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Showing posts with label hydrates. Show all posts
Showing posts with label hydrates. Show all posts

Tuesday, April 5, 2016

Record Arctic Warming

On April 3rd, 2016, Arctic sea ice extent was at a record low for the time of the year, reports the National Snow and Ice Data Center (NSIDC).

The image below, created with an image from the JAXA site, gives an update on sea ice extent.


Besides sea ice extent, sea ice area is important. For more on what constitutes "ice-covered" and what is sea ice extent (versus sea ice area), see this NSIDC FAQ page.

Another measure is sea ice area. On April 2nd, 2016, Northern Hemisphere sea ice area was at a record low for the time of the year, reports the Cryosphere Today.


In 2015, there still was more sea ice area than there is now when it was half a month later (15 days) into the year. In 2012, there still was more sea ice when it was 25 days later in the year. In other words, sea ice area decline is almost one month ahead compared with the situation in 2012.

NSIDC scientist Andrew Slater has created the chart below of freezing degree days in 2016 compared to other years at Latitude 80°N. See Andrew's website and this page for more on this.

The Arctic has warmed more than elsewhere on Earth. Surface temperatures over the past 365 days were more than 2.5°C or 4.5°F higher than they were in 1981-2010.


The image below compares sea ice thickness on April 3rd for the years 2012, 2015 and 2016 (respectively the left, center and right panel).


Sea ice thickness has fallen dramatically over the years, as illustrated by the image on the right, from NSIDC, showing Arctic sea ice age for the week from March 4 to 10, from 1985 to 2016.

The high temperatures that have hit the Arctic Ocean over the past 365 days make that the outlook for the sea ice in the Arctic this year is not good.

As illustrated by the image on the right, the current El Niño is still going strong, with temperatures above 100°F recorded in three continents.

The year 2016 is already shaping up as the warmest year on record by far.

Temperatures look set to soar over the coming months, over the Northern Hemisphere at large and over the Arctic in particular.

The image below shows that over a 90-day period from January 13, 2016, to April 11, 2016, most of the Arctic Ocean was more than 6°C (10.8°F) warmer than 1981-2011.

The DMI image below shows recent melting in Greenland up to April 11, 2016. Maps in the left panel show areas where melting has taken place on April 10 and April 11, 2016. The chart in the right panel shows 2016 melting (blue line), against the 1990-2013 average (the vertical axis reflects the percentage of the total area of the ice where the melting occurred).

As a recent study confirms, ice sheets can contain huge amounts of methane in the form of hydrates and free gas. Much methane can escape due to melting and fracturing during wild weather swings.


Rapid melting on Greenland looks set to continue. The forecast for April 12, 2016 (0000 UTC), on the right shows temperature anomalies at the top end of the scale (20°C or 36°F) over most of Greenland and Baffin Bay, while the Arctic as a whole is hit by a temperature anomaly of over 5°C (over 9°F), compared to 1979-2000.

Furthermore, ocean temperatures are currently very high. These high temperatures, together with the poor condition of the sea ice, make that chances are that the sea ice will be largely gone by September 2016.

[ click on images to enlarge them ]
The image on the bottom right shows sea surface temperature anomalies above Latitude 60°N on April 4, 2016.

The image below shows that, on April 7, 2016, sea surface in the Barents Sea was as warm as 10.1°C or 50.2°F, an anomaly of 9.4°C or 16.9°F from 1981-2011 (at the location marked by the top right green circle), while there were anomalies as high as 11.3°C or 20.3°F off the coast of North America (green circle bottom left).

The white line shows the approximate path of the cold exit current, while the red line shows the approximate path of the warm entry current.

