Showing posts with label Arctic. Show all posts
Showing posts with label Arctic. Show all posts

Friday, September 15, 2023

Seafloor methane tipping point reached

The bold black line at the top of the image below, adapted from Climate Reanalyzer, shows extremely high sea surface temperatures up to September 13, 2023, much higher than in any previous year on record.

The image below, created with NASA data, shows why these extremely high sea surface temperatures are so worrying. The image shows monthly mean global surface temperature anomalies (open ocean) vs 1901-1930. The ochre trend, based on January 1900-August 2023 data, indicates the latent heat tipping point was crossed in 2021 and the seafloor methane tipping point could be crossed in 2033. The red trend, based on August 2008-August 2023 data and better reflecting variables such as El Niño, indicates that the seafloor methane tipping point could be crossed late 2023. Data show the seafloor methane tipping point was reached in August 2023.

The latent heat tipping point is estimated to correspond with a sea surface temperature anomaly of 1°C above the long term average, 1901-1930 on the above image, as discussed in earlier posts such as this one.

Sea ice constitutes a latent heat buffer, consuming incoming heat as it melts. While the ice is melting, all energy (at 334 J/g) goes into changing ice into water and the temperature remains at 0°C (273.15K or 32 °F). Once all ice has turned into water, all subsequent energy goes into heating up the water, and will do so at 4.18 J/g for every 1°C the temperature of the water rises. 

[ The Latent Heat Buffer ]
Once Arctic sea ice has become very thin, ocean heat that was previously consumed by melting the sea ice, no longer gets consumed by melting of the sea ice, and further incoming heat instead gets absorbed by the Arctic Ocean, rapidly pushing up the temperature of the water of the Arctic Ocean. 

The latent heat tipping point has meanwhile been crossed. Loss of this buffer is linked to the seafloor methane tipping point, i.e. the point where additional heat reaches the seafloor and destabilizes hydrates contained in sediments at the seafloor. This tipping point comes with multiple self-reinforcing feedback loops, such as explosive growth in methane volume setting off further destabilization, rapid rise of Arctic temperatures, loss of permafrost and loss of albedo, and release of further greenhouse gases.

Crossing of the seafloor methane tipping point will occur later than crossing of the latent heat tipping point, i.e. the seafloor methane tipping point corresponds with a higher ocean temperature anomaly, estimated to correspond with a sea surface temperature anomaly of 1.35°C above the long term average.

The current situation is particularly precarious in the Arctic, as the North Atlantic Ocean is very hot and the Gulf Stream keeps pushing hot water toward the Arctic Ocean, while Arctic sea ice has become very thin and the latent heat tipping point has been crossed.

As the temperature of the Arctic Ocean keeps rising, more heat can reach sediments located at the seafloor, since much of the Arctic Ocean is very shallow and sediments at the seafloor of the Arctic Ocean can contain vast amounts of methane.

The danger is that additional heat will destabilize hydrates in these sediments, leading to explosive eruptions of methane, as its volume increases 160 to 180-fold when leaving the hydrates, and resulting in huge eruptions of methane both from the destabilizing hydrates and from methane that is present in the form of free gas underneath the hydrates.

[ from earlier post, click on images to enlarge ]

The above image, from an earlier post, illustrates that warnings have been given before about the danger of these two tipping points getting crossed in the Arctic. In the above image, the trends are based on annual sea surface temperature data for the Northern Hemisphere. The seafloor methane tipping point is estimated to correspond with ocean temperature anomalies reaching 1.35°C above the long term average.

The image below further illustrates the high sea surface temperatures in and around the Arctic Ocean, with the red to yellow colors indicating temperature anomalies above the 1981-2011 average, and the green circle marking a sea surface temperature anomaly near the North Pole of 0.4°C on September 13, 2023.  


The image below illustrates how incoming ocean heat that previously was consumed in the process of melting of the sea ice, is now causing the water of the Arctic Ocean to heat up, with more heat reaching the seafloor of the Arctic Ocean, which has seas that in many places are very shallow.

