Saturday, July 23, 2022

Arctic sea ice July 2022

Blue Ocean Event

[ from Blue Ocean Event ]
A Blue Ocean Event occurs when virtually all sea ice disappears and the surface color changes from white (sea ice) to blue (ocean). According to many, a Blue Ocean Event starts once Arctic sea ice extent falls below 1 million km².

The image on the right shows a trend pointing at zero Arctic sea ice volume by September 2027.

Note that the volume data in the image are averages for the month September ⁠— the minimum for each year is even lower. Furthermore, since zero volume implies zero extent, this indicates that a Blue Ocean Event (extent below 1 million km²) could happen well before 2027.

Sea ice extent

The image below, adapted from NSIDC, shows the extent of Arctic sea ice on July 26, 2022. 
[ click on images to enlarge ]

The extent of Arctic sea ice was among the lowest on record for the time of year on July 26, 2022. Furthermore, Antarctic sea ice extent is currently at a record low for the time of year, as illustrated by the image below, adapted from Vishop and showing the situation up to July 27, 2022. 


As a result, global extent of sea ice is close to record low for the time of year, as illustrated by the image below, adapted from Vishop and showing the situation up to July 27, 2022. 


Both Vishop and NSIDC use 15% concentration as the threshold for including an area in calculations of sea ice extent. This makes it important to look at the concentration of the sea ice. 

Sea ice concentration

The image below, adapted from University of Bremen, shows Arctic sea ice concentration on July 22, 2022, with concentration in many areas close to the North Pole down to 0%. 


The image below, adapted from NSIDC, shows Arctic sea ice concentration on July 26, 2022, with very low concentration of sea ice visible close to the North Pole. 


Sea ice thickness

The Naval Research Laboratory one-month animation below shows Arctic sea ice thickness up to July 25, 2022, with 8 days of forecasts added. 


The combination image below shows the fall in Arctic sea ice thickness from June 8 through August 6, 2022.

[ click on images to enlarge ]
The above combination image shows that most sea ice on June 8 (left) was forecast to be over 2 meters thick, that most sea ice on July 8 (center) was forecast to be over 1 meter thick, and that most sea was forecast to be under 1 meter thick on August 6, 2022 (right).

While the fall in extent over this period wasn't as dramatic, due to the suppression of air temperatures by the current La Niña, note that the green and yellow colors where the sea ice on June 8 was more than 2.5 meters thick, north of Greenland and north of the Canadian Arctic Archipelago, have virtually disappeared in the August 6 forecast.

The above maps show a dramatic fall in sea ice thickness over a large area. This fall in thickness is mostly due to warm water from the Atlantic Ocean that is melting the sea ice hanging underneath the surface. This is where the sea ice constitutes the latent heat buffer, consuming incoming heat in the process of melting.

The above Naval Research Laboratory maps may be conservative. The NASA Worldview and University of Bremen images below indicate that Arctic sea ice may be even thinner than that, especially north of the North Pole. 

The NASA Worldview combination image below shows the sea ice north of the North Pole on July 22, 2022 (left), and on July 23, 2022 (right), indicating that at many places there is no sea ice left at all. Note that the view in many places is obscured due to clouds. 


The University of Bremen combination image below shows the difference in sea ice thickness between June 1, 2022, June 30, 2022, and July 22, 2022. The images at the center and on the right show large areas where sea ice is less than 20 cm thick, indicating that the latent heat buffer had already disappeared in June 2022,  as also discussed further below. 

[ click on images to enlarge ]
The NASA Worldview combination image below shows the sea ice north of Greenland on July 19, 2022 (top), and on July 22, 2022 (bottom), indicating that even at places where the sea ice once was the thickest, it can melt away rapidly. The mechanism behind this is that, as thick ice breaks off and fragments, it additionally gets heated up from the sides, and this further accelerates the melting as the sea ice breaks up further, into ever smaller pieces.