The high temperatures in the Barents Sea give an indication of the ocean heat traveling toward the Arctic Ocean, while the high temperature anomalies off the east coast of North America give an indication of the heat that is building up there. Much of this heat will make its way to the Arctic Ocean over the coming months


April 11, 2016: SST anomalies as high as 11.6°C or 20.8°F
In the Pacific, sea surface temperature anomalies from 1981-2011 were as high as 11.6°C or 20.8°F near Japan on April 11, 2016 (see image right), giving a further indication of the huge amount of additional heat that there now is in oceans on the Northern Hemisphere. The prospect is that temperatures will rise over the next few months to levels even higher than they were last year (see earlier post on temperatures in June 2015).

Sea ice acts as a buffer, absorbing heat and keeping the temperature of the water at freezing point. Without such a buffer, further heat will instead make that the temperature of the water will rise rapidly. Furthermore, less sea ice means that less sunlight gets reflected back into space and more sunlight instead gets absorbed by the Arctic Ocean.

These are just some of the many feedbacks that accelerate warming in the Arctic. Warm water reaching the seafloor of the Arctic Ocean can penetrate sediments that can contain huge amounts of methane in the form of hydrates and free gas, triggering abrupt release of methane in gigantic quantities, escalating into runaway warming, and subsequent destruction and extinction at massive scale.

On a 10-year timescale, the current global release of methane from all anthropogenic sources already exceeds all anthropogenic carbon dioxide emissions as agents of global warming; that is, methane emissions are more important than carbon dioxide emissions for driving the current rate of global warming.


Above image shows that growth in methane levels has been accelerating recently; a trendline points at a doubling of methane levels by the year 2040. Unlike carbon dioxide, methane's GWP does rise as more of it is released. Methane's lifetime can be extended to decades, in particular due to depletion of hydroxyl in the atmosphere.

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

Albert Kallio comments: 
More could have been added from the last National Snow and Ice Data Center (NSIDC) Arctic sea ice report for March, the general outlook for massive sea ice loss because the near-all-time record low marine snow and ice cover is coinciding with near-all-time record low terrestrial snow cover. NSIDC forecast that due to dark surfaces being so high, this easily leads to loss of sea ice. In fact, 2016 situation is even worse that it was previous record loss 2012 when snow cover was much larger. Same in 2007 when the sea ice area was slighly smaller, there was much larger terrestrial snow cover. Furthermore, neither 2007 nor 2012 occurred during strong El Nino like 1998. El Nino 2015-2016 is the strongest ever, also accompanied by the very warm Indian Ocean, Atlantic Ocean, and Southern Ocean around Antarctica. At times Antarctic sea water temperatures were also high leading to second smallest Austral summer sea ice at one point. Sea ice area also around Antarctica has been smaller than average most of time, despite increased melt water and reduced salinity - due to high temperatures. All these additional factors should be added into your conclusions without forgetting to mention that the added heat in the earth system is ripping the Polar Vortex apart as the jet streams have started to blend into other irregular atmospheric wind patters. Note also the increased flow of sea ice through the Fram Strait due to lowered spatial viscosity of sea ice that also results from larger wave action, vertical mixing of ocean by wind, thinner sea ice breaking easier apart and collapsing into pack ice, as well as being mostly seasonal ice (containing trace amounts of salts that make the chemical bounds in ice crystals weaker and fragile and melting easier), May be you can update and rejoice on NSIDC's March 2016 report noting all the points therein..

On April 3rd, 2016, Arctic sea ice extent was at a record low for the time of the year, further confirming that the...
Posted by Sam Carana on Tuesday, April 5, 2016

Thursday, January 14, 2016

Greenhouse gas levels and temperatures keep rising

At the Paris Agreement, nations pledged to cut emissions and avoid dangerous temperature rises. Yet, the rise in greenhouse gas levels and temperatures appears to be accelerating.

Record growth of carbon dioxide levels at Mauna Loa

Annual mean carbon dioxide level measured at Mauna Loa, Hawaii, grew by 3.17 ppm (parts per million) in 2015, a higher growth rate than in any year since the record started in 1959.


As above image shows, a polynomial trendline added to the data points at a carbon dioxide growth rate of 4 ppm by the year 2024 and 5 ppm by the year 2028. 

