Showing posts with label thickness. Show all posts
Showing posts with label thickness. Show all posts

Friday, January 19, 2024

Potential temperature trends

[ click on images to enlarge ]

The above image shows potential temperature trends. Four of the trends are global ones and one trend is based on Arctic (64°North-90°North) data:

  • The red line is a polynomial trend based on 15 years of Arctic data (2009-2023).
  • The green line is a linear trend based on 1880-2023 global data.
  • The yellow line is a linear trend based on 2009-2023 global data.
  • The light blue line is a 10-year moving average (trailing), based on global data.
  • The dark blue line is a polynomial trend, based on 2015-2023 global data, showing global temperatures catching up with the Arctic rise in temperature.

Note that the above image uses annual anomalies from 1951-1980. Recent posts show that, when adjustments are made for an earlier base, for ocean air temperatures and for higher polar anomalies, the 2023 anomaly could be as high as 2.5°C from pre-industrial and when using monthly data, the anomaly could be as high as 2.73°C from pre-industrial. 

Temperature rise hits Arctic most strongly 

Due to feedbacks such as sea ice loss, the temperature rise is felt most strongly at higher latitudes North, as illustrated by the three images below, again using a 1951-1980 baseline.

The image below shows the December 2023 temperature anomaly. 

The image below shows the 2023 temperature anomaly. 

The image below shows how the temperature rise has unfolded from 2000.  

[ Arctic Ocean hit most strongly by temperature rise ]

Over the next few years, the temperature rise in the Arctic could accelerate even more strongly as a result of crossing of two tipping points, i.e. the Latent Heat Tipping Point and the Seafloor Methane Tipping Point, as illustrated by the image below, from an earlier post.

[ increasing ocean heat ]
Note again that annual data are used in the above image. An earlier analysis using monthly data shows that the seafloor methane tipping point was reached in August 2023.

Arctic sea ice extent

Arctic sea ice extent in 2024 was larger than many expected. One of the reasons for this is that Greenland ice has been melting faster than previously thought, as pointed out by a recent study that also includes retreat of glaciers that already lie mostly below sea level. More melting of ice on Greenland has resulted in a larger south-bound flow of icebergs and meltwater, contributing to cooling of the North Atlantic sea surface and slowing down of the Atlantic meridional overturning circulation (AMOC), and in turn contributing to suppress temperatures in the Arctic. As a result, loss of Arctic sea ice extent has been less than would otherwise have been the case. Yet, the temperature rise may soon overwhelm this suppression.

Cold freshwater lid at surface of North Atlantic

[ ocean stratification, from earlier post ]

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 (see above image) as temperatures rise, 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 danger is that huge amounts of ocean heat can abruptly get pushed into the Arctic Ocean and that the influx of ocean heat will 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 ]

This danger is further illustrated by the above compilation image, showing forecasts for January 27, 2024 of:
(1) surface wind and temperature (-3.6°C or 25.4°F at the North Pole)
(2) surface wind
(3) wind at 700 hPa
(4) wind at 250 hPa (Jet Stream) and
(5) ocean currents at surface and wave height.

The image below shows that temperatures are forecast to be above freezing near the North Pole on January 26, 2024 20:00 UTC (downloaded January 26, 2024 06:00 UTC). 


Ominously, the North Atlantic sea surface was much hotter in early 2024 than it was in early 2023.


And ominously, the daily sea surface temperature reached a record high on January 31, 2024, when the daily sea surface temperature reached 21.10°C, higher than the peak of 21.09°C reached in August 2023 and much higher than the 20.99°C peak reached in March 2016.


As latent heat buffer shrinks, Arctic sea ice could melt away quickly

As illustrated by the image below, sea ice was very thin near the North Pole on January 24, 2024, indicating there is very little left of the latent heat buffer constituted by the sea ice to consume incoming heat. 
And even more ominously, Arctic sea ice thickness declined dramatically in a few days time, as indicated by the compilation image below, with images from the University of Bremen. 


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, Arctic sea ice volume now is among the lowest of all years on record for the time of year, as illustrated by the image below. Volume = extent x thickness, so low volume and relatively large extent means that sea ice is very thin. 
As more sunlight starts reaching the Northern Hemisphere, in line with seasonal changes, Arctic sea ice extent can be affected dramatically and abruptly, as illustrated by the image below.

