Showing posts with label latent heat. Show all posts
Showing posts with label latent heat. Show all posts

Friday, February 2, 2024

Blue Ocean Event 2024?

How likely is an Arctic Blue Ocean Event (BOE) to occur in 2024 or even a Double BOE? The image below is alarming. 


The highest daily sea surface temperatures on record (going back to 1981) were reached in February 2024, even higher than the peaks in 2023. Even higher temperatures may be reached over soon, in March 2024 and April 2024.

As the above image shows, the highest temperatures for the year are typically reached in March. This was the case for the previous years on record, except for 2023 when the current El Niño started to emerge and when the highest peak for the year occurred in August. According to NOAA, the majority of models indicate that this El Niño will persist through March-May 2024. 

Antarctic sea ice extent typically reaches an annual minimum end February, while Arctic sea ice extent typically reaches an annual minimum in September, after a steep decline resulting from more sunlight reaching higher latitudes North and ocean heat reaching a second peak in August.   

Ominously, daily surface air temperatures in the Southern Hemisphere exceeded 17°C recently, something that never happened before in the record going back to 1981. Antarctic sea ice extent typically reaches an annual minimum end February. Loss of sea ice acts as a self-reinforcing feedback loop, accelerating the temperature rise. The daily surface air temperature in the Southern Hemisphere was 17.005°C on Feb 1, 2024, following a peak of 17.01°C on Jan 31, 2024.


Higher temperatures can cause sea ice to melt, even out of season

As illustrated by the image below, adapted from Pidwirny, sunlight does not reach the North Pole until the March Equinox. From that time on, insolation rises steeply. Around the June Solstice, more sunlight reaches the North Pole than anywhere else on Earth. In the image below, insolation is calculated taking into account the combined effects of angle of incidence and day length duration. 

The conclusion is that ocean heat is the main reason why melting of Arctic sea ice can occur early in the year. More specifically, the narrowing of the temperature difference between the Arctic and the Tropics can at times cause strong wind to be present along the path of the Gulf Stream. Rising ocean heat combined with strong wind can cause heat to move abruptly toward the Arctic Ocean, causing sea ice to fall in extent. 

Such an event is illustrated by the image below, adapted from NSIDC. The image shows a drop in sea ice extent at the end of January 2024 (blue), a time of year when Arctic sea ice is still expected to increase in extent and to keep increasing in extent for some time to come (grey). In this case, strong wind may have caused a huge amount of ocean heat that is present in the North Atlantic to move abruptly toward the Arctic Ocean, as discussed in an earlier post

For the time of year, Arctic sea ice extent is currently still extensive, compared to earlier years, which is a reflection of more water vapor in the atmosphere and more precipitation. While sea ice extent is relatively large, sea ice volume is among the lowest of all years on record for the time of year, as illustrated by the image below. 

This indicates that Arctic sea ice is very thin. Ominously, the image below indicates that there is a huge area near the North Pole with very thin sea ice. 


Furthermore, much of the thicker sea ice is located off the east coast of Greenland, which means that this sea ice is likely to melt away quickly as more sunlight starts reaching the Northern Hemisphere and temperatures rise in line with seasonal changes (see the insolation image further above).


The North Atlantic sea surface temperature was 20.4°C on February 15, 2024, i.e. 0.6°C higher than on February 15, 2023.

High North Atlantic sea surface temperatures spell bad news for the Arctic, as much ocean heat gets pushed toward the Arctic from the North Atlantic. 

North Atlantic sea surface temperatures are just starting to heat up from their annual minimum and can be expected to rise strongly, in line with seasonal changes. 

[ click on images to enlarge ]
Ominously, a peak temperature of 25.4°C was reached on Aug.31, 2023, much higher than the peak in any of the preceding years dating back to 1981.

During the six months between the September Equinox and the March Equinox (see image further above), no sunlight is reaching the North Pole. 

Nonetheless, temperature anomalies in the Arctic are already extremely high, due to ocean heat that has entered the Arctic Ocean from the North Atlantic, as illustrated by the two maps on the right and the two maps on the right further below.