The image below was created with a screenshot of a July 26, 2022, NASA Worldview satellite image, with the Earth at Night layer activated and brightness and contrast enhanced, which enables a closer look to be taken through the clouds. The image shows very little sea ice near the North Pole. 


The image below, a screenshot of a July 26, 2022, NASA Worldview satellite image, further shows that there is little sea ice close to the North Pole. 


Conditions behind the danger

One reason why sea ice has fallen so much in thickness so close to the North Pole is that around the time of the June Solstice (June 22, 2022) the North Pole receives more insolation than anywhere else on Earth.

Around this time of year, the sunlight has less distance to travel through the thinner atmosphere over the Arctic, so less sunlight gets absorbed or scattered before reaching the surface. In addition, the high angle of the Sun produces long days and sunlight is concentrated over a smaller area. Above the Arctic Circle, the Sun does not set at this time of year, so solar radiation continues all day and night.


How much sunlight does reach the surface further depends on weather conditions such as clouds and how much heat gets pushed by the wind toward the North Pole. As temperatures have risen over the years, the Jet Stream has become more deformed, increasing the chance that heatwaves over land extend over the Arctic Ocean. Deformation of the Jet Stream can also lead to increasingly strong winds speeding up ocean currents that can abruptly push huge amounts of ocean heat into the Arctic ocean, as further discussed below. For more background, also see the feedbacks page. 

Ocean heat

On July 19, 2022, the sea surface was as warm as 1.8°C or 35.2°F north of Greenland, as the nullschool.net image below shows. 


The above image also shows how cold water (blue) flows down to the east of Greenland, while warm water (green) flows off the west coast of Norway toward to Arctic Ocean, diving under the sea ice north of Svalbard and reaching areas north of Greenland where sea surface temperatures rise above freezing point. 

Of the extra heat from Earth's energy imbalance, about 93% ends up in the ocean as increasing ocean heat content (see image below), 3% goes into melting ice, 4% goes into raising temperatures of land and melting permafrost, and less than 1% remains in the atmosphere, as discussed in an earlier post.

[ from earlier post ]

Sea ice has disappeared in the Bering Strait, in part due to warm water from rivers in Alaska, as illustrated by the NOAA image below, which shows sea surface temperatures as high as 18.6°C or 65.48°F.


On July 19, 2022, the sea surface temperature anomaly from 1981-2011 in the Arctic Ocean was as high as 14.0°C or 25.2°F (at green circle), as illustrated by the screenshot below of a nullschool.net image (with text added). In 1981-2011, the sea surface temperature at this spot (at the green circle in the Kara Sea) at this time of year was around freezing point.


The above image also shows a distorted Jet Stream (at 250 hPa) moving over the Arctic ocean, instead of circumventing the Arctic and thus keeping heat out of the Arctic and keeping cold inside the Arctic, as it used to be.  


The above NOAA image illustrates how the Gulf Stream is pushing warm water toward the Arctic, with sea surface temperatures in the North Atlantic reaching as high as 32.6°C or 90.68°F on July 23, 2022.

Latent heat

Latent heat is heat that is (less and less) going into melting the sea ice. The reason this heat is called latent (hidden) heat, is that it doesn't raise the temperature of the water, but instead gets consumed in the process of melting the ice. Latent heat is energy associated with a phase change, such as the energy consumed when solid ice turns into water (i.e. melting). During a phase change, the temperature remains constant. Sea ice acts as a buffer that absorbs heat, while keeping the temperature at zero degrees Celsius. As long as there is sea ice in the water, this sea ice will keep absorbing heat, so the temperature doesn't rise at the sea surface. The amount of energy absorbed by melting ice is as much as it takes to heat an equivalent mass of water from zero to 80°C.


Once most of the sea ice that was hanging underneath the surface is gone, further heat will still keep moving underneath the sea ice from the Atlantic Ocean and - to a lesser extent - from the Pacific Ocean into the Arctic Ocean. Without the latent heat buffer, this heat must go elsewhere, i.e. it will typically raise the temperature of the water. The atmosphere will also warm up faster. More evaporation will occur once the sea ice is gone, further warming up the atmosphere.