Furthermore, much of the thicker sea ice is located off the east coast of Greenland, as illustrated by the image below. This means that this sea ice is likely to melt away quickly as temperatures rise in line with seasonal changes.
Without the buffer constituted by thicker sea ice, such 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. 
[ The buffer is gone - Latent Heat Tipping Point crossed ]

Given methane's very high immediate global warming potential (GWP), this could push up temperatures dramatically and rapidly. 

[ potential methane rise, from earlier post ]

[ from the Extinction page ]
The above image shows a polynomial trend added to NOAA globally averaged marine surface monthly mean methane data from April 2018 to November 2022, pointing at 1200 ppm CO₂e (carbon dioxide equivalent) getting crossed in 2027.

A rise in methane concentrations alone may suffice to cause the Clouds Tipping Point, at 1200 ppm CO₂e, to get crossed. The resulting clouds feedback could on its own cause the temperature to rise by a further 8°C. 

When further forcing is taken into account, crossing of the Clouds Tipping Point could occur even earlier than in 2027.

The image on the right illustrates how a huge temperature could unfold and reach more than 18°C above pre-industrial by 2026.

With such a rise, the temperature is likely to keep rising further, with further water vapor accumulating in the atmosphere once the water vapor tipping point gets crossed, as discussed in an earlier post and at Could Earth go the same way as Venus? 

As a rather sobering footnote, humans will likely go extinct with a 3°C rise and most life on Earth will disappear with a 5°C rise, as illustrated by the image below, from an earlier post.
[ from earlier post ]

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

• NASA - Goddard Institute for Space Studies (GISS) Surface Temperature Analysis
https://data.giss.nasa.gov/gistemp

• Ubiquitous acceleration in Greenland Ice Sheet calving from 1985 to 2022 - by Char Greene et al. https://www.nature.com/articles/s41586-023-06863-2
discussed at facebook at: 
https://www.facebook.com/groups/arcticnews/posts/10161223121909679

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

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

• Pre-industrial
https://arctic-news.blogspot.com/p/pre-industrial.html

• Could Earth go the same way as Venus?

Monday, July 10, 2023

Arctic sea ice July 2023

World temperatures during each of the past 16 days have been higher than they have been for millions of years. Moreover, the temperature is now rising faster than during any period before, and could rise 18.44°C (versus pre-industrial) by the year 2026.


In each of the past 16 days, the temperature has been higher than the peak temperature reached in previous years in the record going back to 1979, i.e. 16.92°C (62.46°F) reached on July 24, 2022 (orange), as well as on August 13+14, 2016.
July   3, 2023: 17.01°C or 62.62°F
July   4, 2023: 17.18°C or 62.92°F
July   5, 2023: 17.18°C or 62.92°F
July   6, 2023: 17.23°C or 63.01°F
July   7, 2023: 17.20°C or 62.96°F
July   8, 2023: 17.17°C or 62.91°F
July   9, 2023: 17.11°C or 62.80°F
July 10, 2023: 17.12°C or 62.82°F
July 11, 2023: 17.08°C or 62.74°F
July 12, 2023: 17.04°C or 62.67°F
July 13, 2023: 16.98°C or 62.56°F
July 14, 2023: 16.94°C or 62.49°F
July 15, 2023: 16.99°C or 62.58°F
July 16, 2023: 17.03°C or 62.65°F
July 17, 2023: 17.11°C or 62.80°F
July 18, 2023: 17.17°C or 62.91°F
The comparison with the year 2016 is important, since 2016 was a strong El Niño year and the peak temperature in that year was reached in August. Therefore, if indicative, temperatures in 2023 may reach even higher peaks later this month and in August, which seems confirmed by predictions of the currently unfolding El Niño, such as the above image from Copernicus, showing El Niño gaining in strength.

Arctic Ocean heating up

The Arctic reached high temperatures on July 9, 2023, as illustrated by the combination image below, created with nullschool.net images.

[ click on images to enlarge ]
1. Firstly, the water of the Arctic Ocean heats up as it receives direct heat from sunlight. The globe on the right on the above combination image shows that on July 9, 2023, a temperature of 33°C or 91.3°F was recorded in Canada over land near the Arctic Ocean and near the Mackenzie River (green circle), with the heatwave on land extending over the Arctic Ocean. As the globe at the center shows, sea surface temperature anomalies as high as 13.2°C or 23.7°F were recorded that day nearby, in the area marked by the green circle. 