Northern Hemisphere Sea Surface Temperature Anomalies were as much as 12.6°C or 22.7°F higher than 1981-2011 on February 15, 2024, locarion marked by the green circle on the image below.


Feedbacks 

Slowing down of AMOC and cooling due to heavier melting of Greenland's ice is causing less ocean heat to reach the Arctic Ocean, while a huge amount of ocean heat is accumulating in the North Atlantic, as it did in 2023. A large part of this heat in the North Atlantic can also be present underneath the sea surface.

These developments occur at the same time as ocean stratification increases (as temperatures rise, see above images), as more freshwater enters the ocean (as a result of more meltwater and of runoff from land and from rivers), and as more evaporation takes place and more rain falls further down the path of the Gulf Stream, all of which can contribute to formation and growth of a cold, freshwater lid at the surface of the North Atlantic.

cold freshwater lid on North Atlantic ]

Furthermore, storms can get stronger as temperatures rise and as changes take place to the Jet Stream. Strong wind can temporarily speed up currents that carry huge amounts of ocean heat with them toward the Arctic Ocean, as discussed in earlier posts such as this one. Much of the ocean heat in the North Atlantic can therefore be pushed abruptly underneath this freshwater lid and flow into the Arctic Ocean. The image below shows that the Jet Stream reached speeds as high as 455 km/h or 283 mph north of Washington on February 18, 2024 03:00 UTC, with Instantaneous Wind Power Density as high as 387.5 kW/m².


The image below shows wind speed at 250 hPa on a background of sea surface temperature anomalies versus 1981-2011. 


The danger is that, due to strong wind along the path of the Gulf Stream, huge amounts of ocean heat will abruptly get pushed into the Arctic Ocean, with the influx of ocean heat causing destabilization of hydrates contained in sediments at the seafloor of the Arctic Ocean, resulting in eruptions of huge amounts of methane.

Changes to the Jet Stream and ocean heat accumulating in the North Atlantic Ocean are both consequences of the overall temperature rise. A distorted Jet Stream can cause an abrupt influx of ocean heat into the Arctic Ocean.

Such additional ocean heat, combined with a steep rise in insolation hitting the Arctic in April and May, may suffice to cause a Blue Ocean Event (BOE) to occur in 2024.

[ click on images to enlarge ]
The far North has the highest temperature anomalies, they can as high as 7.04°C, as the image on the right shows.

A BOE occurs when virtually all sea ice disappears and less than 1 million km² of sea ice remains. As the sea ice disappears, the surface color changes from white (sea ice) to blue (ocean) resulting in far more sunlight getting absorbed by the Arctic Ocean, instead of getting reflected back into space as was previously the case.

Albedo change constitutes a huge self-reinforcing feedback loop, i.e. the more sea ice disappears, the more sunlight gets absorbed by the Arctic Ocean, further accelerating sea ice melting. 

[ Albedo change, from the Albedo page ]

Next to the albedo loss, there is loss of the latent heat buffer constituted by the sea ice. Latent heat is energy associated with a phase change, such as the energy consumed when solid ice turns into water (i.e. melts). During a phase change, the temperature remains constant. Sea ice acts as a buffer that absorbs heat, while keeping the temperature at about 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 up an equivalent mass of water from zero to 80°C. 

Without the buffer constituted by thicker sea ice, an influx of ocean heat could destabilize hydrates contained in sediments at the seafloor of the Arctic Ocean, resulting in eruptions of huge amounts of methane.

[ click on images to enlarge ]
The above image illustrates these tipping points and Northern Hemisphere Ocean Temperature anomalies vs 1901-2000, created with NOAA data. Trends and tipping point estimates are added. The magenta trend is based on Jan.1880-Jan.2024 data and warns that the Seafloor Methane Tipping Point may be crossed in 2025. The red trend is based on Jan.2010-Jan.2024 data and better reflects variables such as El Niño, and it warns that the Seafloor Methane Tipping Point may be crossed in 2024. 


The above image, adapted from tropicaltidbits.com, shows a forecast for November 2024 of the 2-meter temperature anomaly in degrees Celsius, based on 1984-2009 model climatology. The anomalies are forecast to be very high for the Arctic Ocean.