[ Latent heat loss, feedback #14 on the Feedbacks page ]
Further adding to the danger is that destabilization of methane hydrates can cause huge amounts of methane to erupt with great force from the seafloor in the form of plumes. Consequently, little of the methane can be broken down in the water by microbes, while there is very little hydroxyl in the atmosphere over the Arctic Ocean to break down the methane that enters the atmosphere.


[ click on images to enlarge ]
Ominously, very high methane levels continue to be recorded at Barrow, Alaska, as illustrated by the above NOAA image.

The MetOp satellite image on the right shows methane levels, with the magenta color indicating the highest methane levels recorded at surface level (1000 mb), on September 15, 2023 am.

The N20 satellite image underneath shows methane levels at an altitude corresponding with 487 mb on September 10, 2023 am. The magenta color again indicates the highest methane levels recorded at the time.

Note the high levels over the Beaufort Sea and elsewhere over the Arctic Ocean, as well as high levels recorded over oceans in the Southern Hemisphere.

Climate Emergency Declaration

A catastrophe of unimaginable proportions is unfolding. Life is disappearing from Earth and runaway heating could destroy all life on Earth. At 5°C heating, most life on Earth will have disappeared. When looking only at near-term human extinction, 3°C will likely suffice.

The situation is dire and is getting more dire every day, which calls for a Climate Emergency Declaration and implementation of comprehensive and effective action, as described in the Climate Plan with an update at Transforming Society.


Links

• Climate Reanalyzer - daily sea surface temperature
https://climatereanalyzer.org/clim/sst_daily

• NASA - GISS Surface Temperature Analysis

• Record high North Atlantic sea surface temperature




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Sunday, September 10, 2023

Methane eruptions threaten


The above image, adapted from Climate Reanalyzer, shows that on September 8, 2023, the North Atlantic sea surface reached a new record high temperature, of 25.4°C, even higher than the record reached the day before.

The situation is critical! More heat entering the Arctic Ocean threatens to destabilize hydrates and cause huge amounts of methane to erupt and enter the atmosphere.

The image on the right, adapted from NASA Worldview, shows the poor state of the sea ice.

On September 8, 2023, the Polarstern reached the North Pole. The image below shows the research vessel and the sea ice at the North Pole.
 

The image on the right, adapted from University of Bremen, shows Arctic sea ice concentration and the route followed by the Polarstern. 

The threat is that, as the water of the Arctic Ocean keeps heating up, heat will reach the seafloor and destabilize methane hydrates contained in sediments at the seafloor, resulting in eruptions of huge amounts of methane. 

Erupting from the hydrates occurs at great force, since the methane expands 160 when decompressed, resulting in the methane rapidly rising in the form of plumes, leaving little or no opportunity for microbes to decompose the methane in the water column. Furthermore, the atmosphere over the Arctic contains very little hydroxyl, resulting in methane persisting in the air over the Arctic much longer than elsewhere. 

After months of very high temperatures, the Arctic reached a new record high temperature for the time of year, i.e. 1.52°C on September 10, 2023, an anomaly of 2.25°C.


Meanwhile, global sea ice extent is much lower than in any other year on record for this time of year.


Ominously, very high methane levels continue to be recorded at Barrow, Alaska, U.S. 

Conclusion

The situation is dire and is getting more dire every day, which calls for a Climate Emergency Declaration and implementation of comprehensive and effective action, as described in the Climate Plan with an update at Transforming Society.



Links

• Climate Reanalyzer - North Atlantic sea surface temperature

• NASA Worldview

• Polarstern reaches North Pole - Research icebreaker at the northernmost point of the earth for the seventh time

• University of Bremen - Arctic sea ice concentration

• Arctic Data archive System

• NOAA - Barrow Atmospheric Baseline Observatory, United States

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

• Transforming Society
https://arctic-news.blogspot.com/2022/10/transforming-society.html

• Climate Emergency Declaration
https://arctic-news.blogspot.com/p/climate-emergency-declaration.html


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Saturday, August 12, 2023

Return of the Blob?


The Blob is a large mass of water with relatively high heat content, floating at the surface and underneath the surface of the North Pacific Ocean. The Blob did appear several times before, including in 2016, which was a strong El Niño year. The above image shows high sea surface temperature anomalies in the North Pacific on August 10, 2023, raising the question of whether this constitutes a return of the Blob.

