Arctic Ocean invaded by hot, salty water

Sea surface temperatures on the Northern Hemisphere have been rising dramatically over the years, as illustrated by above image, indicating that the latent heat tipping point is getting crossed, while the methane hydrates tipping point could get crossed soon, depending on developments.

At the moment, the surface temperature of most of the Arctic ocean's is still below 0°C.

Heat is entering the Arctic Ocean from the south, as illustrated by the image on the right. Hot, salty water is entering the Arctic Ocean from the Atlantic Ocean as currents dive underneath the ice, causing the ice to melt from below. 

[ click on images to enlarge ]

The image on the right, from the NSIDC article A step in our Spring, compares sea ice age between March 12 to 18 for the years 1985 (a) and 2021 (b).

The bottom graph (c) shows a time series from 1985 to 2021 of percent ice coverage of the Arctic Ocean domain. The Arctic Ocean domain is depicted in the inset map with purple shading.

At the end of the ice growth season in mid-March, 73.3% of the Arctic Ocean domain was covered by first-year ice, while 3.5% was covered by ice 4+ years old. 

This compares to 70.6% and 4.4% respectively in March 2020.

In March 1985, near the beginning of the ice age record, the Arctic Ocean region was comprised of nearly equal amounts of first-year ice (39.3%) and 4+ year-old ice (30.6%).

Sea ice that hasn't yet survived a summer melt season is referred to as first-year ice. This thin, new ice is vulnerable to melt and disintegration in stormy conditions. Ice that survives a summer melt season can grow thicker and less salty, since snow that thickens the ice contains little salt. Thickness and salt content determine the resistance of the ice to melt. Multiyear ice is more likely to survive temperatures that would melt first-year ice, and to survive waves and winds that would break up first-year ice.

The image on the right shows a forecast of the thickness of the sea ice, run on May 20, 2021 and valid for May 21, 2021. 

An area is visible north of Severnaya Zemlya toward the North Pole where thickness is getting very thin, while there is one spot where the ice has virtually disappeared. 

The spot is likely a melting iceberg, the animation on the right shows that the spot has been there for quite a few days, while the freshwater in this spot appears to result from melting amid salty water. 

Overall, sea ice is getting very thin, indicating that the buffer constituted by the sea ice underneath the surface is almost gone, meaning that further heat entering the Arctic Ocean will strongly heat up the water. 

As the animation underneath on the right shows, freshwater is entering the Arctic Ocean due to runoff from land, i.e. rainwater from rivers, meltwater from glaciers and groundwater runoff from thawing permafrost. 

At the same time, very salty water is entering the Arctic Ocean from the Atlantic Ocean. 

The map below shows how salty and hot water from the Atlantic Ocean enters the Arctic Ocean along two currents, flowing on each side of Svalbard, and meeting at this area north of Severnaya Zemlya where thickness is getting very low. 

The blue color on the map indicates depth (see scale underneath). 

The image below, by Malcolm Light and based on Max & Lowrie (1993), from a recent post, shows vulnerable Arctic Ocean slope and deep water methane hydrates zones below 300 m depth. 

Malcolm Light indicates three areas: 

Area 1. Methane hydrates on the slope;

Area 2. Methane hydrates on the abyssal plane; 

Area 3. Methane hydrates associated with the spreading Gakkel Ridge hydro-thermal activity (the Gakkel Riidge runs in between the northern tip of Greenland and the Laptev Sea). 

The freezing point of freshwater is 0°C or 32°F. For salty water, the freezing point is -2°C or 28.4°F.

During April 2021, sea ice was about 160 cm thick.

In June and July 2021, thickness will fall rapidly, as illustrated by the image on the right by Nico Sun. 

Sea ice acts as a buffer, by consuming energy in the process of melting, thus avoiding that this energy causes a temperature rise of the water. 

As long as there is sea ice in the water, this sea ice will keep absorbing heat as it melts, so the temperature will not rise at the sea surface and remain at zero°C. The amount of energy that is consumed in the process of melting the ice is as much as it takes to heat an equivalent mass of water from zero°C to 80°C.