Many additional feedbacks are active, such as changes to the Jet Stream and slowing down of AMOC, and they could speed up the crossing of such tipping points, as also discussed at the feedbacks page. The danger is that a cascade of events will unfold like a domino effect, leading to extinction of most species, including humans, as the image below warns. 

[ from earlier post - click on images to enlarge ]

Greenhouse gases rising

Meanwhile, concentrations of greenhouse gases keeps rising, as illustrated by the image below. 

The average daily carbon dioxide (CO₂) at Mauna Loa, Hawaii, was 426.21 ppm (parts per million) on February 4, 2024. The weekly average was 425.83 ppm. 

Critical is the rate of change, in particular the rapid rise in temperatures and greenhouse gas concentrations. To find higher CO₂ concentrations, one has to go back millions of years. 


A recent study concludes that: 
- A doubling of CO₂ is predicted to warm the planet a whopping 5°C to 8°C.
- The last time atmospheric CO₂ consistently reached today’s human-driven levels of 420 ppm was 14 million years ago.
- The hottest period was about 50 million years ago, when temperatures were as much as 12°C higher than today.

Climate Emergency Declaration

The situation is dire and the precautionary principle calls for rapid, comprehensive and effective action to reduce the damage and to improve the situation, as described in this 2022 post, where needed in combination with a Climate Emergency Declaration, as discussed at this group.



Links

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

• Climate Reanalyzer - Daily Sea Surface Temperature, World (60°S-60°N)
https://climatereanalyzer.org/clim/sst_daily

• Pidwirny, M. "Earth-Sun Relationships and Insolation". Fundamentals of Physical Geography, 2nd Edition (2006)
http://www.physicalgeography.net/fundamentals/6i.html

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

• NSIDC - Arctic sea ice extent
https://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph

• Polar Portal - Sea Ice Thickness and Volume
http://polarportal.dk/en/sea-ice-and-icebergs/sea-ice-thickness-and-volume

• University of Bremen - Arctic sea ice

• Scripps Institution of Oceanography at UC San Diego.

• Toward a Cenozoic history of atmospheric CO₂ - by The Cenozoic CO₂ Proxy Integration Project (CenCO₂PIP) Consortium






Tuesday, August 15, 2023

Two Tipping Points

The image below, adapted from Climate Reanalyzer, shows that the World Sea Surface Temperature (60°South - 60°North) was at a record high of 21.1°C or 69.98°F for the third day in a row on August 23, 2023. As the image also shows, sea surface temperatures over the past few months have been much higher for the time of year than in any other year on record. 

The image below shows why this recent sea surface temperature rise is so worrying. The image below is based on NASA data for monthly mean global surface temperature anomalies (open ocean) vs 1901-1930. The ochre trend, based on January 1900-July 2023 data, indicates that the latent heat tipping point was crossed in 2021 and the seafloor methane tipping point may be crossed by the end of 2033. Both trends extend into the future for 15 years, but the red trend is based on July 2008-July 2023 data and better reflects El Niño and other variables, and this red trend indicates that the latent heat tipping point was crossed in 2023 and the seafloor methane tipping point may be crossed later this year.

[ click on images to enlarge ]

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 wil do so at 4.18 J/g for every 1°C the temperature of the water rises. 

[ sea ice thickness, from earlier post ]
Loss of this buffer is linked to subsequent destabilization of methane hydrates. So, there are two tipping points that are linked, and the latent heat tipping point gets crossed in the Arctic before the seafloor methane tipping point gets reached.

The 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. The image on the right, from Uni of Bremen, shows that on July 25, 2023, there was virtually no Arctic sea ice left that was more than 30 cm thick. 

The latent heat tipping point is the point where Arctic sea ice loss is such that further incoming ocean heat that was previously consumed as Arctic sea ice melted, instead gets absorbed by the Arctic Ocean. 

[ sea surface temperature anomaly ]
The image on the right, adapted from nullschool.net, shows that on August 2, 2023, most of the Arctic Ocean was showing surface temperatures above the daily average during 1981-2011, indicating that the latent heat tipping point was reached. The latent heat tipping point is estimated to correspond with an ocean temperature anomaly of 1°C above the long term average, 1901-1930 on the above image.

