Wednesday, August 9, 2023

Arctic sea ice August 2023

Arctic Ocean heating up

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

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

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

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

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

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

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

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

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

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


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

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


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


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

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

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

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

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

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

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


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

[ from earlier post ]

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

[ from earlier post ]

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

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

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


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

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

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

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

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

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

Feedbacks and further developments

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

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


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


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

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

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


Links

• Climate Reanalyzer - Outlook Forecast Maps

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

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

• Feedbacks

• Climate Reanalyzer - Daily 2-meter Air Temperature

• NOAA - Sea Surface Temperature (SST) Contour Charts

• NOAA - Global Monitoring Laboratory - Barrow, Alaska

• Feedbacks in the Arctic

• Record high North Atlantic sea surface temperature

• NASA Worldview

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

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

• Cold freshwater lid on North Atlantic





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Sunday, August 6, 2023

Betrayal: The threat to life on Earth

by Andrew Glikson

It has been overlooked during Garma festival that, under current policies, global warming would render aboriginal lands in central and northern Australia unliveable and the top-end a nuclear target…

In his classic book The Fate of the Earth speaking for humanity Jonathan Schell describes the horror of a full-scale nuclear holocaust where human beings and animals would die if twenty thousand megatons of bombs, more than a million times the Hiroshima bomb, explode.

The consequences of a global nuclear exchange belong to the unthinkable. Nuclear weapons are the most destructive, inhumane and indiscriminate weapons ever created. Both on the scale of the devastation they cause and uniquely persistent genetically damaging radioactive fallout, they are unlike any other weapons. A single nuclear bomb detonated over a large city could kill millions of people. The use of tens or hundreds of nuclear bombs would disrupt the atmosphere world-wide, causing widespread famine.

[ Figure 1. Extreme geophysical, meteorological, hydrological and climatological events during 1980 -2012 ]

From the 1970s the full implications of climate change were only beginning to be realized, through a growing string of cyclones, fires, droughts and floods increasing in frequency and intensity above the recent historical record (Figure 1). At that time few could forecast the climate trajectory like NASA’s chief climate scientist (Hansen et al., 2012), who stated:

“Burning all the fossil fuels would create a different planet than the one that humanity knows. The paleoclimate record and ongoing climate change make it clear that the climate system would be pushed beyond tipping points, setting in motion irreversible changes, including ice sheet disintegration with a continually adjusting shoreline, extermination of a substantial fraction of species on the planet, and increasingly devastating regional climate extremes” and “warming according to the IPCC Business As Usual’ (BAU) scenario would lead to a disastrous multi-meter sea level rise on the century timescale” and “We’ve reached a point where we have a crisis, an emergency, but people don’t know that” ...

[ Figure 2. credit: NOAA, click on images to enlarge ]

According to Hans Joachim Schellnhuber, Germany’s chief climate scientist “Climate change is now reaching the end-game, where very soon humanity must choose between taking unprecedented action or accepting that it has been left too late and bear the consequences” …

[ Figure 3. The five mass extinctions in the Earth’s history. ]

Within a century or less the Earth’s mean temperature has risen from the mean levels of the Holocene (the last 11,700 years) and the Pleistocene (11,700 years ago to 2.58 million years ago), to levels of the Pliocene (2.58 million years ago to 5.333 million years ago) to the Miocene (5.33 to 23.03 million years ago), 3 - 4°C warmer than the Holocene, at warming rates. This is faster than any identified in the Cenozoic (66 million years until the present) geological record (Glikson, 2022-23). It is difficult to find in the geological record an event increasing the global greenhouse level at a rate as extreme as the current global heating (Figure 4).

