shelf

Methane is erupting in huge amounts from the seafloor of the Arctic Ocean, as illustrated by the images below, showing methane over the East Siberian Arctic Shelf on October 31, 2014.

The top image on the right shows methane at an altitude of 19,820 feet (6,041 m), on October 31, 2014, pm, as captured by the MetOp1 satellite.

The middle image shows the location of the seas north of Siberia, and shows methane over the Arctic Ocean close to sea level, for reference.

The bottom image is an animation, starting at an altitude close to sea level and rising over 25 frames to an altitude of 19,820 feet (6,041 m).

As altitude increases, the methane can be seen emerging from the Laptev Sea at first, then spreading over further parts of the Arctic Ocean.

The yellow color indicates that methane is present at levels of 1950 ppb or higher.

High CO2 levels over Arctic Ocean

As in the previous post, an image has been added (below) showing recent carbon dioxide levels. Close to ground level (or rather sea level), mean CO2 level increased to 402 ppm on November 1, 2014 am, as measured by the MetOp-1 satellite.


The image below shows a comparison between CO2 (left) and methane (right).

[ Image added later, Ed. Click on image to enlarge ]
Above images indicate that large amounts of methane are broken down at higher latitudes on the Northern Hemisphere, especially over the Arctic Ocean.

Large methane eruptions from the seafloor of Arctic Ocean continue

The two images below [added later, ed.] further confirm the huge size of the methane erupting from the seafloor of the Arctic Ocean. The image directly below shows that levels as high as 2362 ppb were recorded on November 5, 2014 p.m.by the MetOp-1 satellite at an altitude of 14,385 ft (4,384 m) altitude. The image also shows that the methane is predominantly visible over the Arctic Ocean, further confirming that this is indeed the cause of the continued high methane levels.


The recent methane eruptions from the seafloor of the Arctic Ocean also appear to be pushing up methane levels at Mauna Loa, Hawaii, as measured by NOAA on November 6, 2014, as illustrated by the combination image below showing daily averages (left) and hourly averages (right).


Methane eruptions from Arctic Ocean seafloor look set to continue for months to come

As oceans keep warming, the Gulf Stream
will keep moving ocean heat into the Arctic Ocean, and ever more methane threatens to erupt from the seafloor of the Arctic Ocean.

The image on the right shows the huge sea surface temperature anomalies off the coast of North America and in the Arctic. Heat in the North Atlantic will take some time to travel to the Arctic Ocean, so this heat has yet to arrive there and contribute to cause further methane eruptions.

Nations are ignoring the growing dangers and keep each seeking a bigger share of a 'carbon budget', but in reality there is no carbon budget to divide. Instead, there is a huge debt built up by a joint failure of nations to act on pollution.

Increased methane eruptions from the seafloor of the Arctic Ocean threaten to further accelerate warming in the Arctic, in turn resulting in ever more methane being released, as illustrated in the image below, from an earlier post.

Methane in historic perspective

The image below shows that global methane levels have risen from 723 ppb in 1755 to 1839 ppb in 2014, a rise of more than 254%. Growth did flatten down for a few years in the early 2000s, but the overall rise does not appear to slow down.

The right-end of this graph is shown in greater detail on the image below, which also has a trendline extended to the year 2021, against a background of methane levels measured by the MetOp-1 satellite on November 2, 2014, p.m.

Note that the image used as background in the plot area has different axis labels, i.e. latitude for the vertical axis and longitude for the horizontal axis. The image below gives the levels associated with the colors on the background image, with yellow indicating levels of 1950 parts per billion (ppb) and higher.


Remember that the level of 723 ppb in 1755 was not a paleo-historic low, but instead was the high peak of a Milankovitch Cycle. The image below further illustrates this point.


And so does the image below, by Reg Morrison.


Comprehensive and effective action needed

The situation is dire and calls for comprehensive and effective action. The Climate Plan seeks emission cuts, removal of pollution from soils, oceans and atmosphere, and further action, as illustrated by the image below, from an earlier post.