As temperatures rise, the Arctic is heating more rapidly than the rest of the world. The narrowing temperature difference between the Arctic and the Tropics is weakening the speed at which the jet stream circumnavigates Earth and this is making the jet stream more wavy.

In a 2012 study, Jennifer Francis et al. warned that this makes atmospheric blocking events in the Northern Hemisphere more likely, aggravating extreme weather events related to stagnant weather conditions, such as droughts, flooding and heatwaves. The Blob appears to be the marine version of a heatwave on land.

The image below shows that, on August 12, 2023, sea surface temperatures were as much as 7°C or 12.6°F higher than 1981-2011 in the Pacific Ocean (at the green circle, follow the arrow). A strongly deformed Jet Stream shows many circular wind patterns, prolonging, intensifying and increasing the occurrence of extreme weather events such as accumulation of heat during heatwaves. 


Is the Kuroshio Current slowing down?

The Kuroshio Current is an ocean current that carries heat along its path in the North Pacific, similar to the Gulf Stream in the North Atlantic Ocean. Is the Kuroshio Current slowing down as temperatures rise and is such slowing down causing hot water to accumulate in the western part of the North Pacific, leading to a return of a new Blob moving across the North Pacific toward the coast of North America?

The North Atlantic has been experiencing record high sea surface temperatures recently. A return of the Blob increases the danger of more heat reaching sediments at the seafloor of the Arctic Ocean.

[ 2022 animation ]
The animation on the right shows how remnants of Typhoon Merbok were forecast to enter the Arctic Ocean through the Bering Strait from September 17 to 19, 2022.

Studies, some of them dating back more than two decades, show that over the shallow East Siberian Arctic Shelf (ESAS) winds at times can mix the water column from the top to the bottom. A 2005 study of the ESAS led by Igor Semiletov recorded water temperatures at the seafloor, in September 2000, of 4.7°C at 20m depth at one location and 2.11°C at 41m depth at another location, with salinity levels of 29.7‰ and of 31.7‰, respectively.

A deformed Jet Stream, in combination with a cyclone, could result in strong winds abruptly pushing a huge amount of heat through the Bering Strait into the Arctic Ocean. This could cause methane hydrates to destabilize and huge amounts of methane to erupt from the seafloor and enter the atmosphere.

Conclusion

The situation is dire and is getting more dire every day, which calls for a Climate Emergency Declaration and implementation of comprehensive and effective action, as described in the Climate Plan with an update at Transforming Society.


Links

• The Blob

• Evidence Linking Arctic Amplification to Extreme Weather in Mid-Latitudes, by Jennifer Francis et al. (2012)
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2012GL051000 

• The Kuroshio current
https://en.wikipedia.org/wiki/Kuroshio_Current

• Record high North Atlantic sea surface temperature

• Remnants of Typhoon Merbok forecast to enter the Arctic Ocean through the Bering Strait from September 17 to 19, 2022.

• The East Siberian Sea as a transition zone between Pacific-derived waters and Arctic shelf waters - by Igor Semiletov et al. (2005)
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2005GL022490

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

• Transforming Society
https://arctic-news.blogspot.com/2022/10/transforming-society.html

• Climate Emergency Declaration
https://arctic-news.blogspot.com/p/climate-emergency-declaration.html



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Wednesday, August 9, 2023

Arctic sea ice August 2023

Arctic Ocean heating up

There are at least five mechanisms that cause the water of the Arctic Ocean to heat up, as described below. 

1. Direct Heat. Heat from sunlight directly reaches the surface, i.e. the sea ice or the water of the Arctic Ocean.

The August 8, 2023, image on the right, from Climate Reanalyzer, shows a 1-3 days forecast of maximum surface temperatures (2m). Heatwaves over land can extend over the Arctic Ocean. 

High levels of emissions and greenhouse gases over the Arctic increase the amount of heat that is reaching the water of the Arctic Ocean and the sea ice. 

The NASA satellite image below shows smoke from forest fires in Canada moving over the Beaufort Sea and over the sea ice on August 6, 2023. 
[ click on images to enlarge ]

A recent study highlights that forest fires can strongly contribute to the temperature rise. Smoke, soot and further aerosols settling on the sea ice also darken the surface, resulting in more sunlight getting absorbed (feedback #9 on the feedbacks page). 