[ Figure 4. Past mean temperatures (200 AD to 2000 AD), current warming and future temperature projections (Steffen, 2012) ]

A nuclear war would represent the ultimate outcome of tribalism, nationalism, racism and war, the human propensity for mutual and self-destruction. There was a time when kings and generals would fall on their sword when they were defeated, or when their faith in their gods collapsed. Nowadays oblivious or non-caring world powers continue to proliferate nuclear weapons on hair trigger alert, mine coal and pump oil and gas, starting a greenhouse chain reaction. Leaders, so-called, opportunistically betray the defence of their own people and the future of their children. The voices of anti-nuclear and climate scientists have become subdued, ignored or betrayed. There may not be too many historians to document the 20-21ˢᵗ centuries crimes against humanity and against nature.

An explanation of the collapse of human society, dragging multiple species down with it, arises from Fermi’s Paradox, where the combination of technological achievements and an inherent killer instinct of some leads to collapse.


Andrew Glikson
A/Prof. Andrew Y Glikson
Earth and Paleo-climate scientist

Books:
The Asteroid Impact Connection of Planetary Evolution
https://www.springer.com/gp/book/9789400763272
The Archaean: Geological and Geochemical Windows into the Early Earth
https://www.springer.com/gp/book/9783319079073
The Plutocene: Blueprints for a Post-Anthropocene Greenhouse Earth
https://www.springer.com/gp/book/9783319572369
The Event Horizon: Homo Prometheus and the Climate Catastrophe
https://www.springer.com/gp/book/9783030547332
Climate, Fire and Human Evolution: The Deep Time Dimensions of the Anthropocene
https://www.springer.com/gp/book/9783319225111
Evolution of the Atmosphere, Fire and the Anthropocene Climate Event Horizon
https://www.springer.com/gp/book/9789400773318
From Stars to Brains: Milestones in the Planetary Evolution of Life and Intelligence
https://www.springer.com/us/book/9783030106027
Asteroids Impacts, Crustal Evolution and Related Mineral Systems with Special Reference to Australia
https://www.springer.com/us/book/9783319745442
The Fatal Species: From Warlike Primates to Planetary Mass Extinction
https://www.springer.com/gp/book/9783030754679
The Trials of Gaia. Milestones in the evolution of Earth with reference to the Antropocene
https://www.amazon.com.au/Trials-Gaia-Milestones-Evolution-Anthropocene/dp/3031237080


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Monday, July 31, 2023

Wet Bulb Globe Temperature Tipping Point

High Wet Bulb Globe Temperatures (WBGT) are forecast to hit Louisiana, United States, over the next few days. The image below shows a forecast for August 2, 2023, 18 UTC, with WBGT as high as 35°C forecast for a location 10 miles South East of Abbeville, Louisiana, U.S.


WBGT is a measure used by weather.gov to warn about expected heat stress when in direct sunlight. It takes into account the effect of temperature, relative humidity, wind speed, and solar radiation on humans.

As temperatures and humidity levels keep rising, a tipping point can be reached where the wind factor no longer matters, in the sense that wind can no longer provide cooling. The human body can cool itself by sweating, which has a physiological limit that was long described as a 35°C wet-bulb temperature. Once the wet-bulb temperature reaches 35°C, one can no longer lose heat by perspiration, even in strong wind, but instead one will start gaining heat from the air beyond a wet-bulb temperature of 35°C.

Accordingly, a 35°C wet-bulb temperature (equal to 95°F at 100% humidity or 115°F at 50% humidity) was long seen as the theoretical limit, the maximum a human could endure.

A 2020 study (by Raymond et al.) warns that this limit could be regularly exceeded with a temperature rise of less than 2.5°C (compared to pre-industrial). A 2018 study (by Strona & Bradshaw) indicates that most life on Earth will disappear with a 5°C rise. Humans, who depend for their survival on many other species, will likely go extinct with a 3°C rise, as illustrated by the image below, from an earlier post.


A 2022 study (by Vecellio et al.) finds that the actual limit is lower — about 31°C wet-bulb or 87°F at 100% humidity — even for young, healthy subjects. The temperature for older populations, who are more vulnerable to heat, is likely even lower. In practice the limit will typically be lower and depending on circumstances could be as low as a wet-bulb temperature of 25°C.