A 2019 analysis concludes that the latent heat tipping point gets crossed when the sea surface temperature anomaly on the Northern Hemisphere gets higher than 1°C above 20th century's temperature and when there is little or no thick sea ice left. As the image below indicates, the temperature anomaly of 1°C above the 20th century average looks set to be crossed in the course of the year 2021.
As the Latent Heat Tipping Point gets crossed, there may still be a thin layer of ice at the surface, at least as long as air temperatures are low enough to keep it frozen and as long as strong winds haven't pushed the sea ice out of the Arctic Ocean. This thin layer of ice will still consume some ocean heat below the surface, but at the same time it acts as a seal, preventing heat from the Arctic Ocean to enter the atmosphere. Even if a lot of sea ice remains, the situation is dangerous, if not even more dangerous. The continuing La Niña could cause a lot of thin sea ice to remain at the surface of the Arctic Ocean this year. The more sea ice remains, the less ocean heat can be transferred from the Arctic Ocean to the atmosphere over the Arctic Ocean, which means that more heat remains in the Arctic Ocean.

One huge danger is that, as the buffer disappears that until now has consumed huge amounts of ocean heat, more heat will reach methane hydrates at the seafloor of the Arctic Ocean, causing them to get destabilized and resulting in releases of methane from these hydrates and from free gas underneath that was previously sealed by the hydrates.

As the latent heat buffer of the sea ice underneath the surface disappears, more of this heat could then reach sediments at the seafloor of the Arctic Ocean, threatening eruptions to occur of seafloor methane (from hydrates and from free gas underneath the hydrates). The methane could similarly push up temperatures dramatically over the Arctic, and globally over the next few years.

[ feedback #14: Latent Heat ]

The above 2014 image, from the feedbacks page, shows three of the numerous feedbacks that are accelerating warming in the Arctic. Feedback #1 is the albedo feedback. Feedback #14 refers to the loss of the Latent Heat Buffer and warming of the Arctic Ocean. Feedback #2 refers to methane releases.

Heatwaves look set to continue on the Northern Hemisphere, extending heat over the Arctic Ocean and thus affecting Arctic sea ice from above, while warm water from rivers will cause more melting at the surface, and while rising ocean heat will continue to cause more melting of the ice underneath the surface. If this continues, we can expect a new record low for sea ice in September 2022 and the joint loss of the latent heat buffer and the loss of albedo could push up temperatures dramatically over the Arctic, while the additional methane could similarly push up temperatures dramatically over the Arctic, and globally over the next few years.

[ The Buffer has gone, feedback #14 on the Feedbacks page ]
As discussed at the albedo page and the feedbacks page, albedo change, loss of the latent heat buffer and changes to the Jet Stream are important feedbacks. 


The above image, adapted from an ECMWF.int forecast for July 29, 2022, 12 UTC, run at that time, shows virtually no snow and ice cover over land except Greenland. The image also shows the difference such cover or the lack thereof makes in albedo. 

[ click on images to enlarge ]
The above image, adapted from NOAA Coral Bleaching Heat Stress Monitoring, shows expected coral bleaching heat stress for August to November 2022. The image on the right shows that coral bleaching alert level 2 was reached in the Barents Sea (green circle) on July 29, 2022, while a distorted Jet Stream is pushing warm, salty water from the Atlantic Ocean into the Arctic Ocean. 

A 2022 study of the Blob, a warm water area in the North Pacific that began in late 2013, concludes that the unusually warm waters were transported northward from further south. The researchers found that abnormally warm temperatures extended 1,000 meters (3,280 feet) below the surface.


The above image shows the Blob on July 24, 2022, with sea surface temperature anomalies as high as 10.5°C or 18.8°F on July 24, 2022. The North Pacific Current is visible, extending eastward from the coast of Japan.

