High Methane Readings continue over Depth of Arctic Ocean

The image below contains 12 frames, with methane readings recorded over 12 days in the first half of October 2013.

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As discussed in earlier posts at this blog, high methane readings have been recorded recently over the depth of Arctic Ocean. Above image shows that these high readings are continuing. The image below shows that at 469 mb, the altitude at which the highest reading was recorded on the afternoon of October 13, methane shows up very prominently over the Arctic Ocean.

The fact that little methane shows up elsewhere indicates that methane is present at high levels, at times over 2200 ppb, over the depth of the Arctic Ocean, and that these high levels result from methane that originates from hydrates under the seabed.

The image below, with methane readings over the past few days (from October 12 10:00 pm to October 14 11:23 pm), shows high levels of methane over the depth of the Arctic Ocean.

The image below shows methane readings at 586 mb, the altitude at which the highest methane reading was recorded on the afternoon of October 14 (a reading of 2248 ppb). Again, methane is present very prominently over the depth of the Arctic Ocean.

Post by Sam Carana.

 

Methane over deep waters of Arctic Ocean

The image below shows a lot of methane over deeper parts of oceans, in particular the Arctic Ocean.

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Let's zoom in and take a closer look at what's happening.

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As earlier discussed in the post Methane release caused by earthquakes, there has been a lot of seismic activity in the Aleutian Islands region all the way up into Alaska, including an earthquake with a magnitude of 7 on the Richter scale on August 30, 2013, and several more recent earthquakes with a higher magnitude than 6 on the Richter scale.

An earthquake with a magnitude of 4.6 on the Richter scale hit the Laptev Sea on September 28, 2013. Furthermore, there have been several earthquakes in Siberia, while an earthquake with a magnitude of 6.7 on the Richter scale recently hit the Sea of Okhotsk, which occurred at a depth of 359.3 miles (578.24 km). Earthquakes at such a depth can be felt at great distances from the epicenter and can destabilize methane hydrates.

The presence of methane over the deeper parts of the Arctic Ocean has been discussed in a number of post at this blog recently (see under related, below). It should serve as a warning to those who believed that all methane escaping from deep-sea hydrates would be oxidized in the water by microbes before entering the atmosphere.

The IPCC appears to still close its eyes for such scenarios. Look at this screenshot from IPCC AR5 WGI TS.3.7:

Low release this century? Well, the danger may seem low now in many places, but the situation is already very dangerous in the Arctic, where hydroxyl levels in the atmosphere are very low, where water temperatures can show huge anomalies and where seas can be very shallow and at times become super-saturated with methane, to the extent that oxygen depletion in the water prevents methane oxidation. In the case of large abrupt release, waters will soon become super-saturated with methane locally, especially in the shallow parts of the Arctic Ocean. Furthermore, low sea temperatures and the peculiarities of currents create conditions in the Arctic Ocean that are not beneficial to the kind of growth of microbes that would decompose methane in oceans elsewhere.

How much methane are we talking about? One look at the top image shows that there's a huge amount of methane over the Arctic Ocean. On October 3, 2013, a peak reading was recorded of 2283 ppb and that wasn't even the highest recent reading, as illustrated by the graph below.

Where were these large amounts of methane released? The animation below shows methane methane readings of over 1950 ppb on October 3, 2013, on the afternoon only and with readings at only four relatively low altitudes, with methane over the Arctic Ocean dominating the picture.

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As the animation further shows, methane seems to perforate ice that currently has the highest concentration levels. Or, the methane could have been bubbling up along the edges of the sea ice. Anyway, methane over deep waters is a worrying development, as it could indicate hydrate destabilization that could become worse.

Does the IPCC point out such dangers? In TS.4.5, the IPCC seems to reach the opposite conclusion, adding that it does so with high confidence:

This is not a trivial matter. A study by Gail Whiteman, Chris Hope and Peter Wadhams, recently published in Nature, concludes that a 50Gt methane release in the Arctic would cause $60 trillion in damages. By comparison, the size of the world economy in 2012 was about $70 trillion. The study adds that such a methane pulse will "bring forward 15–35 years the average date at which the global mean temperature rise exceeds 2°C above pre-industrial levels".

Given that warnings such as addressed by such studies have been sounded for years, one would have expected the IPCC to have taken a very close look at such scenarios. So, what made the IPCC so confident that such catastrophic developments will not eventuate this century? Was there robust evidence behind such a conclusion? Or did the IPCC simply overlook concerns about methane release from the Arctic Ocean seabed? More about that in the next post.

Related

- Methane hydrate myths
http://methane-hydrates.blogspot.com/p/myths.html

- Methane hydrates
http://methane-hydrates.blogspot.com/2013/04/methane-hydrates.html

- Vast costs of Arctic change, in Nature, vol 499, pp 401-403, July 25, 2013
by Gail Whiteman, Chris Hope and Peter Wadhams
http://www.nature.com/nature/journal/v499/n7459/full/499401a.html
http://www.nature.com/nature/journal/v499/n7459/pdf/499401a.pdf

- Methane release caused by earthquakes
http://arctic-news.blogspot.com/2013/09/methane-release-caused-by-earthquakes.html

- Earthquake hits Laptev Sea

http://arctic-news.blogspot.com/2013/09/earthquake-hits-laptev-sea.html

- North Hole
http://arctic-news.blogspot.com/2013/09/north-hole.html

- Sea of Okhotsk
Methane-hydrates.blogspot.com/2013/06/sea-of-okhotsk.html

- Seismic activity, by Malcolm Light and Sam Carana (2011)
Arctic-news.blogspot.com/p/seismic-activity.html

- Thermal expansion of the Earth's crust necessitates geoengineering (2011)
Arctic-news.blogspot.com/p/thermal-expansion.html

Post by Sam Carana.