The image underneath, also from nullschool.net, shows the situation on August 20, 2023, when temperatures at the North Pole had been above zero for more than a day and temperatures were forecast to go below zero only twice briefly afterwards, for the period up to August 24, 2023 19:00 UTC (which is as far as the forecast went at the time. 

[ surface temperature ]
This is a further indication that the latent heat tipping point has been reached and that no more heat can be consumed by sea ice melting.

How much sea ice is left? What does the sea ice look like, near the North Pole? Satellite images can give a good impression, but clouds can obscure the view. A clearer view can be obtained by comparing images over several days. 

An animation can reveal how much, or rather how little sea ice is left, and to what extent water of the Arctic Ocean is visible. 

[ Satellite view, click on images to enlarge ]
The animation on the right is made with four NASA Worldview images, showing the situation on August 11, 15, 16 and 19, 2023. 

The second tipping point, the seafloor methane tipping point, occurs as more heat reaches the seafloor where it 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, so the seafloor methane tipping point is estimated to correspond with a higher ocean temperature anomaly.

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 (image right) 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 further 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 get crossed when the ocean temperature anomaly on the Northern Hemisphere goes beyond 1.35°C above its long term average.

The Argo Float 7900549 compilation image below illustrates that the highest water temperatures in the Arctic Ocean can occur at a depth of approximately 100 meters. The image shows temperatures as high as 5°C at that altitude.


Stronger winds along the path of the Gulf Stream can at times speed up sea currents that travel underneath the surface. As a result, huge amounts of hot, salty water can travel from the Atlantic Ocean into the Arctic Ocean, abruptly pushing up temperatures and salinity levels at the bottom of the Arctic Ocean, which in many places is very shallow.


The above image shows details of Argo float 9701007, further illustrating the danger that heat can reach the seafloor. North of Norway, where the water is less than 400 m deep, temperatures higher than 5°C show up throughout the vertical water column, up to August 10, 2023, when temperatures above 11°C were recorded close to the sea surface. The colored inset also shows that greater mixing down of heat occurred from October to December 2022, as the sea ice started to return and seal off the surface, preventing heat transfer from ocean to atmosphere, as also discussed at FAQ #11.

Below is another image adapted from Climate Reanalyzer, showing that the sea surface temperature of the North Atlantic Ocean has for months been much higher for the time of year than it was in previous years on record. Eight causes behind this have been discussed in an earlier post. The image below shows the situation on August 28, 2023, with the North Atlantic sea surface temperature reaching a record high of 25.34°C or 77.61°F. 


The image below, adapted from NOAA, shows how the Gulf Stream is pushing ocean heat toward the Arctic Ocean, while sea surface temperatures show up as high as 33.6°C or 92.48°F on August 17, 2023. 


[ 2022 animation ]
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 similarly result in strong winds abruptly pushing a huge amount of heat through the Bering Strait into the Arctic Ocean. 

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.

The image below, adapted from Climate Reanalyzer, shows that the (2-meter) air temperature in the Arctic was 3.79°C on August 25, 2023, a record high for the time of year and 2.08°C higher than the 1979-2011 mean for that day.


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 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.

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

The most recent monthly methane average recorded at Barrow, Alaska, is above 2080 parts per billion.

In the video below, Guy McPherson describes the dire situation.


Climate Emergency Declaration

A catastrophe of unimaginable proportions is unfolding. Life is disappearing from Earth and runaway heating could destroy all life. 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

• Climate Reanalyzer - daily 2-meter air temperature
https://climatereanalyzer.org/clim/t2_daily

• NASA - GISS Surface Temperature Analysis
https://earth.nullschool.net

• NOAA - Barrow Atmospheric Baseline Observatory, United States
https://gml.noaa.gov/dv/iadv/graph.php?code=BRW&program=ccgg&type=ts