At the start of the Industrial Revolution, the carbon dioxide level in the atmosphere was about 280 ppm. On January 11, 2016, as above image shows, carbon dioxide level at Mauna Loa, Hawaii, was 402.1 ppm. That's some 143% times what the upper level of carbon dioxide was in pre-industrial times over at least the past 400,000 years, as the image further below illustrates.

At higher northern latitudes, carbon dioxide levels are higher than elsewhere on Earth, as illustrated by above image. These high greenhouse gases contribute to accelerated warming of the Arctic. 

Methane levels rising even faster than CO2 levels, especially over Arctic Ocean

Historically, methane levels have been moving up and down between a window of 300 and 700 ppb. In modern times, methane levels have been rising even more rapidly than carbon dioxide levels, as illustrated by the image below, from an earlier post.

As above image illustrates, the mean level of 1839 ppb that was reached on September 7, 2014, is some 263% of the ~700 ppb that historically was methane's upper level.

The image below, from an earlier post, shows the available World Meteorological Organisation (WMO) annual means, i.e. from 1984 through to 2014, with added polynomial trendline based on these data. The square marks a high mean 2015 level, from NOAA's MetOp-2 satellite images, and it is added for comparison, so it does not influence the trendline, yet it does illustrate the direction of rise of methane levels and the threat that global mean methane levels will double well before the year 2040.


Recently, some very high peak levels have been recorded, including a reading of 2745 ppb on January 2, 2016, and a reading of 2963 ppb on January 8, 2016, shown below.



These high readings illustrate the danger that, as warmer water reaches the seafloor of the Arctic Ocean, it will increasingly destabilize sediments that can contain huge amounts of methane in the form of free gas and hydrates. Images associated with these high readings show the presence of high methane levels over the Arctic Ocean, indicating that these high peaks originate from the Arctic ocean and that sediments at the seafloor of the Arctic Ocean are destabilizing. The danger is that these peaks will be followed up by even stronger abrupt releases from the seafloor of the Arctic Ocean, as water temperatures keep rising.

Rising temperatures

Global mean temperature in 2015 was 0.87°C (~1.6°F) higher than in 1951-1980. 

Above image shows NASA data with a polynomial trendline added that points at a 2015 temperature that is more than 1.1°C (~2.03°F) higher than it was in 1900.

The image on the right shows that it was 1.17°C warmer in 2015 than it was in the period 1890-1910.

Additionally, some 0.3°C warming had already taken place by the year 1900, as discussed in an earlier post.

Together, that makes that 2015 temperatures were 1.47°C above pre-industrial levels.

Furthermore, temperatures did rise steeply over the course of the year 2015.

By the end of the year 2015, the temperature rise was even stronger than the average for 2015 would indicate, as illustrated by the image on the right.

It is now 2016 and temperatures are still rising. In other words, it now is more than 1.5°C or 2.7°F warmer than in pre-industrial times. In conclusion, we have already crossed the 1.5°C guardrail that the Paris Agreement had pledged to try and limit global warming to. 

What is the prognosis for the temperature rise from here onward? The current El Niño is expected to continue well into 2016. Even if the El Niño slows down, it will by then likely have contributed to huge losses of snow and ice cover, including sea ice melt in the Arctic. The resulting albedo changes alone may well have an even stronger warming effect than the El Niño, while there are further feedbacks such as disruption of the jet stream and methane eruptions from the seafloor of the Arctic Ocean.

The image below shows that, when that same trendline featuring in above graph is extended into the future, it points at a 2°C or 3.6°F global temperature anomaly rise before the year 2030, a rise of about 4°C or 7.2°F by 2040, and a 10°C or 18°F rise before the year 2060. That would be a rise compared to the period 1951-1980, i.e. warming compared to pre-industrial levels would be even more severe.


