Tuesday, June 11, 2024

Arctic Sea Ice Alert

[ click on images to enlarge ]
Temperatures remain high, as illustrated by the above image, adapted from Copernicus

Meanwhile, El Niño is no longer prevalent. Instead, La Niña conditions are expected to be dominant soon, as illustrated by the NOAA ENSO update on the right. 

There are fears that self-amplifying feedbacks have taken over as the dominant drivers of the temperature rise, as discussed in earlier posts such as this one

Temperatures are getting very high in the Northern Hemisphere.

The image on the right shows maximum temperatures on June 10, 2024, with very high temperatures showing up over a large area around the North Pole.

Temperatures can be expected to keep rising. The image underneath shows a forecast of maximum temperature on June 13, 2024, with very high temperatures showing up on land around the Arctic Ocean, above 20°C in Alaska, parts of Siberia and on an area in Greenland.

This year, temperatures are extremely high, and this is especially the case for temperatures in the Gulf of Mexico and in the North Atlantic. 

Temperatures in the North Atlantic strongly affect Arctic sea ice.

As temperatures rise the Jet Stream gets more deforms, as discussed at the Jet Stream page.

Deformation of the Jet Stream enables heatwaves to extend over the Arctic, and to also result in strong wind over the North Atlantic, which can at times strongly accelerate the speed at which hot water flows toward the Arctic Ocean along that path of the Gulf Stream. 

The image on the right shows markedly higher temperatures than at similar latitudes in the path of the Gulf Stream, indicating a flow of heat from the Gulf of Mexico in the direction of the Arctic Ocean.

A deformed Jet Stream can temporarily speed up this flow, causing huge amounts of Ocean heat to get abruptly pushed into the Arctic Ocean in the path of the Gulf Stream. 

The image shows sea surface temperatures as high as 32.1°C on June 15, 2024. 

The image below shows high ocean heat content anomalies in the Gulf of Mexico, compared to the 2013-2023 mean, with anomalies recently reaching a new record high of above 20 KJ per cm². 

North Atlantic sea surface temperature anomalies have risen strongly over the past few years, as illustrated by the image below that highlights anomalies from 1951-1980 for May 2022, May 2023 and May 2024.

As illustrated by the image below, the North Atlantic sea surface temperature anomaly has moved higher recently.

After an astonishing rise in 2023, sea surface temperature anomalies fell for six months in the Northern Hemisphere, but they are rising again, threatening to cause dramatic sea ice loss over the next few months and destabilize sediments at the seafloor, resulting in huge amounts of methane erupting and abruptly entering the atmosphere.

Sea surface temperatures were actually rising on June 18, 2024, even though we may already be in a La Niña by now. The image below, created with a ClimateReanalyzer.org screenshot (text box added), shows that the sea surface (60°S–60°N, 0–360°E) reached a temperature of 20.94°C (69.69°F) on June 18, 2024, a record high for the time of year.

Heatwaves over land can also cause the water of rivers to heat up, with a lot of heat running off into the Arctic Ocean. 

The image on the right shows temperatures as high as 15.2°C in the Bering Strait on June 18, 2024.

As temperatures rise in the Northern Hemisphere, Arctic sea ice extent is falling, as illustrated by the image below. While this image shows that Arctic sea ice extent is not the lowest on record for the time of year, extent is only one way to measure the state of the sea ice. There are further ways to measure Arctic sea ice, such as area, concentration, volume and thickness.  

NSIDC explains the difference between extent and area: A simplified way to think of extent versus area is to imagine a slice of Swiss cheese. Extent would be a measure of the edges of the slice of cheese and all of the space inside it. Area would be the measure of where there is cheese only, not including the holes. Therefore, if you compare extent and area in the same time period, extent is always bigger.

Another measure is concentration. The image on the right, from NSIDC, shows Arctic sea ice concentration on June 18, 2024. 

Volume is another measure. The image below is adapted from the Danish Meteorological Institute and confirms that Arctic sea ice volume is at a record low for the time of year, as it has been for most of the year.  

Volume is calculated by multiplying thickness with concentration and with area, which implies that Arctic sea ice is very thin, as also indicated by the image below, adapted from the University of Bremen, which is combined with a NASA satellite image for comparison. 

The Uni of Bremen image on the left shows sea ice thickness in cm on June 11, 2024, with the added square corresponding to area covered by the NASA satellite image on the right, which also shows a lot of open water (black), while the white color can indicate either ice or it can be clouds.

The image below measures thickness by using both the brightness temperature data from ESA’s Soil Moisture and Ocean Salinity (SMOS) satellite and NASA’s Soil Moisture Active Passive (SMAP) satellite.
Lack of sea ice in the Lara Sea and the Laptev Sea (at top of the above images) is worrying, since these are shallow seas that hold huge amounts of carbon in sediments at the seafloor. Heat can penetrate these sediments and destabilize hydrates, resulting in eruption of huge amounts of methane.

Loss of sea ice comes with numerous further feedbacks that accelerate the temperature rise, and just the temperature rise itself comes with feedbacks such as more water vapor in the atmosphere. 