The accumulated ice melt energy until now is the highest on record, as illustrated by the image on the right, by Nico Sun.

The image below further illustrate the danger. As the temperature of the water keeps rising, more heat will reach sediments at the seafloor of the Arctic Ocean that contain vast amounts of methane, as discussed at this page and in this post.

Ominously, methane levels reached a peak of 2901 ppb at 469 mb on May 13, 2021. 

Research

In the extract of a 2008 paper, Natalia Shakhova et al. conclude: ". . we consider release of up to 50 Gt of predicted amount of hydrate storage as highly possible for abrupt release at any time."

The video below contains excerpts from Nick Breeze's interview with Natalia Shakhova at the European Geophysical Union in Vienna, 2012, on the likelihood and timeframe of a large methane release from the seafloor of the Arctic Ocean. 

Natalia Shakhova: "The total amount of methane in the atmosphere is about 5Gt. The amount of carbon in the form of methane in this Arctic shelf is - approximately - from hundreds to thousands Gt and, of course, only 1% of [such an] amount is required to double the atmospheric burden of methane."

"But to destabilize 1% of this carbon pool, I think, not much effort is needed, considering the state of the permafrost and the amount of methane involved, because what divides the methane from the atmosphere is a very shallow water column and the weakening permafrost, which is losing its ability to seal, to serve as a seal, and this is, I think, not a matter of thousands of years, it's a matter of decades, at most hundred years." 

(Natalia talks with Igor Semiletov)
Natalia Shakhova: "Just because this area is seismically and tectonically active, and there was some investigation that the tectonic activity was increasing, and the seismic activity, the destabiliation of the ground, just mechanical forcing destabiliation [may suffice to act as] additional pathway for this methane to escape. There are many factors that are very convincing for us [to conclude] that it might happen."

Elaborating on the timeframe.
Natalia Shakhova: "Not any time, any time sounds like it might happen today, it might happen tomorrow, the day after tomorrow . . " 
Igor Simelitov: "It might!"

The image below was created with content from a 2019 paper by Natalia Shakhova et al. It concludes that methane releases could potentially increase by 3-5 orders of magnitude, considering the sheer amount of methane preserved within the shallow East Siberian Arctic Shelf seabed deposits and the documented thawing rates of subsea permafrost reported recently.

In a 2021 paper by researchers from Europe, Russia and the U.S., results from field research are published showing that methane is getting released from locations deep below the submarine permafrost. Lead author, Julia Steinbach, from Stockholm University, says: “The permafrost is a closed lid over the seafloor that’s keeping everything in place. And now we have holes in this lid.” 

In the video below, Nick Breeze interviews Igor Semiletov on methane plumes detected during this 2020 field research over the East Siberian Arctic Shelf (ESAS).

In the video below, Nick Breeze interviews Örjan Gustafsson on field research on methane in the East Siberian Arctic Shelf (ESAS)

In the video below, Peter Wadhams analyses the threat of Arctic methane releases.

In the video below, Guy McPherson discusses the situation.

In conclusion, temperatures could rise dramatically soon. A 3°C will likely suffice for humans to go extinct, making it in many respects rather futile to speculate about what will happen in the longer term. On the other hand, the right thing to do is to help avoid the worst things from happening, through comprehensive and effective action as described in the Climate Plan.

Links

• NOAA Climate at a Glance

https://www.ncdc.noaa.gov/cag/global/time-series/nhem/ocean/ann/4/1997-2020

• Danish Meteorological Institute - Arctic temperature
http://ocean.dmi.dk/arctic/meant80n.uk.php

• Freezing point of water - Climate Change: Arctic sea ice

https://www.climate.gov/news-features/understanding-climate/climate-change-minimum-arctic-sea-ice-extent

• Arctic surface temperature

http://ocean.dmi.dk/anim/index.uk.php

• NSIDC: A step in our Spring, image credit: T. Tschudi, University of Colorado, and W. Meier and J.S. Stewart, National Snow and Ice Data Center/Image by W. Meier

https://nsidc.org/arcticseaicenews/2021/05/a-step-in-our-spring

• Arctic sea ice - thickness and salinity - navy.mil
https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/arctic.html