Three points are important to help more fully grasp the predicament we are in:
  1. At higher latitudes of the Northern Hemisphere, temperatures are rising faster than globally, as illustrated by above image that shows that a 10°C rise could hit the Arctic by 2030. 
  2. Summer peaks will be even more devastating than annual averages. 
  3. The rise of temperatures on land will be steeper than the rise in the combined land-ocean temperatures, as illustrated by the image below that shows that a 3°C rise on land could occur well before the year 2030.  


Comprehensive and effective action needed

As greenhouse gases and temperatures keep rising, the heat will be felt earliest and most severely on land, during the northern summer and in the Arctic.

One big danger is that soil that was previously frozen will become exposed and will start releasing huge amounts of carbon, in the form of carbon dioxide or methane.

Furthermore, boreal forest, tundra and peats bogs are at risk of firestorms that will also come with huge amounts of emissions.

All this will make the rise in temperature speed up even more, with much of the soot from firestorms in Siberia settling on the Himalaya Tibetan plateau, melting the glaciers there and causing short-term flooding followed by rapid decrease of the flow of ten of Asia’s largest river systems that originate there, with more than a billion people’s livelihoods depending on the continued flow of this water.

Again, the reason why temperatures look set to rise so abruptly and dramatically in the Arctic is feedbacks, as discussed as the feedbacks page. The biggest danger that comes with these rapidly rising temperatures in the Arctic is that large methane eruptions from the seafloor of the Arctic Ocean will further heat up the atmosphere, at first in hotspots over the Arctic, and eventually around the globe, while also causing huge temperature swings and extreme weather events, further contributing to increasing depletion of fresh water and food supply.

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

Below is an image by Malcolm Light, which updates an image that appeared in an earlier post




Annual mean carbon dioxide level measured at Mauna Loa, Hawaii, grew by 3.17 ppm (parts per million) in 2015, a higher...
Posted by Sam Carana on Thursday, January 14, 2016

Monday, December 28, 2015

2015 warmest year on record

1.1°C or 34.1°F at the North Pole
The year 2015 is shaping up to be the warmest year on record. In the media, a lot of attention has been given to the many floods, droughts, wildfires and heatwaves that have battered the world this year.

Sadly, though, little attention is given to the situation in the Arctic. The image on the right shows a forecast for December 30, 2015, with temperatures at the North Pole above freezing point, as further illustrated by the nullschool.net image below, showing a temperature forecast of 1.1°C or 34.1°F for the North Pole. Wind speed at the North Pole is forecast to be 105 mph or 168 km/h on December 30, 2015, and 133 mph or 215 km/h closer to Svalbard.


As the image below illustrates, very high temperatures are forecast to hit the Arctic Ocean on December 30, 2015.


Above image shows temperature anomalies at the highest end of the scale for most of the Arctic Ocean, with a temperature anomaly for the Arctic as a whole of 2.4°C or 4.32°F above what was common in 1979-2000. The situation isn't likely to improve soon. For January 3, 2016, the temperature in the Arctic is forecast to be as much as 4.56°C or 8.21°F warmer.

How is it possible for such high temperatures to occur over the Arctic Ocean? The image below shows how the year 2015 is shaping up in terms of temperature anomalies.


Global warming is felt most strongly in the Arctic as warming continues, as illustrated by above image and by the image on the right.

Warming in the Arctic is accelerating due to feedbacks. One of these feedbacks is the way the jet streams are changing. Changes in the jet streams are becoming more prominent as the Arctic is warming up more rapidly than the rest of the world.

jet streams
As the difference in temperature between the Arctic and the equator becomes smaller, the speed at which the jet stream circumnavigates the globe is decreasing and jet streams become more wavy.

Meanwhile, most of the extra heat caused by global warming goes into the oceans, and the Atlantic Ocean is warming up fast. At the same time, meltwater is accumulating at the surface of the North Atlantic, lowering sea surface temperatures there. With such large differences between high temperatures over North America and lower temperatures over the North Atlantic, the speed of the jet stream between those places can increase dramatically.