• Argo Float
https://fleetmonitoring.euro-argo.eu

• Remnants of Typhoon Merbok forecast to enter the Arctic Ocean through the Bering Strait from September 17 to 19, 2022.
Discussed at https://www.facebook.com/SamCarana/posts/10166948876390161, from:
https://arctic-news.blogspot.com/p/cold-freshwater-lid-on-north-atlantic.html

• 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

• Sea surface temperature at record high
https://arctic-news.blogspot.com/2023/03/sea-surface-temperature-at-record-high.html

• Record high North Atlantic sea surface temperature



Friday, June 16, 2023

Arctic sea ice under threat - update 2

The NASA Worldview satellite image below shows Arctic sea ice in a poor condition on June 16, 2023, all the way up to the North Pole (on the bottom left of the image below). There is open water near the Franz Josef Archipelago, some 1000 km from the North Pole (on the right side of the image below). Clouds prevent a clearer view of the sea ice.


The Uni of Bremen image below shows Arctic sea ice thickness on June 15, 2023.

The danger is that, as El Niño strengthens, there will be massive loss of Arctic sea ice over the coming months, with water in the Arctic Ocean heating up strongly due to loss of the latent heat buffer and loss of albedo, while huge amounts of ocean heat keep entering the Arctic Ocean from the Atlantic Ocean and the Pacific Ocean.

Furthermore, the Jet Stream is strongly deformed, threatening to result in heatwaves that extend over the Arctic Ocean and that cause hot water from rivers to enter the Arctic Ocean, while storms accelerate the flow of ocean heat into the Arctic Ocean, and while fires and storms contribute to darkening of the sea ice, speeding up its demise.

All this threatens to trigger eruption of methane from the seafloor of the Arctic Ocean, as has been described many times before, such as in this post, in this post and in this post.

[ Latent heat loss, feedback #14 on the Feedbacks page ]
[ see the Extinction page ]
Loss of Arctic sea ice albedo, loss of the latent heat buffer and eruption of seafloor methane all constitute tipping points that threaten to abruptly accelerate the temperature rise in the Arctic, further speeding up loss of permafrost in Siberia and North America and thus threatening to trigger further releases of greenhouse gases.

In addition, there are further events and developments that could unfold and make things even worse.

The upcoming temperature rise on land on the Northern Hemisphere could be of such a severity that much traffic, transport and industrial activity will grind to a halt, resulting in a reduction in cooling aerosols that are now masking the full wrath of global heating. Without these cooling aerosols, the temperature is projected to rise strongly, while there could be an additional temperature rise due to an increase in warming aerosols and gases as a result of more biomass and waste burning and forest fires. Furthermore, as traffic slows down, there will be less nitrogen oxide emissions, which could result in less hydroxyl to curtail methane.

The bar on the right depicts the threat, as discussed at the Extinction page.

In conclusion, the situation is dire and calls for support for a Climate Emergency Declaration.


Links

• Arctic sea ice under threat - update 1

• NOAA - The National Centers for Environment Prediction Climate Forecast System Version 2  

• NOAA - Climate Prediction Center - ENSO Diagnostic Discussions
https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.shtml

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

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


Wednesday, August 10, 2022

Arctic sea ice August 2022

Ocean currents keep pushing heat toward the Arctic Ocean

Arctic sea ice is getting very thin, as temperatures keep rising and ocean currents keep pushing heat toward the Arctic, as illustrated by the NOAA image below that shows sea surface temperatures as high as 33°C or 91.4°F on August 13, 2022. 


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 warming of 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 to speed up this ocean current. The image below shows the Jet Stream over the North Atlantic, where the ocean current dives under the sea ice. Sea surface temperature anomalies are much lower over the area where the deformed Jet Stream causes water to evaporate, thus cooling the surface. 


The danger is that a cold freshwater lid grows at the surface of the North Atlantic that enables large amounts of salty, warm water to dive under the sea ice and enter the Arctic Ocean, as discussed earlier here, as well as here and at the feedbacks page


Latent heat

Latent heat is ocean heat that is, or rather was previously consumed by melting of the sea ice underneath the sea surface. 

[ The Latent Heat Buffer ]
This ice has meanwhile all but disappeared, so without this latent heat buffer further incoming heat must go elsewhere, i.e. the heat will further raise the temperature of the water and it will also cause more evaporation to take place where the sea ice has disappeared altogether, and this in turn will further heat up the atmosphere over the Arctic. 