• CryosphereComputing - by Nico Sun
https://cryospherecomputing.tk

• A 4.5 km resolution Arctic Ocean simulation with the global multi-resolution model FESOM 1.4 - by Qiang Wang et al. 

https://gmd.copernicus.org/articles/11/1229/2018/

• Max, M.D. & Lowrie, A. 1993. Natural gas hydrates: Arctic and Nordic Sea potential. In: Vorren, T.O., Bergsager, E., Dahl-Stamnes, A., Holter, E., Johansen, B., Lie, E. & Lund, T.B. Arctic Geology and Petroleum Potential, Proceedings of the Norwegian Petroleum Society Conference, 15-17 August 1990, Tromso, Norway. Norwegian Petroleum Society (NPF), Special Publication 2 Elsevier, Amsterdam, 27-53.

https://www.elsevier.com/books/arctic-geology-and-petroleum-potential/vorren/978-0-444-88943-0

• Extinction by 2027- by Malcolm Light

https://arctic-news.blogspot.com/2021/05/extinction-by-2027.html

• MetOp satellite - methane
https://www.ospo.noaa.gov/Products/atmosphere/soundings/iasi

• Anomalies of methane in the atmosphere over the East Siberian shelf: Is there any sign of methane leakage from shallow shelf hydrates? - by Shakhova, Semiletov, Salyuk and Kosmach (2008)
https://www.cosis.net/abstracts/EGU2008/01526/EGU2008-A-01526.pdf

• Understanding the Permafrost–Hydrate System and Associated Methane Releases in the East Siberian Arctic Shelf - by Natalia Shakhova, Igor Semiletov and Evgeny Chuvilin 
https://www.mdpi.com/2076-3263/9/6/251

• A Massive Methane Reservoir Is Lurking Beneath the Sea 

https://eos.org/articles/a-massive-methane-reservoir-is-lurking-beneath-the-sea

• Source apportionment of methane escaping the subsea permafrost system in the outer Eurasian Arctic Shelf - by Julia Steinbach et al. 
https://www.pnas.org/content/118/10/e2019672118

• The Threat
https://arctic-news.blogspot.com/p/threat.html

• When will we die?
https://arctic-news.blogspot.com/2019/06/when-will-we-die.html

• A rise of 18°C or 32.4°F by 2026?
https://arctic-news.blogspot.com/2019/02/a-rise-of-18c-or-324f-by-2026.html

• Most Important Message Ever
https://arctic-news.blogspot.com/2019/07/most-important-message-ever.html

• Climate Plan
https://arctic-news.blogspot.com/p/climateplan.html

Horrific Methane Eruptions in East Siberian Sea

A catastrophe of unimaginable propertions is unfolding in the Arctic Ocean. Huge quantities of methane are erupting from the seafloor of the East Siberian Sea and entering the atmosphere over the Arctic Ocean.

As the top image above shows, peak levels as high as 2363 ppb were recorded at an altitude of 19,820 ft (6041 m) on the morning of August 12, 2014. The middle image shows that huge quantities of methane continued to be present over the East Siberian Sea that afternoon, while the bottom image shows that methane levels as high as 2441 ppb were recorded a few days earlier, further indicating that the methane did indeed originate from the seafloor of the East Siberian Sea.

On August 12, 2014, peak methane levels at higher altitudes were even higher than the readings mentioned on above image. Levels as high as 2367 ppb were reached at an altitude of 36,850 ft (11,232 m). Such high levels have become possible as the huge quantities of methane that were released from the seafloor of the Arctic Ocean over the period from October 2013 to March 2014, have meanwhile descended to lower latitudes where they show up at higher altitudes.

Methane eruptions from the Arctic Ocean's seafloor helped push up mean global methane levels to readings as high as 1832 ppb on August 12, 2014.

Ironically, the methane started to erupt just as an international team of scientists from Sweden, Russia and the U.S. (SWERUS-C3), visiting the Arctic Ocean to measure methane, had ended their research.