Arctic-news has long (e.g. in this 2017 post) warned that changes to the Jet Stream can strengthen storms that can in turn cause a large amount of warm, salty water to abruptly move north and enter the Arctic Ocean from the Atlantic Ocean and trigger destabilization of methane hydrates at the seafloor of the Arctic Ocean, resulting in eruption of huge amounts of methane that could drive humans into extinction in a matter of years. 


Conclusion

In conclusion, temperatures could rise strongly in the Arctic soon, due to sea ice loss in combination with feedbacks and an upcoming El Niño coinciding with a peak in sunspots, with the potential to drive humans extinct as early as in 2025, while temperatures would continue to skyrocket in 2026, making it in many respects rather futile to speculate about what will happen beyond 2026. At the same time, the right thing to do now is to help avoid the worst things from happening, through comprehensive and effective action as described in the Climate Plan.


Links

• Blue Ocean Event
https://arctic-news.blogspot.com/p/blue-ocean-event.html

• National Snow and Ice Data Center (NSIDC)
https://nsidc.org

• Visualization Service of Horizontal scale Observations at Polar region (Vishop) 
https://ads.nipr.ac.jp/vishop/#/extent

• Naval Research Laboratory
https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/arctic.html

• University of Bremen
https://seaice.uni-bremen.de/databrowser

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

• NOAA - sea surface temperature

• Human Extinction by 2025? 


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Wednesday, July 13, 2022

Human Extinction by 2025?

Most important metric

Kevin Trenberth et al. suggest in a recent article that Earth's energy imbalance, defined as the absorbed solar radiation minus the net outgoing longwave radiation, is arguably the most important metric related to climate change. Of the extra heat from Earth's energy imbalance, about 93% ends up in the ocean as increasing ocean heat content (see image below), 3% goes into melting ice, 4% goes into raising temperatures of land and melting permafrost, and less than 1% remains in the atmosphere. 


One could also argue that the most important metric related to climate change is the monthly mean surface temperatures on land, as illustrated by the image below that was created with a July 16, 2022 screenshot from NASA customized analysis plots and shows that the February 2016 (land only) anomaly from 1886-1915 was 2.94°C or 5.292°F. 


Land only anomalies are important. After all, most people live on land and humans will likely go extinct with a rise of 3°C above pre-industrial, as illustrated by the image below, from an analysis in earlier post.


Note that in the above plot, anomalies are measured versus 1886-1915, which isn't pre-industrial. The image raises questions as to what the temperature rise would look like when using a much earlier base, and how much temperatures could rise over the next few years.  

Potential for temperature rise on land

The image below shows land only surface temperature anomalies, similar to the above image but further adjusted by almost a degree to reflect a pre-industrial base, ocean air temperatures and higher polar anomalies, as discussed at the pre-industrial page.


The image features two trends. The blue trend is based on January 1880-June 2022 land only data and shows the potential for 3°C to be crossed on land and to drive humans into extinction by 2025. The green trend is based on January 2010-June 2022 land only data and shows the potential for 5°C to be crossed on land by 2026, which will likely drive most life on land into extinction. 

A temperature rise of 3°C would likely stop all activities by humans, including their emissions, yet temperatures could keep rising.

Could temperatures keep rising?

In the video below, Guy McPherson discusses Abrupt, Irreversible Climate Change to Cause Planetary Extinction.




Concentrations of greenhouse gases in the atmosphere constitute yet another important metric related to climate change. Carbon dioxide at Mauna Loa in June 2022 was 420.99 ppm, a joint record high with May 2022, as illustrated by the above image. Methane and nitrous oxide concentrations are also at record high since 1750, as illustrated by the image on the right, from an earlier post. 

Greenhouse gas concentrations this high are likely to keep adding ocean heat for some time, causing further melting of sea ice, etc.

All these metrics are important, including Earth's energy imbalance, concentrations of greenhouse gases in the atmosphere, and monthly land only surface temperature anomalies.