Open Water In Areas Around North Pole

In some areas around the North Pole, thickness of the sea ice has declined to virtually zero, i.e. open water.

What could have caused this open water? Let's go through some of the background.

North Hemisphere snow cover has been low for some time. Snow cover in May 2013 was the lowest on record for Eurasia. There now is very little snow left, as shown on the image right, adapted from the National Ice Center.

Low snow cover is causing more sunlight to be absorbed, rather than reflected back into space. As can be expected, there now are high surface temperatures in many areas, as illustrated by the NOAA image below. Anomalies can be very high in specific cases. Zyryanka, Siberia, recently recorded a high of 37.4 C, against normal high temperatures of 20 C to 21 C for this time of year. Heat wave conditions were also recorded in Alaska recently (satellite image of Alaska below).

NASA image June 17, 2013, credit: NASA/Jeff Schmaltz, LANCE MODIS Rapid Response Team, NASA GSFC - from caption by Adam Voiland: "Talkeetna, a town about 100 miles north of Anchorage, saw temperatures reach 96°F (36°C) on June 17. Other towns in southern Alaska set all-time record highs, including Cordova, Valez, and Seward. The high temperatures also helped fuel wildfires and hastened the breakup of sea ice in the Chukchi Sea."

Accordingly, a large amount of relatively warm water from rivers has flowed into the Arctic Ocean, in addition to warm water from the Atlantic and Pacific Oceans.

Sea surface temperatures have been anomalously high in many places around the edges of the sea ice, as also shown on the NOAA image below.

Nonetheless, as the above images also make clear, sea surface temperatures closer to the North Pole have until now remained at or below zero degrees Celsius, with sea ice cover appearing to remain in place. The webcam below from the North Pole Environmental Observatory shows that there still is a lot of ice, at least in some parts around the North Pole.

Webcam #2 of the North Pole Environmental Observatory monitoring UPMC's Atmospheric Buoy, June 21, 2013

So, what could have caused the sea ice to experience such a dramatic thickness decline in some areas close to the North Pole?

Firstly, as discussed in earlier posts, there has been strong cyclonic activity over the Arctic Ocean (see also Arctic Sea Ice blog post). This has made the sea ice more prone and vulnerable to the rapid decline that is now taking place in many areas.

Furthermore, Arctic sea ice thickness is very low, as illustrated by the image below.

Arctic sea ice volume/extent ratio, adapted by Sam Carana from an image by Neven (click to enlarge)

Finally, there has been a lot of sunshine at the North Pole. At this time of year, insolation in the Arctic is at its highest. Solstice (June 20 or June 21, 2013, depending on time zone) is the day when the Arctic receives the most hours of sunlight, as Earth reaches its maximum axial tilt toward the sun of 23° 26'. In fact, insolation during the months June and July is higher in the Arctic than anywhere else on Earth, as shown on the image below.

Monthly insolation for selected latitudes -  adapted from Pidwirny, M. (2006), in "Earth-Sun Relationships and Insolation",  Fundamentals of Physical Geography, 2nd Edition. 

In conclusion, the current rapid sea ice thickness decline close to the North Pole is mostly due to a combination of earlier cyclonic activity and lots of sunlight, while the sea ice was already very thin to start with. The cyclone broke up the sea ice at the center of the Arctic Ocean, which is turn made it more prone to melting rapidly. The cyclone did more, though, as contributor to the Arctic-news blog Veli Albert Kallio explains:

"The ocean surface freezes if the temperature falls below -2.5C. The reason for the negative melting point is the presence of 4-5% of sea salt. Only in the polar regions does the sea surface cool sufficiently for sea ice to form during winters.

The sea ice cover is currently thinning near the North Pole between 80-90 degrees north. This part of the ocean is very deep. It receives heat of the Gulf Stream from the south: as the warm water vapourises, its salt content to water increases. This densifies the Gulf Stream which then falls onto the sea floor where it dissipates its heat to the overlying water column. The deep basin of the Arctic Ocean is now getting sufficiently warmed for the thin sea ice cover to thin on top of it. The transportation of heat to the icy surface is combined with the winds that push cold surface water down while rising heat to surface."

Indeed, vertical mixing of the water column was enhanced due to cyclonic activity, and this occurred especially in the parts of the Arctic Ocean that also are the deepest, as illustrated by the animation below.

Legend right: Ice thickness in m from Naval Research Laboratory
Legend bottom: Sea depth (blue) and land height (brown/green)
in m from NIBCAO Arctic map at NOAA

The compilation of images below shows how the decline of sea ice has taken place in a matter of weeks.

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This spells bad news for the future. It confirms earlier analyses (see links below) that the sea ice will disappear altogether within years. It shows that the sea ice is capable of breaking up abruptly, not only at the outer edges, but also at the center of the Arctic Ocean. As the Arctic sea ice keeps declining in thickness, it does indeed look set to break up and disappear abruptly across most of the Arctic Ocean within a few years. Models that are based on sea ice merely shrinking slowly from the outer edges inward should reconsider their projections accordingly.

Related

- Getting the Picture
http://arctic-news.blogspot.com/2012/08/getting-the-picture.html

- Supplementary evidence by Prof. Peter Wadhams
http://arctic-news.blogspot.com/2012/04/supplementary-evidence-by-prof-peter.html