Örjan Gustafsson describes part of their work: “Using the mid-water sonar, we mapped out an area of several kilometers where bubbles were filling the water column from depths of 200 to 500 m. During the preceding 48 h we have performed station work in two areas on the shallow shelf with depths of 60-70m where we discovered over 100 new methane seep sites.”

Örjan Gustafsson adds that “a tongue of relatively warm Atlantic water, with a core at depths of 200–600 m may have warmed up some in recent years. As this Atlantic water, the last remnants of the Gulf Stream, propagates eastward along the upper slope of the East Siberian margin, our SWERUS-C3 program is hypothesizing that this heating may lead to destabilization of upper portion of the slope methane hydrates.”

Schematics of key components of the Arctic climate-cryosphere-carbon system that are addressed by the SWE-C3 Program. a,b) Sonar images of gas plumes in the water column caused by sea floor venting of methane (a: slope west of Svalbard, Westbrook et al., 2009; b: ESAO, Shakhova et al., 2010, Science). c) Coastal erosion of organic-rich Yedoma permafrost, Muostoh Island, SE Laptev Sea. d) multibeam image showing pockmarks from gas venting off the East Siberian shelf. e) distribution of Yedoma permafrost in NE Siberia. f) Atmospheric venting of CH₄, CO₂. (SWERUS-C3)

Örjan Gustafsson further adds that SWERUS-C3 researchers have on earlier expeditions documented extensive venting of methane from the subsea system to the atmosphere over the East Siberian Arctic Shelf.

In 2010, team members Natalia Shakhova and Igor Semiletov estimated the accumulated methane potential for the Eastern Siberian Arctic Shelf alone to be as follows:
- organic carbon in permafrost of about 500 Gt;
- about 1000 Gt in hydrate deposits; and
- about 700 Gt in free gas beneath the gas hydrate stability zone.

Back in 2008, Shakhova et al. wrote a paper warning that “we consider release of up to 50 Gt of predicted amount of hydrate storage as highly possible for abrupt release at any time.”

Last year, a team of researchers including Professor Peter Wadhams calculated that such a 50 Gt release would cause global damage with a price-tag of $60 trillion.

As Prof Wadhams explains in the video below: “We really have no choice except to seriously consider the use of geoengineering.”

Sea surface temperatures as high as 18.8°C are now recorded at locations where warm water from the Pacific Ocean is threatening to invade the Arctic Ocean.

At the same time, huge amounts of very warm water are carried into the Arctic Ocean by the Gulf Stream through the North Atlantic. The image below illustrates how the Gulf Stream brings very warm water to the edge of the sea ice.

Waters close to Svalbard reached temperatures as high as 62°F (16.4°C) on July 29, 2014 (green circle). Note that the image below shows sea surface temperatures only. At greater depths (say about 300 m), the Gulf Stream is pushing even warmer water through the Greenland Sea than temperatures at the sea surface.

Since the passage west of Svalbard is rather shallow, a lot of this very warm water comes to the surface at that spot, resulting in an anomaly of 11.1°C. The high sea surface temperatures west of Svalbard thus show that the Gulf Stream can carry very warm water (warmer than 16°C) at greater depths and is pushing this underneath the sea ice north of Svalbard. Similarly, warm water from greater depth comes to the surface where the Gulf Stream pushes it against the west coast of Novaya Zemlya.

[ click on image to enlarge ]

As Malcolm Light writes in an earlier post: The West Spitzbergen Current dives under the Arctic ice pack west of Svalbard, continuing as the Yermak Branch (YB on map) into the Nansen Basin, while the Norwegian Current runs along the southern continental shelf of the Arctic Ocean, its hottest core zone at 300 metres depth destabilizing the methane hydrates en route to where the Eurasian Basin meets the Laptev Sea, a region of extreme methane hydrate destabilization and methane emissions.

The images below give an impression of the amount of heat transported into the Arctic Ocean.

The image below gives an idea how methane eruptions from the seafloor of the Arctic Ocean could unfold over the coming decades. For more on this image, see this post and this page.

As said, the situation is dire and calls for comprehensive and effective action, as discussed at the Climate Plan blog at climateplan.blogspot.com and as illustrated by the image below.