Greenhouse gases remain in the atmosphere for many years, so even if emissions by people's activities stop now, concentrations of greenhouse gases that have a long lifetime are unlikely to fall much over the next few years, while there would be additional emissions (such as carbon monoxide) from decomposing biomass, forest fires and waste fires globally that would also make it hard for concentrations of shorter-lived methane to fall, as also discussed here.

We're also moving into a new El Niño, as illustrated by the image on the right. The difference between the top of El Niño and the bottom of La Niña could be more than half a degree Celsius, as the NOAA image below shows. The upcoming El Niño may well coincide with a peak in sunspots in 2025, further pushing up temperatures, as also discussed in the post Cataclysmic Alignment, which also mentions a recent study that warns that the combined impact of aerosols and nitrogen fertilizers can contribute much more strongly than previously thought to the formation of cirrus clouds that contribute to global warming. 


The resulting heatwaves and fires could trigger massive blackouts and, as civilization grinds to a halt, this could cause much of the sulfate masking effect to fall away almost instantly, resulting in further acceleration of the temperature rise. 

All this looks set to contribute to keep temperatures rising for years to come, with the danger of increasing ocean temperatures to the point where there would be massive eruptions of seafloor methane that contribute to the clouds tipping point at 1200 ppm CO₂e to be crossed, which in itself would push up temperatures by a further 8°C and cause rapid extinction of most life on Earth, as this 2019 analysis and this and this more recent analyses warn.

[ from earlier post ]

The clouds tipping point could be crossed as a result of seafloor methane releases. There is potential for such releases, given the rising ocean heat and the vast amounts of methane present in vulnerable sediments at the seafloor of the Arctic Ocean, as discussed in posts such as this one. If methane concentrations would increase in line with the trend in the above mage, i.e. methane reaching 780 ppm CO₂e by 2028 using a 1-year GWP of 200, this plus a concentration of carbon dioxide of 420.99 ppm as in the image further above would suffice to cause the clouds tipping point to be crossed. When adding further forcers, this could happen even earlier.

[ click on images to enlarge ]
Altogether, the global temperature could rise by more than 18°C above pre-industrial within a few years, as also discussed at the Extinction page. Even the longer-term outlook doesn't look promising. A 2020 analysis by Jorgen Randers et al. points out that, even if all greenhouse gas emissions by people could stop immediately and even if the temperature anomaly could fall to 0.5°C above pre-industrial, greenhouse gas levels would start rising again after 2150 and keep rising for centuries to come, while, as discussed in an earlier post, a 2016 analysis by Ganapolski et al. suggests that even moderate anthropogenic cumulative carbon dioxide emissions would cause an absence of the snow and ice cover in the next Milankovitch cycle, so there would be no buffer at the next peak in insolation, and temperatures would continue to rise, making the absence of snow and ice a permanent loss for millennia to come.

Conclusion

In an earlier post, the following question was also discussed: Could temperatures keep rising? This post concludes that surface temperatures on land could rise strongly over the next few years and drive humans into extinction as early as in 2025. Temperatures could continue to rise afterwards and drive most life on Earth into extinction soon thereafter, making it the more important to do the right thing now and help avoid the worst from happening, through comprehensive and effective action as described in the Climate Plan.

Our duty to support local people's courts that administer local feebates 

The disregard for science and democracy by those in power has now become so apparent and appalling that we, the people, must agree that the best way forward is to institute Local People's Courts in which randomly-chosen residents administer local feebates, as a superior form of democracy and decision-making.

Elections do allow people to participate in decisions regarding their own lives and future, but elections only give people a single choice every few years between representatives who then take decisions of importance for them. While this can be regarded as a shallow form of democracy, it is now sufficiently clear that elections effectively remove people's participation in such decisions and deteriorate the outlook and future for people and the environment locally and globally.

Residents should participate in decisions regarding their own lives and environment by supporting Local People's Courts that administer local feebates, with fees added to the sales price of polluting products and to rates on degraded land, and with revenue of fees used to fund support for improvements, such as through rebates on cleaner products sold locally or rebates on local rates on improved land. Local People's Courts can best ensure that choices regarding percentages and eligibility of fees and rebates are science-based, while feebates leave the choice as to what to buy or sell to individuals.