The image on the right, from a Copernicus news release dated August 3, 2023, shows the dramatic growth in emissions from fires in Canada up to end July 2023. 

The news release quotes Copernicus Atmosphere Monitoring Service senior scientist, Mark Parrington, who comments: "As fire emissions from boreal regions typically peak at the end of July and early August, the total is still likely to continue rising for some more weeks."

The Climate Reanalyzer image below shows that the temperature in the Arctic was at a record high for the time of year of 5.64°C or 42.15°F on August 9, 2023. Earlier, a record temperature of 5.81°C or 42.46°F was reached (on July 27, 2023).

Arctic sea ice typically reaches its minimum extent half September, when temperatures in the Arctic fall below 0°C and water at the surface of the Arctic Ocean starts refreezing.


2. Heat from Rivers. Hot water from rivers ending in the Arctic Ocean is another way the water is heating up and this is melting the sea ice from the side.

The August 10, 2023, image below, from nullschool.net, illustrates the added impact of heat that is carried by rivers into the Arctic Ocean, with sea surface temperatures as high as 20.4°C or 68.7°F recorded at a location where the Mackenzie River flows into the Arctic Ocean (at the green circle, where the green arrow is pointing at).


On August 6, 2023, the sea surface was 14.5°C or 26.2°F hotter than in 1981-2011, at a nearby location where the Mackenzie River is flowing into the Arctic Ocean, as illustrated by the image below.


The image on the right shows that on August 10, 2023, the sea surface temperature was 17.6°C or 63.7°F at a location where the Lena River in Siberia enters the Arctic Ocean, i.e. 14.2°C or 25.5°F hotter than it was in 1981-2011 (at green circle).

The Lena River flows into the Laptev Sea which is mostly less than 50 meters deep, making it relatively easy for surface heat to reach the seafloor. 

The NOAA image underneath on the right shows sea surface temperatures in the Bering Strait as high as 19.2°C or 66.56°F on August 8, 2023.

The image illustrates that the water can heat up strongly where hot water from rivers and run-off from rainwater enters the Bering Strait.

3. Ocean Heat. Yet another mechanism is heat that is entering the Arctic Ocean from other oceans, i.e. from the North Atlantic Ocean and the Pacific Ocean. Sea ice underneath the sea surface is melting from below due to ocean heat. 

An earlier post discusses why we are currently facing record high sea surface temperatures in the North Atlantic.

The image below shows how the Gulf Stream is pushing ocean heat toward the Arctic Ocean, while sea surface temperatures show up as high as 33.1°C or 91.58°F on August 9, 2023. 


The Gulf Stream is an ocean current that extends into the Arctic Ocean, as pictured below and discussed at this page. This ocean current is driven by the Coriolis force and by prevailing wind patterns.

[ from earlier post ]

This ocean current contributes to the stronger and accelerating rise in temperature in the Arctic (compared to the rest of the world), which in turn causes deformation of the Jet Stream that can at times cause strong winds that speed up this ocean current, as discussed in earlier post such as this 2017 one. 

[ from earlier post ]

4. Sea ice moving out. The Arctic Ocean is also heating up as sea ice is getting pushed into the Atlantic Ocean. Even the thickest sea ice can break up into pieces and move along with the flow of meltwater from glaciers, ocean currents and/or strong wind.

[ Click on images to enlarge ]
The animation below, created with NASA Worldview satellite images, shows the northern tip of Greenland at the top left of each frame. The green square on the image on the right indicates the area of the animation. It's around Prinsesse Thyra Island in Northeast Greenland National Park. 

This is where typically the thickest sea ice is located. The animation shows the sea ice breaking up and moving out of the Arctic Ocean. What is left of the pieces will eventually melt in the Atlantic Ocean. Pieces of sea ice that are pushed out of the Arctic Ocean reduce the latent heat buffer, as they can no longer consume heat in the Arctic Ocean through melting.  