Sunday, November 24, 2013

Quantifying Arctic Methane

The paper 'Ebullition and storm-induced methane release from the East Siberian Arctic Shelf', was published in the journal Nature Geoscience on November 24, 2013.

The paper is dedicated “to the memory of the crew of Russian vessel RV Alexei Kulakovsky”, the 11 people who died when their tugboat perished in efforts to assist the scientists who were measuring methane from a fishing boat.

The research team used methods including drilling into the seabed of the Laptev Sea and sonar to analyse methane releases in the water, seeking to quantify the significant amounts of methane that are bubbling up from the sea bed in the East Siberian Arctic Shelf (ESAS, rectangle on image below), the area with shallow seas north of Siberia covering some 810,800 square miles (2.1 million square kilometers). By comparison, the United States (land and water) covers an area of nearly 10 million square kilometers.

“We have proven that the current state of subsea permafrost is incomparably closer to the thaw point than terrestrial permafrost, and that modern warming does contribute to warming the subsea permafrost,” says Natalia Shakhova, adding that an increase in storminess in the Arctic would further speed up the release of methane.

The scientists estimate, on the basis of the sonar data, that “bubbles escaping the partially thawed permafrost inject 100–630 mg methane square meters daily into the overlying water column”, and suggest that “bubbles and storms facilitate the flux of this methane to the overlying ocean and atmosphere, respectively”.

Some 17 teragrams (Tg or Mt) of methane escapes annually from the ESAS, said Natalia Shakova, lead study author and a biogeochemist at the University of Alaska, Fairbanks. This is an upgrade from the earlier estimate of 8 Tg of annual outgassing from the ESAS (Shakhova et al. 2010).

While including a reference to this earlier paper (Shakhova et al. 2010), the IPCC did give much lower estimates for emissions from all hydrates globally and from permafrost (excl. lakes and wetlands), i.e. 6 and 1 Tg per year, respectively.

And by comparison, IPCC estimates for all global methane emissions from manmade and natural sources go from 526 Tg per year to 852 Tg per year, of which 514 to 785 Tg per year is broken down (mostly by hydroxyl).

Sadly, as discussed in an earlier post, the IPCC has decided NOT to warn people about the danger that methane from hydrates will lead to abrupt climate change within decades. Yet, when entering the data by Shakhova et al. in a spreadsheet, a linear trendline (green line on image below) shows methane release in the ESAS reaching 20 Tg by 2013 and 26 Tg by 2015.


An exponential trendline (red/blue line) shows methane release in the ESAS reaching 22 Tg by 2013 and 36 Tg by 2015. Extending that same exponential trendline further into the future shows methane release in the ESAS reaching 2 Gt by the year 2031 and 50 Gt by the year 2043.


Note that accumulated totals over the years will be much higher than the annual release. While the IPCC gives methane a perturbation lifetime of 12.4 years, this methane will persist in the Arctic for much longer because its release is concentrated in the Arctic where hydroxyl levels are also very low.

Globally, IPCC/NOAA figures suggest that abundance of methane in the atmosphere currently (2013) is 1814 parts per billion (ppb), rising with 5 or 6 ppb annually, and that this rise is caused by a difference of 8 Tg between the methane emitted (548 Tg, top-down estimate) and broken down annually (540 Tg, top-down estimate). It is also worth noting that the IPCC has increased methane's global warming potential to 86 over 20 years with climate-carbon feedbacks, while there are reasons to assume that methane's impact, especially short-term and in case of large abrupt releases in the Arctic, is even stronger. Furthermore, the IPCC now gives methane a Radiative Forcing (RF) of 0.97 W/m-2 (up from 48 W/m-2 in 2007 and relative to 1750), as illustrated by the image below.


According to the IPCC, methane levels in 1750 and 2011 were 722 ppb and 1803 ppb, respectively. The total global methane burden is estimated to be about 5 Gt, i.e. 5 petagrams (Pg) or 5,000 Tg. A back-of-envelope calculation sugests that the methane burden in 1750 was 5 Gt x (722 : 1803) = 2 Gt. Furthermore, methane's 0.97 W/m-2 RF is 42% of the total RF 2.29 W/m-2. Therefore, the 3 Gt of methane that has been added to the atmosphere since 1750 is responsible for almost half of all the global warming since that time.