[ image from earlier post ]


Links

• A perspective on climate change from Earth's energy imbalance - by Kevin Trenberth et al. 
https://iopscience.iop.org/article/10.1088/2752-5295/ac6f74

• Another Record: Ocean Warming Continues through 2021 despite La Niña Conditions - by Lijing Cheng et al. 
https://link.springer.com/article/10.1007/s00376-022-1461-3

• Improved Quantification of the Rate of Ocean Warming - by Lijing Cheng et al. 
https://journals.ametsoc.org/view/journals/clim/35/14/JCLI-D-21-0895.1.xml

• NASA - GISS Surface Temperature Analysis 


• An earth system model shows self-sustained thawing of permafrost even if all man-made GHG emissions stop in 2020 - by Jorgen Randers et al.
https://www.nature.com/articles/s41598-020-75481-z

• Could temperatures keep rising?

• Critical insolation–CO2 relation for diagnosing past and future glacial inception - by Andrey Ganapolski et al. (2016)
https://www.nature.com/articles/nature16494

• NOAA - Trends in Atmospheric Carbon Dioxide - Mauna Loa, Hawaii 
https://gml.noaa.gov/ccgg/trends/graph.html

• Will COP26 in Glasgow deliver?
• Impact of interannual and multidecadal trends on methane-climate feedbacks and sensitivity - by Chin-Hsien Cheng et al.
https://www.nature.com/articles/s41467-022-31345-w

• NOAA - ENSO: Recent Evolution, Current Status and Predictions
https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf

• NOAA - Monthly Temperature Anomalies Versus El Niño

• Cataclysmic Alignment 
https://arctic-news.blogspot.com/2022/06/cataclysmic-alignment.html

• Sunspots
https://arctic-news.blogspot.com/p/sunspots.html

• Methane rise is accelerating
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Monday, June 20, 2022

Arctic sea ice June 2022 - why the situation is so dangerous

Sea Ice Extent


Arctic sea ice extent has fallen strongly in June 2022. On June 22, 2022, Arctic sea ice extent was among the lowest on record for the time of year, as illustrated by the above image, adapted from the National Snow and Ice Data Center (NSIDC Chartic). 

The image below, from an animation by Zachary Labe, shows Arctic sea ice extent up to June 20, 2022, based on Vishop data. The yellow line is the year 2022. The white line shows extent for the year 2012, when it reached a record minimum in September. The blue line shows extent the year 2020, when the minimum in September was second lowest.
 

The image below, adapted from Vishop, shows that on June 23, 2022, global sea ice extent was at a record low for the time of year.


La Niña

[ adapted from NOAA - click on images to enlarge ]
The fact that sea ice is so low for the time of the year is the more striking as we are currently in the depths of a persistent La Niña, which suppresses the temperature rise.

El Niños typically occur every 3 to 5 years, according to NOAA and as also illustrated by the NOAA image below, so the upcoming El Niño can be expected to occur soon.

The NOAA image below indicates that going from the bottom of a La Niña to the peak of an El Niño could make a difference of more than half a degree Celsius (0.5°C or 0.9°F).


Furthermore, the rise in sunspots from May 2020 to July 2025 could make a difference of some 0.15°C (0.27°F). The next El Niño looks set to line up with a high peak in sunspots, in a cataclysmic alignment that could push up the temperature enough to cause dramatic sea ice loss in the Arctic, resulting in runaway temperature rise by 2026.

Multi-year Sea Ice

The NSIDC compilation below illustrates how much multi-year sea ice has already declined over the years. The top panel shows the age of Arctic sea ice for the March 12 to 18 period in (a) 1985 and (b) 2022. The oldest ice, greater than 4 years old, is in red. Plot (c) shows the timeseries from 1985 through 2022 of percent cover of the Arctic Ocean domain (inset, purple region) by different sea ice ages during the March 12 to 18 period.