The result is that huge amounts of warm air are being pushed high into the Arctic. The image on the right shows the jet streams on December 27, 2015, when speeds as high as 263 mph or 424 km/h were reached at the location marked by the green circle. Also note the jet streams crossing the Arctic at the top of the image, while crossing the equator at the bottom of the image.

The image below shows sea surface temperature anomalies on the Northern Hemisphere in November.


For over a month now, storms over the North Atlantic have been pushing hot air high up into the Arctic. The video below uses surface wind content by Climate Reanalyzer (selected daily averages and sequences of forecasts) to cover the period from December 5, 2015, to January 8, 2016.



Best wishes for 2016
Above video stops at January 8, 2016, when two cyclones are visible, one in the North Atlantic and another one over the North Pacific, prompting me to create the image on the right.

What causes these storms to grow this strong? Waters keeps warming up dramatically off the east coast of North America. Emissions from North America tend to extend over these waters, due to the Coriolis effect, and this contributes to their extreme warming.

The image below shows carbon dioxide levels as high as 511 ppm over New York on November 5, 2015, and as high as 500 ppm over the water off the coast of coast of New Jersey on November 2, 2015. 


Emissions contribute to warmer waters - click to enlarge
The top panel of the image on the right shows that on December 11, 2015, carbon dioxide levels were as high as 474 ppm (parts per million, surface concentration) at the location marked by the green circle in New York.

The bottom panel of the image on the right shows that the water off the coast was warmer by as much as 10.3°C or 18.5°F at the location marked by the green circle on December 11, 2015.

The NASA video below shows carbon dioxide emissions over the year 2006.


It's not just CO2 off the North American coast that contributes to further warming of the Gulf Stream, many other emissions do so, including methane, CO, etc. Carbon monoxide (CO) is not a greenhouse gas, but it depletes hydroxyl, thus preventing oxidation of methane, a very potent greenhouse gas. The animation below shows a carbon monoxide level at green circle of 528 ppb on December 28, 2015, 0900z, while the sea surface temperature anomaly there was 15.8°F or 8.8°C on that day. 


Carbon monoxide reached much higher levels recently over land, as illustrated by the image below that shows a CO level of 2077 ppb in New York on January 6, 2016. 


These emissions heat up the Gulf Stream and make that ever warmer water is carried underneath the sea surface all the way into the Arctic Ocean, while little heat transfer occurs from ocean to atmosphere, due to the cold freshwater lid on the North Atlantic.

feedback #28 at the feedback page

The image on the right shows that it was warmer by as much as 9.6°C or 17.2°F near Svalbard on December 25, 2015, at the location marked by the green circle. The same anomalies were recorded on December 26, 2015, when the temperature of the water there was 11°C or 51.9 °F.

This gives an indication of how warm the water is that is being pushed underneath the sea surface into the Arctic Ocean.

Strong winds and high waves can cause more sea ice to be pushed along the edges of Greenland out of the Arctic Ocean, into the Atlantic ocean, expanding the cold freshwater lid on the North Atlantic, in a self-reinforcing feedback loop.

The image below shows the impact of these storms on sea ice speed and drift on December 31, 2015 (left) and a forecast for January 8, 2016 (right).


The danger is that, as warmer water reaches the seafloor of the Arctic Ocean, it will increasingly destabilize sediments that can contain huge amounts of methane in the form of free gas and hydrates.


Methane levels over the Arctic Ocean are already very high. Above image shows methane levels as high as 2745 ppb over the Arctic Ocean on January 2, 2016. High releases from the Arctic Ocean seafloor are pushing up methane levels higher in the atmosphere, as discussed in earlier posts such as this one.

So, while the extreme weather events that have occurred in the year 2015 are frightening, even more terrifying is the way the water of the Arctic Ocean is warming up. Sadly, this is rarely even discussed in the media. So, let's once more add the image below that should have been given more media attention.