Surface precipitable water reached a record high of 27.139 kg/m² in July 2023, as illustrated by the image below, adapted from NOAA. Worryingly, a value of 26.138 kg/m² was reached in May 2024, much higher than the 25.378 kg/m² in May 2023, which raises fears that surface precipitable water will reach an even higher peak in 2024 than was reached in 2023.

Thawing permafrost can cause huge emissions of carbon dioxide, methane and nitrous oxide. Ominously, the image below shows high methane levels over Scandinavia, which could be the result of higher temperatures. 

As illustrated by the image below, adapted from Climate Reanalyzer, the temperature anomaly in Scandinavia was high in May 2024. 

Studies such as by Hubau (2020) warn that the uptake of carbon into Earth’s intact tropical forests peaked in the 1990s. Studies now warn that the Arctic has also changed from sink to source. 

A study by Del Vecchi et al. (2024) suggests that a gradual thawing of Arctic permafrost could release between 22 billion and 432 billion tons of carbon dioxide by 2100 if current greenhouse gas emissions are reined in — and as much as 550 billion tons if they are not.

An analysis by Ramage et al. (2024) concludes that Arctic terrestrial permafrost now emits more greenhouse gases than it stores, and the trend is likely to accelerate as temperatures keep rising in the Arctic. The highest carbon dioxide emissions over the 2000-2020 period came from inland rivers and wildfires. The non-permafrost wetlands exhaled the most methane, and dry tundra released the most nitrous oxide.

The prospect of further releases looks dire. The analysis gives estimates that the upper three meters of permafrost region soils store 1,000 Gt of soil organic carbon, while deeper deposits could store an additional amount of as much as 1,000 Gt C. The analysis concludes that the permafrost region is the largest terrestrial carbon and nitrogen pool on Earth.

Note that the joint CO₂e of emissions in this analysis only covers part of global emissions, e.g. the analysis excludes emissions from Arctic subsea permafrost and from oceans in general, from many mountain areas and from the Southern Hemisphere. The study also appears to have excluded emissions caused by anthropogenic disturbances such as clear-cutting, logging and fracking activities in the region, while calculations typically use a low global warming potential (GWP) for methane (100-year horizon).  

Miesner et al. (2023) warn that an additional 2822 Gt of organic carbon is stored in subsea Arctic shelf permafrost and Huang et al. (2024) warn that the top two meters of soil globally holds about 2300 Gt of inorganic carbon, which has been left out of environmental models, and 23 Gt of this carbon may be released over the next 30 years.

The transition from sink to source of the region is an important feedback of the temperature rise that is not fully reflected in many climate models. According to the IPCC, 14–175 Gt CO₂e (in carbon dioxide and methane) gets released per 1°C of global warming, which is likely to underestimate the situation by downplaying many feedbacks. Despite the dire situation, the IPCC keeps promoting less effective policies such as support for biofuel and tighter fuel efficiency standards, as discussed in earlier posts such as this 2022 one.

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.

• NOAA - National Centers for Environmental Information - Climate at a Glance - Global Time Series 

• Arctic Data archive System - National Institute of Polar Research - Japan

• NOAA - Global Monitoring Laboratory - Carbon Cycle Gases, Mauna Loa, Hawaii, U.S.

• NASA - datasets and images

• NSIDC - National Snow and Ice Data Center

• University of Bremen - Arctic sea ice

• Danish Meteorological Institute - Arctic sea ice volume and thickness

• NOAA - Physical Sciences Laboratory

• Copernicus

• Pre-industrial

• Extinction

• Copernicus - Climate Pulse

• NOAA - Physical Sciences Laboratory

• Tropical forests’ carbon sink is already rapidly weakening (news release) 
Asynchronous carbon sink saturation in African and Amazonian tropical forests - by Wannes Hubau et al. (2020)
Discussed at Facebook at: 

• Amplifying feedback loop between drought, soil desiccation cracking, and greenhouse gas emissions - by Farshid Vahedifard et al. (2024)
Discussed on facebook at

• Subsea permafrost organic carbon stocks are large and of dominantly low reactivity - by Frederieke Miesner et al. (2023) 

• Size, distribution, and vulnerability of the global soil inorganic carbon - by Yuanyuan Huang et al. (2024) 
Discussed at facebook at

• Biodiversity loss reduces global terrestrial carbon storage - by Sarah Weiskopf et al. (2024) https://www.nature.com/articles/s41467-024-47872-7
Discussed at Facebook at:

• Permafrost extent sets drainage density in the Arctic - by Joanmarie Del Vecchi et al (2024)
Discussed at Facebook at:

• IPPCC AR6 Workgroup 1 Frequently Asked Questions

• Temperature rise may soon accelerate even more

• nullschool

• Feebacks in the Arctic

• Jet Stream

• Cold freshwater lid on North Atlantic

• Arctic Ocean Feedbacks

• Arctic sea ice set for steep decline

• Transforming Society

• Climate Plan

• Climate Emergency Declaration