Sea Ice Volume

On June 18, 2022, Arctic sea ice volume was among the lowest on record for the time of year, as illustrated by the image below, adapted from Polarportal.


A Blue Ocean Event occurs when virtually all sea ice disappears and the surface color changes from white (sea ice) to blue (ocean). According to many, a Blue Ocean Event starts once Arctic sea ice extent falls below 1 million km².

The image on the right shows a trend pointing at zero Arctic sea ice volume by September 2027.

Note that the volume data in the image are averages for the month September ⁠— the minimum for each year is even lower. Furthermore, since zero volume implies zero extent, this indicates that a Blue Ocean Event (extent below 1 million km²) could happen well before 2027.

Sea Ice Thickness

The Naval Research Laboratory one-month animation below shows Arctic sea ice thickness up to June 18, 2022, with 8 days of forecasts added.


The above animation shows a dramatic fall in sea ice thickness over a large area, while sea ice is disappearing altogether in some places. This fall in thickness is mostly due to warm water from the Atlantic Ocean that is melting the sea ice hanging underneath the surface. This is where the sea ice constitutes the latent heat buffer, consuming incoming heat in the process of melting.

The University of Bremen combination image below shows the difference in sea ice thickness between June 1 and June 30, 2022. The image on the right shows a large areas where sea ice is less than 20 cm thick.


The NASA Worldview image below shows the situation on June 24, 2022. Plenty of water is showing up as close as 200 km to the North Pole.


Also view the NASA Worldview animation comparing sea ice at June 24 and 25, 2022 at facebook. 

Ocean Heat and decline of the Latent Heat Buffer


Ocean heat keeps rising; in 2021, despite La Niña conditions, ocean heat reached yet another record high, as illustrated by the above image, from an earlier post.

A 2019 analysis concludes that the latent heat tipping point gets crossed when the sea surface temperature anomaly on the Northern Hemisphere gets higher than 1°C above 20th century's temperature and when there is little or no thick sea ice left. As the image below indicates, the temperature anomaly of 1°C above the 20th century average looks set to be crossed in the course of the year 2021.


Close to the coast of Siberia, where much of the sea ice has disappeared altogether, the decline is due for a large part to warm water from rivers flowing into the Arctic Ocean. 


Sea ice has also disappeared altogether in the Bering Strait, for a great part due to warm water from rivers in Alaska, especially the Yukon River, the Kuskokwim River and the Copper River, as illustrated by the above NOAA image, which shows sea surface temperatures as high as 15.6°C or 60.08°F.


On June 10, 2022, the sea surface temperature anomaly from 1981-2011 in the Bering Strait was as high as 15.5°C or 27.9°F (at green circle), illustrated by the above nullschool.net image. In 1981-2011, the Bering Strait was still largely frozen at this time of year.

The NOAA image below illustrates how the Gulf Stream is pushing warm water toward the Arctic, with sea surface temperatures in the North Atlantic reaching as high as 32.1°C or 89.78°F on June 19, 2022. 


Latent heat is heat that is (less and less) going into melting the sea ice. The reason this heat is called latent (hidden) heat, is that it doesn't raise the temperature of the water, but instead gets consumed in the process of melting the ice. Latent heat is energy associated with a phase change, such as the energy consumed when solid ice turns into water (i.e. melting). During a phase change, the temperature remains constant. Sea ice acts as a buffer that absorbs heat, while keeping the temperature at zero degrees Celsius. As long as there is sea ice in the water, this sea ice will keep absorbing heat, so the temperature doesn't rise at the sea surface. The amount of energy absorbed by melting ice is as much as it takes to heat an equivalent mass of water from zero to 80°C.


The combination image below illustrates how much ocean heat is entering the Arctic Ocean from the Atlantic Ocean, heating up the sea ice from below.

The left panel shows the depth of the Arctic Ocean, with darker blue indicating greater depth.

