Showing posts with label hydrates. Show all posts
Showing posts with label hydrates. Show all posts

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


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



Thursday, December 15, 2022

Antarctic sea ice in rapid decline


Earlier this year, on February 25, Antarctic sea ice extent was at an all-time record low of 1.924 million km², as the above image shows. Throughout the year, Antarctic sea ice extent has been low. On December 14, 2022, Antarctic sea ice was merely 9.864 million km² in extent. Only in 2016 was Antarctic sea ice extent lower at that time of year, and - importantly - 2016 was a strong El Niño year.

The NOAA image on the right indicates that, while we're still in the depths of a persistent La Niña, the next El Niño looks set to strike soon.

Meanwhile, ocean heat content keeps rising due to high levels of greenhouse gases, as illustrated by the image on the right. 

Rising ocean heat causes sea ice to melt from below, resulting in less sea ice, which in turn means that less sunlight gets reflected back into space and more sunlight gets absorbed as heat in the ocean, making it a self-reinforcing feedback loop that further speeds up sea ice loss. 

The currently very rapid decline in sea ice concentration around Antarctica is illustrated by the animation of Climate Reanalyzer images on the right, showing Antarctic sea ice on November 16, November 29 and December 15, 2022.

In 2012, a research team led by Jemma Wadham studied Antarctica, concluding that an amount of 21,000 Gt or billion tonnes or petagram (1Pg equals 10¹⁵g) of organic carbon is buried beneath the Antarctic Ice Sheet, as discussed in an earlier post

The potential amount of methane hydrate and free methane gas beneath the Antarctic Ice Sheet could be up to 400 billion tonnes. 

The predicted shallow depth of these potential reserves also makes them more susceptible to climate forcing than other methane hydrate reserves on Earth, describes the news release

“We are sleepwalking into a catastrophe for humanity. We need to take notice right now. It is already happening. This is not a wait-and-see situation anymore," Jemma Wadham said more recently.

The animation on the right shows the thickness of Antarctic sea ice up to December 14, 2022, with 8 days of forecasts added.  

On December 29, 2022, Antarctic sea ice extent was at a record low for the time of the year, at 5.527 million km² (see image on the right). 

Recently, a study discovered a process that can contribute to the melting of ice shelves in the Antarctic, as discussed at the ArcticNews group

Ominously, high concentrations of methane have been recorded over Antarctica recently. The image below shows methane as recorded by the Metop-B satellite on November 28, 2022 pm at 399 mb. 

Global sea ice extent was also at a record low for the time of year on December 29, 2022, at 17.53 million km², as illustrated by the image below, by the National Institute of Polar Research, Japan


The situation is dire and the right thing to do now is to help avoid or delay the worst from happening, through action as described in the Climate Plan.


Links

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

• 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 - ocean heat content
https://www.ncei.noaa.gov/access/global-ocean-heat-content/index.html

• Climate Reanalyzer sea ice concentration
https://climatereanalyzer.org/wx/todays-weather/?var_id=seaice-snowc&ortho=7&wt=1

• Naval Research Laboratory - Antarctic sea ice 
https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/antarc.html

• Potential methane reservoirs beneath Antarctica - Press release University of Bristol (2012)
https://www.bristol.ac.uk/news/2012/8742.html

• Potential methane reservoirs beneath Antarctica - by Jemma Wadham et al. (2012)
https://www.nature.com/articles/nature11374

• A new frontier in climate change science: connections between ice sheets, carbon and food webs

• Ocean variability beneath Thwaites Eastern Ice Shelf driven by the Pine Island Bay Gyre strength - by Tiago Dotto et al.
https://www.nature.com/articles/s41467-022-35499-5

• Metop-B satellite readings

• National Institute of Polar Research, Japan
• Climate Plan
https://arctic-news.blogspot.com/p/climateplan.html



Monday, August 22, 2022

Dangerously large Arctic sea ice extent

Arctic sea ice extent was 5.88 million km² on August 21, 2022, larger in extent than in any of the years from 2010 through 2021 at this time of year, as illustrated by the NSIDC image below. 


At first glance, one might think that this relatively large extent was a sign of healthy sea ice. After all, the larger the sea ice, the more sunlight gets reflected back into space. At the same time, however, the situation is very dangerous, as there is a growing risk that large eruptions of methane will occur from the seafloor of the Arctic Ocean.