5. Sea ice sealing off the Arctic Ocean from the atmosphere

The sea ice used to reach its lowest extent approximately half September. With the change in seasons, air temperatures decrease and sea ice starts increasing in extent at the sea surface. The image below illustrates how, as the Arctic Ocean starts freezing over, less heat will from then on be able to escape to the atmosphere. Sealed off from the atmosphere by sea ice, greater mixing of heat in the water will occur down to the seafloor of the Arctic Ocean, as discussed in FAQ#21.

[ From the post September 2015 Sea Surface Warmest On Record ]

In October, sea ice has stopped melting and is increasing in extent at the surface of the Arctic Ocean. Also, as land around the Arctic Ocean freezes over, less fresh water will flow from rivers into the Arctic Ocean, while hot, salty water will continue to flow into the Arctic Ocean. As a result, the salt content of the Arctic Ocean increases, all the way down to the seafloor of the Arctic Ocean, increasing the danger that ice in cracks and passages in sediments at the seafloor will melt, allowing methane contained in the sediment to escape and enter the atmosphere.

[ Pingos and conduits. Hovland et al. (2006) ]
Warmer water reaching these sediments can penetrate them by traveling down cracks and fractures in the sediments, and reach the hydrates. The image on the right, from a study by Hovland et al., shows that hydrates can exist at the end of conduits in the sediment. Such conduits were formed when some of the methane did escape from such hydrates in the past. Heat can travel down such conduits relatively fast and reach methane hydrates that keep methane in cages of ice. As heat reaches the ice cages, a temperature rise less than 1°C can suffice to destabilize such cages, resulting in a huge abrupt eruption, as the methane expands more than 160 times in volume.

[ The Buffer has gone, feedback #14 on the Feedbacks page ]
Further increasing the danger, this return of the sea ice results in less moisture evaporationg from the water, which together with the change of seasons results in lower hydroxyl levels at the higher latitudes of the Northern Hemisphere, in turn resulting in less methane getting broken down in the atmosphere over the Arctic.

Feedbacks and further developments

More generally, the rapid temperature rise threatens to cause numerous feedbacks to accelerate and further developments to occur such as crossing of tipping points, with the danger that the temperature will keep rising.

In the video below, Peter Carter, Paul Beckwith and Dale Walkonen discuss the situation.


One such feedbacks is the formation and growth of a cold freshwater lid at the surface of the North Atlantic that enables large amounts of salty and relatively hot water to flow underneath this lid and underneath the remaining sea ice, to enter the Arctic Ocean, as discussed earlier here, as well as here and at the feedbacks page.


This further increases the danger of destabilization of methane hydrates contained in sediments at the seafloor of the Arctic Ocean. 

Ominously, some very high methane levels were recorded recently at Barrow, Alaska, as illustrated by the NOAA image below.
Conclusion

The situation is dire and the outlook is getting more grim every day, calling for a Climate Emergency Declaration and implementation of comprehensive and effective action, as described in the Climate Plan and as most recently discussed at Transforming Society.


Links

• Climate Reanalyzer - Outlook Forecast Maps

• NASA - Worldview
https://worldview.earthdata.nasa.gov

• Shortwave absorption by wildfire smoke dominated by dark brown carbon - by Rajan Chakrabarty et al.
https://www.nature.com/articles/s41561-023-01237-9
discussed at: https://www.facebook.com/groups/arcticnews/posts/10160935394954679

• Feedbacks

• Climate Reanalyzer - Daily 2-meter Air Temperature

• NOAA - Sea Surface Temperature (SST) Contour Charts

• NOAA - Global Monitoring Laboratory - Barrow, Alaska

• Feedbacks in the Arctic

• Record high North Atlantic sea surface temperature

• NASA Worldview

• Copernicus news release - 2023 Canada wildfires emissions have already doubled previous annual record (August 3, 2023)
https://atmosphere.copernicus.eu/2023-canada-wildfires-emissions-have-already-doubled-previous-annual-record

• Warning of mass extinction of species, including humans, within one decade

• Cold freshwater lid on North Atlantic





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Thursday, July 27, 2023

Record high North Atlantic sea surface temperature

On July 25, 2023, the North Atlantic sea surface reached a record high temperature of 24.9°C. The previous record was in early September 2022, when the temperature peaked at 24.89°C, according to NOAA scientist Xungang Yin and as illustrated by the image below. 