In the right panel, the light blue, green and yellow colors indicate the thickest ice, located in the shallow waters off the coasts of North America and Greenland. The darker blue colors indicate where much of the sea ice has melted away, from below, as also illustrated by the one-month animation below showing sea ice thickness up to June 22, 2022, with an added 8 days of forecasts. The white color indicates where the sea ice has melted away entirely, e.g. in the Bering Strait and north of Siberia, mainly due to warm water from rivers entering the Arctic Ocean.


Once most of the sea ice that was hanging underneath the surface is gone, further heat will still keep moving underneath the sea ice from the Atlantic Ocean and - to a lesser extent - from the Atlantic Ocean into the Arctic Ocean. Without the latent heat buffer, this heat must go elsewhere, i.e. it will typically raise the temperature of the water. The atmosphere will also warm up faster. More evaporation will occur once the sea ice is gone, further warming up the atmosphere.

As the Latent Heat Tipping Point gets crossed, there may still be a thin layer of ice at the surface, at least as long as air temperatures are low enough to keep it frozen and as long as strong winds haven't pushed the sea ice out of the Arctic Ocean. This thin layer of ice will still consume some ocean heat below the surface, but at the same time it acts as a seal, preventing heat from the Arctic Ocean to enter the atmosphere. Even if a lot of sea ice remains, the situation is dangerous, if not even more dangerous. The continuing La Niña could cause a lot of thin sea ice to remain at the surface of the Arctic Ocean this year. The more sea ice remains, the less ocean heat can be transferred from the Arctic Ocean to the atmosphere over the Arctic Ocean, which means that more heat remains in the Arctic Ocean.

One huge danger is that, as the buffer disappears that until now has consumed huge amounts of ocean heat, more heat will reach methane hydrates at the seafloor of the Arctic Ocean, causing them to get destabilized and resulting in releases of methane from these hydrates and from free gas underneath that was previously sealed by the hydrates.

As the latent heat buffer of the sea ice underneath the surface disappears, more of this heat could then reach sediments at the seafloor of the Arctic Ocean, threatening eruptions to occur of seafloor methane (from hydrates and from free gas underneath the hydrates). The methane could similarly push up temperatures dramatically over the Arctic, and globally over the next few years. 

[ feedback #14: Latent Heat ]

The above 2014 image, from the feedbacks page, shows three of the numerous feedbacks that are accelerating warming in the Arctic. Feedback #1 is the albedo feedback. Feedback #14 refers to the loss of the Latent Heat Buffer and warming of the Arctic Ocean. Feedback #2 refers to methane releases. 

Heatwaves look set to continue on the Northern Hemisphere, extending heat over the Arctic Ocean and thus affecting Arctic sea ice from above, while warm water from rivers will cause more melting at the surface, and while rising ocean heat will continue to cause more melting of the ice underneath the surface. If this continues, we can expect a new record low for sea ice in September 2022 and the joint loss of the latent heat buffer and the loss of albedo could push up temperatures dramatically over the Arctic, while the additional methane could similarly push up temperatures dramatically over the Arctic, and globally over the next few years. 

[ The Buffer has gone, feedback #14 on the Feedbacks page ]

Conclusion

In conclusion, temperatures could rise strongly in the Arctic soon, due to sea ice loss in combination with an upcoming El Niño and a peak in sunspots, with the potential to drive humans extinct as early as in 2025, while temperatures would continue to skyrocket in 2026, making it in many respects rather futile to speculate about what will happen beyond 2026. At the same time, the right thing to do now is to help avoid the worst things from happening, through comprehensive and effective action as described in the Climate Plan.

• Blue Ocean Event 

• Polarportal

• Naval Research Laboratory

• University of Bremen

• NASA Worldview satellite

• NOAA - sea surface temperature
https://www.ospo.noaa.gov/Products/ocean/sst/contour/index.html

• nullschool
https://earth.nullschool.net

• Albedo, latent heat, insolation and more

• Latent Heat Buffer

• Feedbacks in the Arctic

• Extinction
https://arctic-news.blogspot.com/p/extinction.html

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




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