Why is the situation so dangerous? There are many contributors to the danger, three of them are:

1. Ice acts as a seal

Ice acts as a seal, insulating the soil from warmer air and holding the soil together, like a glue. A 2022 study by Elizabeth Webb et al. concludes that rainwater carries heat into the soil and accelerates permafrost thaw, and the glue that holds the soil together disappears. This can open up underground channels that drain the surface. 

Rainwater can also travel along cracks deeper into sediments, where the heat can destabilize methane hydrates, resulting in the release of large amounts of methane into the atmosphere from hydrates and from gas underneath hydrates. As temperatures rise in the Arctic, more rain will fall over the Arctic, increasing this danger.


Where rain falls onto the sea ice, the rainwater also adds heat to the sea ice, speeding up its demise, and stronger winds can further accelerate this. The compound impact is that such feedbacks accelerate the pace at which the Arctic is warming, but as long as air temperatures are low enough, there will continue to be sea ice that acts as a seal, impeding transfer of ocean heat from the Arctic Ocean to the atmosphere. 

Temperatures in the Arctic are rising faster than in the rest of the world. As temperatures rise in the Arctic, increased precipitation, meltwater and runoff from land, and flow of freshwater from rivers all decrease salinity of the water in the Arctic Ocean. Lower salinity makes it harder for sea ice to melt. 

As temperatures in the Arctic are rising faster than in the rest of the world, the Jet stream is getting deformed. Deformation of the Jet Stream causes more wind to go over the Arctic Ocean, which can cool down the sea surface, resulting in more extensive sea ice. 

Furthermore, we're currently in the depth of a persistent La Niña (NOAA image on the right), and the associated lower air temperatures further contribute to a relatively larger extent of the sea ice. 

More extensive sea ice in turn makes it harder for ocean heat to be transferred to the atmosphere, thus instead raising the temperature of the water of the Arctic Ocean.


The larger the 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.

2. Lid on North Atlantic

Ocean stratification is increasing globally, as ocean warming is stronger for upper layers versus the deep ocean. Stratification increased from 1960 to 2018 by 5.3% for the upper 2000m and by as much as 18% for the upper 150m, while salinity changes also play an important role locally, a 2020 study finds.

[ SSTA (left) and SST (right), August 23, 2022 - click on image to enlarge ]

Deformation of the Jet Stream can at times strongly increase evaporation over the North Atlantic with more precipitation further down the path of the Atlantic meridional overturning circulation (AMOC).

Deformation of the Jet Stream can also increase runoff from land (including from melting glaciers).

In both these cases, this can contribute to the formation and growth of a relatively cold, freshwater lid at the surface of the North Atlantic.


This lid on the North Atlantic reduces transfer of ocean heat to the atmosphere and enables large amounts of salty, warm water to enter the Arctic Ocean, diving under the sea ice. 

This lid also increases the risk of a sudden, large influx of hot, salty water. Slowdown of AMOC causes ocean heat to accumulate, while more warm water travels underneath this lid (instead of at the sea surface) toward the Arctic Ocean. As the Jet Stream gets more deformed, strong winds along the path of AMOC can at times speed up the flow of water that travels underneath this cold freshwater lid over the North Atlantic, suddenly pushing large amounts of salty, warm water into the Arctic Ocean. 

3. Latent heat buffer loss

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 30, 2022, run on August 22, 2022.


The image illustrates that Arctic sea ice is currently larger in extent than it was in 2012 and 2015 at this time of year, while there has been a dramatic reduction in thickness of the sea ice over time.

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.


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 of the Arctic Ocean.

Compound impact

The danger is that, as more salty, warm water keeps arriving in the Arctic Ocean while the latent heat buffer has largely disappeared and while sea ice extent is relatively large, this will raise the temperatures and salinity levels at the bottom of the Arctic Ocean enough to destabilize hydrates in sediment at the seafloor of the Arctic Ocean, resulting in methane eruptions both from these hydrates and from free gas underneath these hydrates.

[ The Buffer has gone, feedback #14 on the Feedbacks page ]
Very high methane levels

The Copernicus image below shows a forecast of high levels of methane over the Arctic on August 28, 2022 18:00 UTC at 500 hPa. 