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



The year 2015 is shaping up to be the warmest year on record. In the media, a lot of attention has been given to the...
Posted by Sam Carana on Monday, December 28, 2015

Friday, December 4, 2015

Ocean Heat Depth

Ocean heat at the equator


On November 24, 2015, equatorial waters at ≈100 m (328 ft) depth at 110-135°W were over 6°C (10.8°F) warmer than average in 1981-2000, as illustrated by above image. The animation below shows equatorial ocean heat over the past few months, illustrating that temperature anomalies greater than 6°C (10.8°F) occurred throughout this period at depths greater than 100 m (328 ft).

The danger of ocean heat destablizing clathrates in the Arctic

The danger is that ever warmer water will reach the seafloor of the Arctic Ocean and destabilize methane that is held there in sediments the form of free gas and hydrates.

So, how comparable is the situation at the equator with the situation in the Arctic? How much heating of the Arctic Ocean has taken place over the past few years?

The image on the right, produced with NOAA data, shows mean coastal sea surface temperatures of over 10°C (50°F) in some areas in the Arctic on August 22, 2007.

In shallow waters, heat can more easily reach the bottom of the sea. In 2007, strong polynya activity caused more summertime open water in the Laptev Sea, in turn causing more vertical mixing of the water column during storms in late 2007, according to this study, and bottom water temperatures on the mid-shelf increased by more than 3°C (5.4°F) compared to the long-term mean.

This study finds that drastic sea ice shrinkage causes increase in storm activities and deepening of the wind-wave-mixing layer down to depth ~50 m (164 ft) that enhance methane release from the water column to the atmosphere. Indeed, the danger is that heat will warm up sediments under the sea, containing methane in hydrates and as free gas, causing large amounts of this methane to escape rather abruptly into the atmosphere.

The image below, replotted by Leonid Yurganov from a study by Chepurin et al, shows sea water temperature at different depths in the Barents Sea, as described in an earlier post.


The image below is from a study published in Nature on November 24, 2013, showing water temperatures measurements taken in the Laptev Sea from 1999-2012.

Water temperatures in Laptev Sea. Red triangles: summer. Blue triangles: winter. Green squares: historic data.
From Shakhova et al., (2013) doi:10.1038/ngeo2007
Before drawing conclusions, let's examine some peculiarities of the Arctic Ocean more closely, specifically some special conditions in the Arctic that could lead to greater warming than elsewhere and feedbacks that could accelerate warming even more.

Amount of methane ready for release

Sediments underneath the Arctic Ocean hold vast amounts of methane. Just one part of the Arctic Ocean alone, the East Siberian Arctic Shelf (ESAS, rectangle on map below, from the methane page), holds up to 1700 Gt of methane. A sudden release of just 3% of this amount could add over 50 Gt of methane to the atmosphere, and experts consider such an amount to be ready for release at any time (see above image).



Total methane burden in the atmosphere now is 5 Gt. The 3 Gt that has been added since the 1750s accounts for almost half of the (net) total global warming caused by people. The amount of carbon stored in hydrates globally was in 1992 estimated to be 10,000 Gt (USGS), while a more recent estimate gives a figure of 63,400 Gt (Klauda & Sandler, 2005). The ESAS alone holds up to 1700 Gt of methane in the form of methane hydrates and free gas contained in sediments, of which 50 Gt is ready for abrupt release at any time.



Imagine what kind of devastation an extra 50 Gt of methane could cause. Imagine the warming that will take place if the methane in the atmosphere was suddenly multiplied by 11.

Whiteman et al. recently calculated that such an event would cause $60 trillion in damage. By comparison, the size of the world economy in 2012 was about $70 trillion.

Shallow waters in the Arctic Ocean
Shallow waters and little hydroxyl

The danger is particularly high in the shallow seas that are so prominent in the Arctic Ocean, as illustrated by the light blue areas on the image on the right, from an earlier post.

Much of the waters in the Arctic Ocean are less than 50 m deep. Being shallow makes waters prone to warm up quickly during summer temperature peaks, allowing heat to penetrate the seabed.