In previous years, a La Niña was suppressing temperatures, whereas El Niño is now pushing up temperatures. Arctic sea ice typically reaches its minimum extent about half September. We are facing huge sea ice loss over the coming weeks.

Temperatures are very high (and rising) and the following eight points contribute to this rise:

1. Emissions are high and greenhouse gas levels keep rising, and this is increasing Earth's Energy Imbalance. Oceans take up 89% of the extra heat.

2. El Niño is pushing up temperatures, whereas in previous years La Niña was suppressing temperatures. Moving from the bottom of a La Niña to the peak of a strong El Niño could make a difference of more than half a degree Celsius, as discussed in an earlier post.

In February 2016, when there was a strong El Niño, the temperature on land was 3.28°C (5.904°F) hotter than 1880-1896, and 3.68°C (6.624°F) hotter than February 1880 on land. Note that 1880-1896 is not pre-industrial, the difference will be even larger when using a genuinely pre-industrial base.

The above image, from an earlier post discussing extreme heat stress, adds a poignant punchline: Looking at global averages over long periods is a diversion, peak temperature rise is the killer!

[ click on images to enlarge ]
3. Sunspots in June 2023 were more than twice as high in number as predicted, as illustrated by the image on the right, from an earlier post and adapted from NOAA.

If this trend continues, the rise in sunspots forcing from May 2020 to July 2025 may well make a global temperature difference of more than 0.25°C, a recent analysis found.

4. A submarine volcano eruption near Tonga in January 2022 did add a huge amount of water vapor to the atmosphere, as discussed in an earlier post and also at facebook.

Since water vapor is a potent greenhouse gas, this further contributes to speeding up the temperature rise. A 2023 study calculates that the eruption will have a warming effect of 0.12 Watts/m² over the next few years.

5. Aerosol changes are also contributing to the temperature rise, such as less Sahara dust than usual and less sulfur aerosols that are co-emitted with fossil fuel combustion, which previously masked the full impact of greenhouse gases.

6. The Jet Stream is getting increasingly deformed as the temperature difference between the Arctic and the Tropics narrows, and this can strongly increase the intensity, duration and frequency of extreme weather events in the Northern Hemisphere. 

The image on the right shows North Atlantic sea surface temperatures as much as 8.2°C or 14.7°F higher than 1981-2011 (green circle) on July 24, 2023. The image also shows that the Jet Stream is very deformed and features many circular patterns that contribute to stronger heating up of the North Atlantic, especially along the path of the Gulf Stream where the Jet Stream has a strong presence.

Deformation of the Jet Stream can also lead to stronger heatwaves on land that extend over the Arctic Ocean, which in turn can also strongly heat up the water of rivers that end in the Arctic Ocean. The image on the right shows huge amounts of heat surrounding Arctic sea ice and also shows that on July 28, 2023, the sea surface was as much as 19.7°C or 35.4°F hotter than 1981-2011 at an area where the Ob River meets the Kara Sea (green circle).

7. AMOC (the Atlantic meridional overturning circulation) is slowing down, further contributing to more hot water accumulating in the North Atlantic. Instead of reaching the Arctic Ocean gradually, a huge part of this heat that is now accumulating in the
North Atlantic may abruptly be pushed into the Arctic Ocean by strong storms that gain strength as the Jet Stream gets increasingly deformed. This danger grows as more ocean heat is accumulating in the North Atlantic and this situation threatens to cause huge eruptions of methane from the seafloor. 

8. Increased stratification, as temperatures rise, combines with increased meltwater and with stronger evaporation over the North Atlantic and stronger precipitation further down the path of the Gulf Stream. This threatens to result in the formation of a freshwater lid on top of the North Atlantic, enabling more hot water to flow underneath this lid into the Arctic Ocean, further increasing the methane threat.


Arctic reaches record high air temperature

The Arctic reached a record high 2-meter air temperature of 5.81°C on July 27, 2023, almost 2°C higher than the daily mean for the period 1979-2000, as illustrated by the image below. Arctic sea ice typically reaches its minimum extent half September, when the temperature in the Arctic falls below 0°C and water at the surface starts refreezing. 


