Showing posts with label North Atlantic. Show all posts
Showing posts with label North Atlantic. Show all posts

Sunday, September 22, 2024

High temperatures despite La Niña?


[ click on images to enlarge ]
Temperatures remain extremely high, even though La Niña conditions may already be present, as illustrated by the above image, showing sea surface temperature anomalies (SSTA) versus 1981-2011. 

The image on the right shows the Northern Hemisphere (-90°,90°) with SSTA as high as 24.8°F (13.8°C) in Hudson Bay (green circle) on Sep. 22, 2024. There are only very few cold spots, while massive amounts of ocean heat are present in the North Atlantic and the North Pacific. 

On September 26, 2024, the sea surface temperature (60°S-60°N, 0-360°E) was 20.97°C, a record high for the time of year and 0.83°C above the 1982-2010 average, as illustrated by the image below. 


North Atlantic (0-60°N 0-80°W) sea surface temperature anomalies remained high and reached a record high for the time of year on September 26, 2024, as illustrated by the image below (SSTA vs 1882-2011).


The image below shows that the North Atlantic sea surface reached a temperature of 24.97°C (76.95°F) on September 22, 2024, a record high for the time of year and 1.07°C (1.926°F) above 1991-2020 or 1.3°C (2.34°F) above 1981-2010. The image also shows a 0.23°C difference in anomalies when shifting the base by a decade, indicating that the anomaly would be much higher when calculated from a pre-industral base. 
 

The image below, by Brian McNoldy shows that ocean heat content in the Gulf of Mexico was at a record high for the time of year on September 23, 2024. 


La Niña conditions may already be present

The black dashed line in the image below, adapted from NOAA, indicates a transition to La Niña in October 2024, persisting through Jan-Mar 2025.


The image below, adapted from NOAA, illustrates that El Niño conditions were present from June 2023 through April 2024, and that ENSO-neutral started in May 2024.


While El Niños typically occur every 3 to 5 years, as NOAA explains, El Niños can occur as frequently as every two years, as happened in 2002, 2004 and 2006, as the above image shows. Moving from the bottom of a La Niña to the peak of a strong El Niño could make a difference of more than 0.5°C.

The danger is that we could move into a new El Niño in 2025, while sunspots move toward a peak and while temperatures remain high due to Earth's high Energy Imbalance and due to feedbacks, as discussed in a recent post. The peak in sunspots in this cycle is expected to occur in July 2025, at which time Arctic sea ice may disappear, triggering further feedbacks, leading to a huge temperature rise by end 2026 that could drive humans into extinction. 


The above image from Copernicus illustrates that, for many months, the temperature anomaly has been high, i.e. about 0.8°C (± 0.3°C) above the 1991-2020 average and much more when compared to a pre-industrial base, with little or no sign of a return to earlier temperatures.


The above image illustrates that global daily mean near-surface (2m) air temperature anomalies vs 1991-2020 (Copernicus) have been above about 0.5°C for almost 16 consecutive months, i.e. since El Niño started (in June 2023, blue shade) and under ENSO-neutral conditions (starting May 2024). La Niña is expected to start October 2024 and the added trends point at a continued rise.   

The danger of methane hydrates getting destabilized

[ click on images to enlarge ]
The image on the right shows sea surface temperatures as high as 32.6°C on September 21, 2024. The image also shows the Gulf Stream pushing ocean heat toward the Arctic Ocean.

This flow of ocean heat can be accelerated by storms that are amplified due to high sea surface temperatures, deformation of the Jet Stream and a freshwater lid forming at the surface of the North Atlantic. 

At the same time, Arctic sea ice starts expanding rapidly in extent at this time of year, effectively sealing off the Arctic Ocean and making it hard for heat to get transferred from the surface of the Arctic Ocean to the atmosphere. 

As discussed in earlier posts, Arctic sea ice has become very thin, diminishing its capacity to act as a buffer that consumes ocean heat entering the Arctic Ocean from the North Atlantic. 

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 the same. Once all ice has turned into water, all subsequent energy goes into heating up the water, and will do so at 4.18 J/g for every 1°C the temperature of the water rises.

[ The Latent Heat Buffer ]
Ocean heat that was previously consumed by melting the sea ice, can no longer get consumed by melting of the sea ice once Arctic sea ice has become very thin, and further incoming heat instead gets absorbed by the Arctic Ocean, rapidly pushing up the temperature of the water of the Arctic Ocean.

The danger is that, as the water of the Arctic Ocean keeps heating up, more heat will reach the seafloor and destabilize methane hydrates contained in sediments at the seafloor, resulting in eruptions of huge amounts of methane. 

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 ]

Eruptions from hydrates occur at great force, since the methane expands 160 times in volume when it vaporizes, 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, which especially applies to the many areas where the Arctic Ocean is very shallow. Furthermore, the atmosphere over the Arctic contains very little hydroxyl, resulting in methane persisting in the air over the Arctic much longer than elsewhere.

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

• Nullschool
https://earth.nullschool.net

• Climate Reanalyzer
https://climatereanalyzer.org

• Ocean Heat Content - by Brian McNoldy
https://bmcnoldy.earth.miami.edu/tropics/ohc

• NOAA - Climate Prediction Center - ENSO: Recent Evolution, Current Status and Predictions
https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.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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Saturday, April 22, 2023

High sea surface temperature in North Atlantic

SST World (60S-60N)

On April 20, 2023, sea surface temperatures (between 60°South and 60°North) had been at 21°C or higher for as many as 32 days. Such temperatures are unprecedented in the NOAA record that goes back to 1981.


On April 4, the sea surface temperature in 2023 (black line) was as much as 0.3°C higher than in 2022 (orange line) and we're only just entering the upcoming El Niño.


SST North Atlantic

The situation is especially critical in the North Atlantic. Vast amounts of ocean heat in the North Atlantic are moving toward the Arctic, threatening to cause rapid melting of Arctic sea ice and thawing of permafrost. Last year, North Atlantic sea surface temperatures reached a record high of 24.9°C in early September and, as illustrated by the image below, the North Atlantic sea surface temperature on April 20 was as much as 0.5°C higher in 2023 (black) than in 2022 (orange).
 

As we're moving into the upcoming El Niño, the Arctic Ocean can be expected to receive more and more heat over the next few years, i.e. more heat from direct sunlight, more heat from rivers, more heat from heatwaves and more ocean heat from the Atlantic Ocean and the Pacific Ocean.

Temperature rise

As illustrated by the image below, the difference in global temperatures (Land+Ocean) between November 2022 and March 2023 is already about half a degree Celsius and we are not even in an El Niño yet.

[ from earlier post ]

Rising temperatures threaten to trigger massive loss of sea ice (and loss of albedo) and eruptions of methane from the seafloor of the Arctic Ocean. Over the next few years, feedbacks threaten to start kicking in with increased ferocity and important tipping points threaten to get crossed, such as the latent heat tipping point and the seafloor methane tipping point. 

[ from earlier post ]

El Niño can be expected to reach its full strength within a few years, with a maximum possible in 2026. Altogether, the rise from pre-industrial could be more than 18.44°C by 2026. Meanwhile, humans are likely to go extinct with a rise of 3°C and most life on Earth will disappear with a 5°C rise.

Conclusion

In conclusion, everyone is encouraged to support and share this Climate Emergency Declaration.


Links

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

• Temperatures rising fast March 2023

• Sea surface temperature at record high
• Climate Emergency Declaration
https://arctic-news.blogspot.com/p/climate-emergency-declaration.html




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