The nullschool.net image below shows sea surface temperature anomalies from 1981-2011. At the green circle, anomalies were 16.1°C or 29°F on August 9, 2022. Back in 1981-2011, the temperature at that spot was 0°C. 


Thin layer of sea ice

The image below, adapted from University of Bremen, shows Arctic sea ice concentration on August 12, 2022, with concentration in a large area close to the North Pole as low as 0%.


The image below, from NSIDC, also shows sea ice concentration on August 9, 2022. 


The Naval Research Laboratory image below, a forecast for August 18, 2022, run on August 10, 2022, shows that the sea ice is getting very thin. 

Danger of methane eruptions

The navy.mil combination image below has three panels. The left panel shows the sea ice on August 30, 2012, the center panel shows the sea ice on August 30, 2015, and the right panel shows a forecast for the sea ice for August 21, 2022. 

[ click on images to enlarge ]
[ click on images to enlarge ]
There still is a relatively extensive but very thin layer of sea ice present at the surface. This is also illustrated by the NSIDC image on the right that shows an Arctic sea ice extent of 6.438 million km² on August 11, 2022. This relatively large extent is mainly due to the suppression of air temperatures that comes with the current La Niña (see images further below). 

As long as air temperatures are low enough to keep this surface ice frozen and as long as there are no strong winds pushing the ice out of the Arctic Ocean, this thin layer of ice will act as a seal, preventing transfer of heat from the Arctic Ocean to the atmosphere. 


The larger the remaining sea ice is in extent, the less ocean heat can be transferred from the Arctic Ocean to the atmosphere, which means that more heat will remain in the Arctic Ocean.

[ The Buffer has gone, feedback #14 on the Feedbacks page ]
The danger is that ocean heat keeps arriving in the Arctic Ocean, while the latent heat buffer is gone, causing more of this heat to reach sediments at the seafloor of the Arctic Ocean that threatens to destabilize hydrates in these sediment, resulting in methane eruptions both from these hydrates and from free gas underneath these hydrates.

Record high methane levels 

Methane levels are already at record high and growth is accelerating, even without an extra burst of seafloor methane.

NOAA registered a globally averaged marine surface April 2022 mean of 1909.9 ppb, which is 18.7 ppb higher than April 2021, as illustrated by the image on the right. By comparison, the highest annual growth on the NOAA record is 18.31 ppb for 2021. 

NOAA's data are for marine surface measurements.  More methane tends to accumulate at higher altitudes, as illustrated by the image on the right.

The MetOp satellite recorded a mean global methane level of 1971 ppb at 293 mb on August 11, 2022 am. When using a 1-year GWP of 200, this translates into 394.2 ppm CO₂e.

As the image underneath also shows, the MetOp satellite also recorded a peak methane level of 3009 ppb at 469 mb on August 9, 2022 pm. 

Record high carbon dioxide levels

Carbon dioxide (CO₂) levels have been quite high over the past few months. Monthly CO₂ was 420.99 ppm both in May and in June 2022. Some hourly CO₂ measurements were well above 422 ppm in May 2022. On May 28, 2022, one hourly average at Mauna Loa was recorded of 424 ppm.

When adding this monthly CO₂ concentration of 420.99 ppm to the above 394.2 ppm CO₂e for methane, that gives a total of 815.19 ppm CO₂e. 



Clouds feedback

Copernicus recorded high concentrations of methane over the Arctic Ocean on August 16, 2022 (forecast for 03 UTC run on 00 UTC). 

The image below shows methane at surface level, where the scale goes up to 10,000 ppb. At a 1-year global warming potential of 200, this top end of the scale translates into 2000 ppm CO₂e. 

[ click on images to enlarge ]
This 2000 ppm CO₂e is well above the 1200 ppm CO₂e clouds tipping point that will trigger the disappearance of the lower clouds. The presence of lower clouds and sea ice causes a lot of sunlight to be reflected back into space, so the danger is that at locations where these clouds and sea ice cover have both disappeared, the water of the Arctic Ocean will strongly heat up at this time of year.