One danger is that, as more heat is reaching sediments at the seafloor of the Arctic Ocean, hydrates will be destabilized, resulting in eruption of huge amounts of methane from the seafloor.

As sea ice melts away, less sunlight gets reflected back into space, so more heat will reach the Arctic ocean and heat up the water, as discussed at the albedo page.

Furthermore, Arctic sea ice is already very thin, as illustrated by the image on the right. The thinner the sea ice, the less heat can be consumed in the process of melting the ice, as discussed at the latent heat page.

These are just three out of numerous developments that could unfold in the Arctic soon, such as tipping points getting crossed and feedbacks starting to kick in with greater ferocity, as discussed in an earlier post.

Latent heat loss, feedback #14 on the Feedbacks page

Feedbacks

Syee Weldeab et al., in a 2022 study, looked at the early part (128,000 to 125,000 years ago) of the penultimate interglacial, the Eemian, when meltwater from Greenland caused a weakening of the Atlantic meridional overturning circulation (AMOC). “What happens when you put a large amount of fresh water into the North Atlantic is basically it disturbs ocean circulation and reduces the advection of cold water into the intermediate depth of the tropical Atlantic, and as a result warms the waters at this depth,” he said. “We show a hitherto undocumented and remarkably large warming of water at intermediate depths, exhibiting a temperature increase of 6.7°C from the average background value,” Weldeab said.

Weldeab and colleagues used carbon isotopes (13C/12C) in the shells of microorganisms to uncover the fingerprint of methane release and methane oxidation across the water column. “This is one of several amplifying climatic feedback processes where a warming climate caused accelerated ice sheet melting,” he said. “The meltwater weakened the ocean circulation and, as a consequence, the waters at intermediate depth warmed significantly, leading to destabilization of shallow subsurface methane hydrates and release of methane, a potent greenhouse gas.”

Furthermore, more methane over the Arctic would push up temperatures locally over the Arctic Ocean as well as over permafrost on land. A 2020 study by Turetsky et al. found that Arctic permafrost thaw plays a greater role in climate change than previously estimated.

Ominously, some very high methane levels were recorded recently at Barrow, Alaska, as illustrated by the NOAA image below.
Further feedbacks can make the situation even more threatening. As an example, dissolved oxygen in oceans decreases as the temperature rises, further pushing up the temperature rise, as discussed, e.g., in a 2022 study by Jitao Chen et al. As the temperature rises, soil moisture content decreases, further pushing up temperatures, as discussed in an earlier post.

Conclusion

The situation is dire and is getting more dire every day, which calls for a Climate Emergency Declaration and implementation of comprehensive and effective action, as described in the Climate Plan with an update at Transforming Society.


Links

• N. Atlantic ocean temperature sets record high: US agency

• Nullschool
https://earth.nullschool.net

• Climate Reanalyzer - sea surface temperature
https://climatereanalyzer.org/clim/sst_daily

• Copernicus
https://climate.copernicus.eu

• University of Bremen - Arctic sea ice
https://seaice.uni-bremen.de/start

• A Prehistoric Climate Feedback Loop - Paleoclimatologist uncovers an ancient climate feedback loop that accelerated the effects of Earth's last warming episode (news release)
Evidence for massive methane hydrate destabilization during the penultimate interglacial warming - by Syee Weldeab et al. (study, 2022)

• Marine anoxia linked to abrupt global warming during Earth’s penultimate icehouse - by Jitao Chen et al. (2022)

• Carbon release through abrupt permafrost thaw - by Merritt Turetsky et al. (2020)
• NOAA - Global Monitoring Laboratory - Barrow, Alaska
https://gml.noaa.gov/dv/iadv/graph.php?code=BRW&program=ccgg&type=ts


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

• Will there be Arctic sea ice left in September 2023?
• Dire situation gets more dire every day
https://arctic-news.blogspot.com/2023/07/dire-situation-gets-more-dire-every-day.html

• Transforming Society
https://arctic-news.blogspot.com/2022/10/transforming-society.html

• Climate Emergency Declaration
https://arctic-news.blogspot.com/p/climate-emergency-declaration.html





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