The above image shows a Wet Bulb Globe Temperature of 35°C (95°F) forecast for August 11, 2023, 19 UTC, for a location near Baton Rouge, Louisiana, U.S. 


Heat is the leading cause of weather-related deaths in the United States, as illustrated by the above image (credit: NOAA). Heat fatalities may be conservative figures. Recent research finds that where heat is being listed as an official cause of death, this likely underestimates the full toll of these events. Extreme heat can trigger heart attacks and strokes. In addition, some heart disease risk factors, such as diabetes—as well as heart medications, such as diuretics and beta blockers—can affect a person’s ability to regulate their body temperature and make it difficult to handle extreme heat. The study finds that extreme heat accounted for about 600-700 additional deaths from cardiovascular disease annually. A recent study estimates that extreme heat accounted for 12,000 premature deaths in the contiguous U.S. from 2000 to 2010, and a recent analysis calculates that the summer 2022 heatwave killed 61,000 people in Europe alone. 

The image below shows a temperature (°F) forecast for August 1, 2023, from Climate Reanalyzer. 


The video below discusses this.


Misery Index

The image below show a high reading on the 'Misery Index', the perceived ('feels like') temperature that is used by nullschool.net, combining wind chill and the heat index (which in turn combines air temperature and relative humidity, in shaded areas). A Misery Index temperature of 56.1°C or 133.1°F was recorded at a location off the coast of the United Arab Emirates (green circle) on August 5, 2023.


The temperature at that location at the time was 35.2°C or 95.4°F, lower than the temperature on the land surrounding the Gulf, but the relative humidity at that spot over the water was 78%, and that combination led to this very high 'feels like' temperature. 

This constitutes a warning. The sea, rivers and lakes are traditionally seen as places to go to, to cool off. However, high temperatures combined with high humidity over water bodies can result in conditions that go beyond what humans can bear. 

Climate change danger assessment

The image below, earlier discussed here, expands risk assessment beyond its typical definition as the product of the severity of impact and probability of occurrence, by adding a third dimension: timescale, in particular imminence.




Imminence alone could make that the danger constituted by rising temperatures needs to be acted upon immediately, comprehensively and effectively. While questions may remain regarding probability, severity and timescale of the dangers associated with climate change, the precautionary principle should prevail and this should prompt for action, i.e. comprehensive and effective action to reduce damage and improve the situation is imperative and must be taken as soon as possible.

Rapidly rising temperatures constitute tipping points in several ways 

Firstly, there is a biological threshold beyond which rising temperatures become lethal for humans, as discussed above. 

Secondly, as Gerardo Ceballos describes in the video below and in a 2017 analysis, there is a biological tipping point that threatens annihilation of species via the ongoing sixth mass extinction. Researchers such as Gerardo Ceballos (2020), Kevin Burke (2018) and Ignation Quintero (2013) have for years warned that mammals and vertebrates cannot keep up with the rapid rise in temperature. Humans are classified as vertebrate mammals, indicating that we will not avoid the fate of extinction, Guy McPherson (2020) adds. 

Thirdly, there are further tipping points, e.g. social-political ones. On the one hand, it would be good if people became more aware, as this could prompt more people into supporting the necessary action. On the other hand, as temperatures keep rising, there is also a danger that panic will break out, dictators will grab power and civilization as we know it will collapse abruptly, as warned about earlier, e.g. in 2007.  



Conclusion

In conclusion, to combat rising temperatures, transforming society is needed urgently, along the lines of this 2022 post in combination with declaration of a climate emergency.