For now, the IPCC's estimated annual increase in global methane levels may seem small, but this figure appears to be based on low-altitude data collected over the past few decades. The total methane burden may already be rising much more rapidly, also because methane is rising in the atmosphere, increasing the burden especially at higher altitudes, as evidenced by the increasing occurence of noctilucent clouds. In other words, the 8 Tg estimate may reflect older data related to changes in lower-altitude measurements only, but the total methane burden may well be rising much more rapidly due to increases at higher altitudes. Further analysis comparing satellite data at different altitudes over the years could verify this.

An earlier post estimated that as much as 2.1 Mt (or 2.1 Tg) of methane could have been released abruptly end 2011. If you compare the animation of that earlier post with the recent animation, then current abrupt releases from the sea floor of the Arctic Ocean appear to be even higher.

As said, methane releases from the Arctic Ocean may for now seem small and may not yet make global temperatures rise much, but nonetheless the methane cloud hanging over the Arctic is contributing to warming locally. Combined with the increased likelyhood of extreme weather and rapid loss of ice and snow cover in the Arctic, this could make water temperatures in the Arctic Ocean rise even further, causing further destabilization of methane hydrates. Furthermore, the mechanical force of methane release from hydrates (rapidly expanding 160 times in volume) itself can also contribute to hydrate destabilization. Seismic activity could also lead to destabilization. Indeed, there are many factors that could contribute to exponential rise of methane release from the Arctic Ocean, as discussed in the post on methane hydrates, which calls for comprehensive and effective action, such as discussed at the Climate Plan blog.


References

Ebullition and storm-induced methane release from the East Siberian Arctic Shelf, by Natalia Shakhova, Igor Semiletov, Ira Leifer, Valentin Sergienko, Anatoly Salyuk, Denis Kosmach, Denis Chernykh, Chris Stubbs, Dmitry Nicolsky, Vladimir Tumskoy & Örjan Gustafsson (2013)
http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2007.html

Arctic storms speed up release of methane plumes, by Fred Pearce
http://www.newscientist.com/article/dn24639-arctic-storms-speed-up-release-of-methane-plumes.html

Twice as Much Methane Escaping Arctic Seafloor, by Becky Oskin
http://www.livescience.com/41476-more-arctic-seafloor-methane-found.html

Extensive methane venting to the atmosphere from sediments of the East Siberian Arctic shelf, by Natalia Shakhova, Igor Semiletov, Anatoly Salyuk, Vladimir Yusupov, Denis Kosmach, and Örjan Gustafsson, in: Science, 327, 1246-1250 (2010).
http://www.sciencemag.org/content/327/5970/1246.abstract

On carbon transport and fate in the East Siberian Arctic land–shelf–atmosphere system, by Semiletov et al. (2012)
http://iopscience.iop.org/1748-9326/7/1/015201

Intergovernmental Panel on Climate Change (IPCC), AR5 Working Group 1
http://www.climatechange2013.org/



Thursday, October 24, 2013

Epic Methane Releases from East Siberian Arctic Shelf

By Harold Hensel

[ click to enlarge ]

This is epic! Keep watching the Laptev and East Siberian Sea. This is a very dangerous place for methane to come up. Huge amounts of methane hydrates are stored below. They have been frozen there safely for over 10,000 years.

We are witnessing the thawing and large release of methane from this area for the first time in over 10,000 years. The fear is that at a critical point there may be a catastrophic sudden burst of methane from this area. This would more than likely trigger runaway global warming.

We could be watching the beginnings of this. If the red on the 1750 ppb and the yellow on the 1950 ppb setting on the methanetracker.org keeps spreading and intensifies, we are watching it happen. I hope this is an anomaly and these areas return to little or no activity.


Harold Hensel is at Facebook as facebook.com/mhhensel