2. Hot water from rivers ending in the Arctic Ocean is another way the water is heating up, as also illustrated by the above image. 

The above globe on the left shows that, on July 9, 2023, sea surface temperatures as high as 13.5°C or 56.4°F were recorded at a location nearby location where the Mackenzie River flows into the Arctic Ocean (at the green circle), while on July 23, 2023, the sea surface was 13.8°C or 24.8°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 on the right, the sea surface was 18.4°C or 33°F hotter than in 1981-2011 where the Ob River meets the Kara Sea (at the green circle) on July 24, 2023.  

The image on the right shows sea surface temperatures in the Bering Strait as high as 18.8°C or 65.4°F on July 27, 2023. The water heats up strongly where hot water from rivers and run-off from rainwater enters the Bering Strait. 

3. Yet another way heat is entering the Arctic Ocean is from oceans, i.e. from the North Atlantic Ocean and the Pacific Ocean, and this is melting the sea ice from below. 

The image below, created with Climate Reanalyzer images, shows that the North Atlantic sea surface temperature was 24.8°C on July 21, 2023 (black), no less than 1.2°C higher than the 23.6°C recorded on July 21, 2022 (orange).


As the above image also shows, a record high temperature was reached on the North Atlantic of 24.9°C on September 4, 2022. 

The comparison with the peak in 2022 is important, as it was reached at a time when La Niña was suppressing the temperature, whereas now El Niño is strongly pushing up the temperature. Therefore, if the 1.2°C difference is indicative, temperatures above 26°C can be expected for the North Atlantic in September this year.

The image on the right shows sea surface temperatures as high as 33.6°C or 92.4°F off the Florida coast (green circle) on July 13, 2023.

A buoy in Manatee Bay in the Upper Keys south of Florida recorded a water temperature of 38.89°C or 101.1°F on July 24, 2023.

The image below shows sea surface temperatures as high as 33°C or 91.4°F on July 27, 2023.


The video below gives a sequential view of the situation:


The Gulf Stream is pushing ocean heat toward the Arctic Ocean, as illustrated by the image below.


It takes some time for peak ocean heat to reach the Arctic Ocean. Arctic sea ice typically reaches an annual minimum extent about mid-September.

As the above image also shows, a sea surface temperature east of Svalbard of 10.6°C or 51°F was recorded on July 15, 2023 (at the green circle).

Arctic sea ice under threat

As described in earlier posts such as this one, this rapid temperature rise threatens to cause Arctic sea ice to disappear.

The three images on the right, adapted from University of Bremen, shows that Arctic sea ice thickness is very vulnerable. 

The top image shows that most Arctic sea ice was less than 20 cm thick on July 16, 2023.

The second image on the right shows Arctic sea ice concentration on July 9, 2023.

The image underneath shows sea ice age for the week of June 25 to July 1, 2023, from NSIDC.

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.

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

Conclusion

The outlook is dire and is getting more dire every day.

This 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


• Nullschool
https://earth.nullschool.net

• Climate Reanalyzer - sea surface temperature

• Potential world record: South Florida ocean temperature surges beyond 100 degrees 

• Copernicus

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

• The Threat
https://arctic-news.blogspot.com/p/threat.html

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

• NSIDC - Mid-summer bliss - sea ice age
https://nsidc.org/arcticseaicenews/2023/07/mid-summer-bliss

• NOAA - Global Monitoring Laboratory - Barrow, Alaska





Friday, June 30, 2023

Arctic sea ice under threat - update 5

The NASA Worldview satellite image below shows Arctic sea ice on June 29, 2023, with the North Pole on the left. 


The animation below shows that, while clouds can obscure a closer look, sea ice is clearly very thin with the thickest ice breaking up near the top of Greenland, some 750 km from the North Pole. 


The Uni of Bremen image below shows Arctic sea ice thickness on June 28, 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.

The image below shows that the North Atlantic sea surface temperature was 23.5°C on June 28, 2023 (on the black line), 0.9°C higher than the 22.6°C on June 28, 2022 (on the orange line). A record high of 24.9°C was reached on Sept. 4, 2022, even while La Niña was suppressing the temperature. This time, there's an El Niño. 


The image below, adapted from NOAA, shows ocean heat moving toward the Arctic along the path of the Gulf Stream on June 25, 2023, while sea surface temperatures on the map are as high as 32.6°C.