Links

• Wet Bulb Globe Temperature
https://digital.mdl.nws.noaa.gov

• National Weather Service - Wet Bulb Globe Temperature: How and when to use it
https://www.weather.gov/news/211009-WBGT

• The emergence of heat and humidity too severe for human tolerance - by Colin Raymons et al. (2020)
https://www.science.org/doi/10.1126/sciadv.aaw1838

• Brief periods of dangerous humid heat arrive decades early
https://www.climate.gov/news-features/featured-images/brief-periods-dangerous-humid-heat-arrive-decades-early

• Evaluating the 35°C wet-bulb temperature adaptability threshold for young, healthy subjects (PSU HEAT Project) - by Daniel Vecellio et al. (2022)
https://journals.physiology.org/doi/full/10.1152/japplphysiol.00738.2021
Discussed at: https://www.facebook.com/groups/arcticnews/posts/10159973158374679

• NOAA - Weather Fatalities 2022
https://www.weather.gov/hazstat

• The Effects of Heat Exposure on Human Mortality Throughout the United States - by Drew Shindell (2021)
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019GH000234

• Heat-related mortality in Europe during the summer of 2022 - by Joan Ballester et al.
https://www.nature.com/articles/s41591-023-02419-z
Discussed at: https://www.facebook.com/groups/arcticnews/posts/10160875637104679

• As Temperatures Spike, So Do Deaths from Heart Disease (2022 News release)
https://www.acc.org/About-ACC/Press-Releases/2022/03/22/20/06/As-Temperatures-Spike-So-Do-Deaths-from-Heart-Disease

• Association of Extreme Heat and Cardiovascular Mortality in the United States: A County-Level Longitudinal Analysis From 2008 to 2017 - by Sameed Khatana et al. (2022)
https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.122.060746

• Co-extinctions annihilate planetary life during extreme environmental change, by Giovanni Strona and Corey Bradshaw (2018)
https://www.nature.com/articles/s41598-018-35068-1
Discussed at: https://www.facebook.com/groups/arcticnews/posts/10156903792219679

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

• Climate Reanalyzer - Hourly Forecast Maps
https://climatereanalyzer.org/wx/fcst/?mdl_id=nam&dm_id=conus-lc&wm_id=t2

• PBS video - Too HOT and HUMID to Live: Extreme Wet Bulb Events are on the Rise 
https://www.pbs.org/video/too-hot-and-humid-to-live-extreme-wet-bulb-events-are-on-th-fazocs

• Nullschool
https://earth.nullschool.net

• How agriculture hastens species extinction | 60 Minutes (CBS News) | Gerardo Ceballos
https://www.youtube.com/watch?app=desktop&v=f21WWocqR-c

• Biological annihilation via the ongoing sixth mass extinction signaled by vertebrate population losses and declines - by Gerardo Ceballos, Paul R. Ehrlich and Rodolfo Dirzo (2017)
https://www.pnas.org/content/114/30/E6089

• Vertebrates on the brink as indicators of biological annihilation and the sixth mass extinction - by Gerardo Ceballos, Paul Ehrlich, and Peter Raven (2020)
https://www.pnas.org/content/early/2020/05/27/1922686117
Discussed at: https://www.facebook.com/groups/arcticnews/posts/10158460232764679

• Rates of projected climate change dramatically exceed past rates of climatic niche evolution among vertebrate species - by Ignatio Quintero et al. (2013) 

• Pliocene and Eocene provide best analogs for near-future climates - by Kevin Burke et al. (2018)
https://www.pnas.org/doi/10.1073/pnas.1809600115
Discussed at: https://www.facebook.com/groups/arcticnews/posts/10156972951354679

• Earth is in the Midst of Abrupt, Irreversible Climate Change - by Guy McPherson (2020)
https://www.onlinescientificresearch.com/articles/earth-is-in-the-midst-of-abrupt-irreversible-climate-change.pdf
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Thursday, July 27, 2023

Record high North Atlantic sea surface temperature

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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


Arctic reaches record high air temperature

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


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

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

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

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

Latent heat loss, feedback #14 on the Feedbacks page

Feedbacks

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

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

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

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

Conclusion

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


Links

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

• Nullschool
https://earth.nullschool.net

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

• Copernicus
https://climate.copernicus.eu

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

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

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

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


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

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

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

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





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