This can destabilize hydrates and methane rising through shallow waters will then also enter the atmosphere more quickly, as it rises abruptly and in plumes.

Elsewhere in the world, releases from hydrates underneath the seafloor will largely be oxidized by methanotroph bacteria in the water and where methane does enter the atmosphere, it will quickly be oxidized by hydroxyl. In shallow waters, however, methane released from the seabed will quickly pass through the water column.

Large abrupt releases will also quickly deplete the oxygen in the water, making it harder for bacteria to break down the methane.

Very little hydroxyl is present in the atmosphere over the poles, as illustrated by the image on the right, showing global hydroxyl levels, from an earlier post.

In case of a large abrupt methane release from the Arctic Ocean, the little hydroxyl that is present in the atmosphere over the Arctic will therefore be quickly depleted, and the methane will hang around for much longer locally than elsewhere on Earth.

Shallow waters make the Arctic Ocean more prone to methane releases, while low hydroxyl levels make that methane that enters the atmosphere in the Arctic will contribute significantly to local warming and threaten to trigger further methane releases.

High levels of insolation in summer in the Arctic

Furthermore, the amount of solar radiation received by the Arctic at the June Solstice is higher than anywhere else on Earth, as illustrated by the image below, showing insolation on the Northern Hemisphere by month and latitude, in Watt per square meter, from an earlier post.

Warm water enters Arctic Ocean from Atlantic and Pacific Oceans

What further makes the situation in the Arctic particularly dangerous is that waters are not merely warmed up from the top down by sunlight that is especially strong over the Arctic Ocean in summer on the Northern Hemisphere, but also by warm water that flows into the Arctic Ocean from rivers and by warm water that enters the Arctic Ocean through the Bering Strait and through the North Atlantic Ocean. The latter danger is illustrated by the image below, from an earlier post.


Feedbacks

Furthermore, there are feedbacks that can rapidly accelerate warming in the Arctic, such as albedo losses due to loss of sea ice and snow cover on land, and changes to the jet stream resulting in more extreme weather. These feedbacks, described in more details at this page, are depicted in the image below.


Methane


Above image shows that methane levels on December 3, 2015, were as high as 2445 parts per billion (ppb) at 469 millibars, which corresponds to an altitude of 19,810 feet or 6,041 m.

The solid magenta-colored areas (levels over 1950 ppb) that show up over a large part of the Arctic Ocean indicate very strong methane releases.

Note there are many grey areas on above image. These are areas where no measurements could be taken, which is likely due to the strength of winds, rain, clouds and the jet stream, as also illustrated by the more recent (December 5, 2015) images on the right.

The polar jet stream on the Northern Hemisphere shows great strength, with speeds as high as 243 mph or 391 km/h (over a location over japan marked by green circle) on December 5, 2015.

So, high methane levels may well have been present in these grey areas, but didn't show up due to the weather conditions of the moment.

Furthermore, the white geometric areas are due the way the satellite takes measurements, resulting in areas that are not covered.

Finally, it should be noted that much of the methane will have been broken down in the water, before entering the atmosphere, so what shows up in the atmosphere over the Arctic is only part of the total amount of methane that is released from the seafloor.

In conclusion, the high methane levels showing up over the Arctic indicate strong methane releases from the seafloor due to warm waters destabilizing sediments that contain huge amounts of methane in the form of free gas and hydrates.

Climate Plan

As global warming continues, the risk increases that greater ocean heat will reach the Arctic Ocean and will cause methane to be released in large quantities from the Arctic Ocean seafloor. The 2015 El Niño has shown that a huge amounts of ocean heat can accumulate at a depth greater than 100 m (328 ft). Conditions in the Arctic and feedbacks make that methane threatens to be released there abruptly and in large quantities as warming continues.

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



On November 24, 2015, equatorial waters at ≈100 m (328 ft) depth at 110-135°W were over 6°C (10.8°F) warmer than average...
Posted by Sam Carana on Friday, December 4, 2015