In addition, the Jet Stream is strongly deformed, and this threatens to strengthen heatwaves extending over the Arctic Ocean and causing hot water from rivers to enter the Arctic Ocean, and to strengthen storms accelerating the flow of ocean heat into the Arctic Ocean, while fires and storms contribute to darkening of the sea ice, further speeding up its demise.

The danger is that, as El Niño strengthens and as ocean heat keeps entering the Arctic Ocean from the Atlantic Ocean and the Pacific Ocean, a huge amount of heat will abruptly be pushed into the Arctic Ocean.

This danger is illustrated by the image on the right, from an earlier post, showing the Jet Stream pushing wind at a speed of 126 km/h (78 mph) up through Fram Strait (at the green circle) into the Arctic Ocean on June 21, 2023.

This situation threatens to cause 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.

This in turn threatens to trigger methane eruptions from the seafloor of the Arctic Ocean, a threat that has been described many times before, such as here, here and here.

[ 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

• Arctic sea ice under threat - update 1

• Arctic sea ice under threat - update 2

• Arctic sea ice under threat - update 3
https://arctic-news.blogspot.com/2023/06/arctic-sea-ice-under-threat-update-3.html

• Arctic sea ice under threat - update 4
https://arctic-news.blogspot.com/2023/06/arctic-sea-ice-under-threat-update-4.html

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

• 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

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

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

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


Friday, June 23, 2023

Arctic sea ice under threat - update 4

The image below, created by Eliot Jacobson, shows the North Atlantic sea surface temperature anomaly through June 20, 2023 (versus 1982-2023 mean).

The image below, created by Eliot Jacobson, shows the North Atlantic sea surface temperature on June 21, for the years 1982-2023.

The image below shows that the North Atlantic sea surface temperature was 23.3°C on June 21, 2023 (on the black line), 0.9°C higher than the 22.4°C on June 21, 2022 (on the orange line). A record high of 24.9°C was reached on September 4, 2022, even while La Niña then was suppressing the temperature, whereas now there's an El Niño.

[ click on images to enlarge ]

Global sea ice extent was at a record low for the time of year on June 23, 2023, i.e. only 21.57 million km², as illustrated by the image below.

[ click on images to enlarge ]

Contributing to this is very low Antarctic sea ice extent. The image below shows Antarctic sea ice extent up to June 23, 2023. Values in the column on the left are for February 16; Antarctic sea ice extent reached a record minimum on February 16, 2023. Values in the column on the right are for June 23. Highlighted are three years: 2023 (red), 2022 (blue) and 2016 (black). Antarctic sea ice extent was also very low at the end of the year 2016, which was a strong El Niño year, yet extent was even lower at the very end of the year in 2022, even though that was during a La Niña.


The image on the right, adapted from NOAA, shows ocean heat moving toward the Arctic along the path of the Gulf Stream on June 21, 2023, while sea surface temperatures on the map are as high as 32.5°C.

In addition, the Jet Stream is strongly deformed, and this threatens to strengthen heatwaves extending over the Arctic Ocean and causing hot water from rivers to enter the Arctic Ocean, and to strengthen storms accelerating the flow of ocean heat into the Arctic Ocean, while fires and storms contribute to darkening of the sea ice, further speeding up its demise.

The danger is that, as El Niño strengthens and as ocean heat keeps entering the Arctic Ocean from the Atlantic Ocean and the Pacific Ocean, a huge amount of heat will abruptly be pushed into the Arctic Ocean. 

This danger is illustrated by the image on the right, showing the Jet Stream pushing wind at a speed of 126 km/h (78 mph) up through Fram Strait (at the green circle) into the Arctic Ocean on June 21, 2023.

This situation threatens to cause 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.

This in turn threatens to trigger methane eruptions from the seafloor of the Arctic Ocean, a threat that has been described many times before, such as here, here and here.

[ 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, thus also 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

• Arctic sea ice under threat - update 1

• Arctic sea ice under threat - update 2

• Arctic sea ice under threat - update 3

• Eliot Jacobson - North Atlantic sea surface temperature anomaly through June 20, 2023

• Eliot Jacobson - North Atlantic sea surface temperature on June 21, for the years 1982-2023
https://twitter.com/EliotJacobson/status/1672232859409723392/photo/1

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

• 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

• Wetland emission and atmospheric sink changes explain methane growth in 2020 - by Sushi Peng et al. 

• NOAA - sea surface temperature

• Nullschool.net

• Latent Heat

• Albedo

• Extinction

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

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