What makes the situation in the Arctic very dangerous is that there is very little hydroxyl in the air over the Arctic to break down methane.

Furthermore, the Arctic Ocean in many places is very shallow, especially off the coast of Siberia, as illustrated by the NOAA image on the right. Shallow waters enable hot surface water to be mixed down all the way to the seafloor. 

[ click on images to enlarge ]
This threatens to trigger destabilization of methane hydrates contained in sediments at the seafloor and result in eruption of huge amounts of methane from such hydrates as well as from free gas contained in sediments underneath the hydrates, as illustrated by the image on the right, from this page.

Abrupt eruption of an additional 5 Gt of methane from the seafloor of the Arctic Ocean would double the methane in the atmosphere.  

An amount of 5 Gt of methane is only 10% of the 50 Gt that Natalia Shakhova et al. warned about long ago, while 50 Gt is in turn only a small fraction of all the methane contained in sediments in the Arctic, as illustrated by the image on the right, from Shakhova et al. (2019). 

On its own, a 5 Gt eruption of seafloor methane could raise the global mean methane concentration by as much as 1971 ppb which, at a 1-year GWP of 200, would translate into another 394.2 ppm CO₂e and when added to the above 815.19 ppm CO₂e, adds up to a total of 1209.39 ppm CO₂e.

[ from earlier post, click on images to enlarge ]
So, that would abruptly cause the joint CO₂e of just two greenhouse gases, i.e. methane and CO₂, to cross the 1200 ppm clouds tipping point globally and trigger a further 8°C global temperature rise, due to the clouds feedback alone.

There are further forcers and feedbacks to be taken into account, which means that the clouds tipping point could be crossed globally even with a far smaller abrupt release of seafloor methane. While it would take longer for the clouds tipping points to get crossed that way, the associated temperature rise could be enough to drive humans into extinctions well before the tipping point was even reached. A rise of 3°C above pre-industrial could occur on land and drive humans into extinction by 2025.

La Niña

[ adapted from NOAA - click on images to enlarge ]
As said, sea ice extent is relatively large at the moment, because we are currently in the depths of a persistent La Niña, which is suppressing 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 even more dramatic sea ice loss in the Arctic, resulting in runaway temperature rise.

Conclusion

In conclusion, there is a growing risk that methane will erupt from the seafloor of the Arctic Ocean and cause a dramatic rise in temperature. 

Even without such eruption of methane from the seafloor of the Arctic Ocean, temperatures look set to rise strongly soon, as we move into an El Niño and face a peak in sunspots. The resulting temperature rise could drive humans extinct as early as in 2025 with temperatures continuing 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.


Arctic sea ice (previous months)

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

• Arctic sea ice July 2022


Further links

• NOAA - Sea Surface Temperature (SST) Contour Charts
• Jet Stream
https://arctic-news.blogspot.com/p/jet-stream.html

• Cold freshwater lid on North Atlantic
https://arctic-news.blogspot.com/p/cold-freshwater-lid-on-north-atlantic.html

• 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
https://www.ncei.noaa.gov/access/monitoring/monthly-report/global/202207/supplemental/page-4

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

• NSIDC - Arctic sea ice concentration

• NSIDC - Chartic, interactive sea ice graph

• NOAA - Trends in Atmospheric Methane

• nullschool
https://earth.nullschool.net

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

• Understanding the Permafrost–Hydrate System and Associated Methane Releases in the East Siberian Arctic Shelf - by Natalia Shakhova et al. (2019) 
https://www.mdpi.com/2076-3263/9/6/251

• Warning of mass extinction of species, including humans, within one decade
• Cold freshwater lid on North Atlantic

• Albedo, latent heat, insolation and more
https://arctic-news.blogspot.com/p/albedo.html

• Latent Heat Buffer
https://arctic-news.blogspot.com/p/latent-heat.html

• Feedbacks in the Arctic
https://arctic-news.blogspot.com/p/feedbacks.html

• Clouds feedback
https://arctic-news.blogspot.com/p/clouds-feedback.html

• How much time is there left to act?