Methane levels are already at record high and growth is accelerating, even without an extra burst of seafloor methane. The NOAA record shows that methane grew by 18.31 ppb in 2021, the highest annual growth on record. 

The most recent monthly NOAA data are for the globally averaged marine surface mean for April 2022, which was 1909.9 ppb. This is 18.7 ppb higher than April 2021, as illustrated by the image on the right, from an earlier post.

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

The top data image on the right shows methane recorded by the MetOp satellite on August 22, 2022 am. The image shows means of 1972 ppb at five pressure levels (of 280 mb and less), with a peak level of 2543 ppb, the highest that day, occurring at 218 mb.

The second data image on the right shows methane means recorded by the MetOp satellite on August 25, 2022 pm of 1975 ppb at four pressure levels (at 254 mb, 266 mb, 280 mb and 283 mb).

The image underneath on the right shows a methane peak of 2622 ppb (marked by the red oval), recorded by the N20 satellite on August 20, 2022 am at 399.1 mb. High methane levels are visible north of Siberia, indicating that much of the methane may originate in the Arctic.

Another N20 satellite image is added underneath showing high methane concentrations over the Arctic, also on August 20, 2022 am, but at 695.1 mb, which is much closer to sea level. This confirms that much of the methane may have originated in the Arctic.

An image is added underneath from another satellite, the MetOp satellite, also showing high methane concentrations over the Arctic, also on August 20, 2022 am, this time at 586 mb, further confirming that much of the methane may have originated in the Arctic.

A large abrupt methane release could double the methane in the atmosphere. Methane releases from the seafloor of the Arctic Ocean are very dangerous because there is very little hydroxyl in the atmosphere over the Arctic to break down the methane.
A level twice as high as that 1975 ppb mean is a mean of 3950 ppb, and when using a 1-year GWP of 200, this translates into 790 ppm CO₂e, i.e. only 410 ppm away from the 1200 ppm clouds tipping point.

The average monthly CO₂ at Mauna Loa, Hawaii, was 420.99 ppm both in May and in June 2022. As illustrated by the image on the right, average daily CO₂ hasn't been below 416 ppm in July and August 2022, while some hourly measurements were around 425 ppm CO₂.
On August 25, 2022 16:30 UTC, CO₂ at the North Pole was 422 ppm, as illustrated by the nullschool.net image on the right. 

In other words, a large eruption of methane from the seafloor of the Arctic Ocean could 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. When adding further forcers, a huge temperature rise could be triggered even with far less methane erupting from the seafloor.

Conclusion

In conclusion, there is a growing danger 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. 

Either way, the resulting temperature rise could drive humans extinct as early as in 2025 with temperatures continuing to skyrocket in 2026

This makes 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 (earlier posts in 2022)

• Arctic sea ice June 2022 - why the situation is so dangerous
https://arctic-news.blogspot.com/2022/06/arctic-sea-ice-june-2022-why-situation-is-so-dangerous.html

• Arctic sea ice July 2022
https://arctic-news.blogspot.com/2022/07/arctic-sea-ice-july-2022.html

• Arctic sea ice August 2022


Further links

• Permafrost thaw drives surface water decline across lake-rich regions of the Arctic - by Elizabeth Webb et al. 
also discussed at: 

• Increasing ocean stratification over the past half-century - by Guancheng Li et al. 
https://www.nature.com/articles/s41558-020-00918-2

• The ocean has become more stratified with global warming - news release

• IPCC AR6 WG1 SPM


• NOAA - Globally averaged marine surface annual mean methane growth rates.

• NOAA - Trends in Atmospheric Carbon Dioxide

• NOAA - MetOp satellite 

• NOAA - N20 satellite

• 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 - 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
https://nsidc.org/arcticseaicenews

• NSIDC - Chartic, interactive sea ice graph
https://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph

• NOAA - Trends in Atmospheric Methane
https://gml.noaa.gov/ccgg/trends_ch4

• 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
https://arctic-news.blogspot.com/2017/02/warning-of-mass-extinction-of-species-including-humans-within-one-decade.html

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

• 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?
https://arctic-news.blogspot.com/p/how-much-time-is-there-left-to-act.html

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

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

• Human Extinction by 2025?
https://arctic-news.blogspot.com/2022/07/human-extinction-by-2025.html

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

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



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?