Earth has two poles, the North Pole (Arctic) and the South Pole (Antarctic), and there are some important differences between them.
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| [ Ocean Currents at 5 meter below the sea surface on July 2, 2026 ] |
The South Pole is dominated by Antarctica, a huge landmass. By contract, at the center of the North Pole is open water, the Arctic Ocean.
Furthermore, while warm water surrounds Antarctica, the Antarctic Circumpolar Current (ACC) acts as a barrier, keeping ocean heat away from the Antarctic coasts and the sea ice. By contrast, the flow of water in the Atlantic Ocean is dominated by the Atlantic Meridional Overturning Circulation (AMOC). Water in the North Atlantic Ocean is funneled through a passage in between North America and Europe that aligns with prevailing winds from the Equator toward the North Pole and the deflection caused by the Coriolis Effect, created by the rotation of Earth, thus strengthening the flow of ocean heat into the Arctic Ocean underneath the sea ice.
Arctic
Ocean heat is mainly moving from the North Atlantic through the Fram Strait into the Arctic Ocean and - to a lesser extent - from the North Pacific through the Bering Strait into the Arctic Ocean.
The image below, from an earlier post, shows sea surface temperatures as high as 34°C (or 93.2°F) around North America on August 22, 2026, illustrating geographic conditions facilitating the Gulf Stream to push ocean heat north in the Atlantic Ocean toward the Arctic.
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| [ Sea surface temperatures as high as 34°C, click on images to enlarge ] |
While wind strengthens as temperatures rise, polar amplification of global warming is narrowing the temperature difference between the Equator and the Poles, and this can slow down and distort wind patterns such as the Jet Stream and ocean currents such as the Atlantic Meridional Overturning Circulation (AMOC) and the Southern Meriodinal Ocean Circulation (SMOC). Slowing down of AMOC can result in less heat arriving in the Arctic Ocean.
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| [ click on images to enlarge ] |
Stronger heatwaves and storms over land can also cause increasingly large amounts of freshwater to get added to the surface of the Arctic Ocean in the form of water from rivers and from runoff from land, as illustrated by the image below, from an earlier post. Less salty water can contribute to a temporary slowing down of Arctic sea ice melting, but given the speed at which the ocean heat keeps rising, such a slowdown looks set to be overwhelmed soon and huge melting of sea ice threatens to return with a vengeance, i.e. abruptly, when the threshold gets crossed due to rising sea surface temperatures.
Temperatures of the sea surface are very high, as much as 13°C or 23.3°F higher than 1981-2011 on September 4, 2026, in the Gulf of Ob (green circle on the above image). The image also shows that the cold area that was previously visible south of Greenland got overwhelmed by the huge rise in ocean heat, as the 2026/2027 El Niño keeps gaining in strength and as Earth's Energy Imbalance keeps increasing, as illustrated by the image below, by Leon Simons.
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| [ from earlier post ] |
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| [ Saltier water, less sea ice, from earlier post ] |
Freshening of the sea surface can slow down the melting of sea ice by making a maximum difference of 2°C (as depicted by the image on the right). The less salt the water contains, the higher its melting point. Seawater typically has a salinity of about 3.5% (35 grams of salt per liter of water). Sea ice starts melting when the temperature rises to about -2°C (28.4°F). By contrast, freshwater remains frozen as long as the temperature remains below 0°C (32°F).
In other words, increased freshwater can hold back Arctic sea ice decline, but as temperatures keep rising, this can only be a temporary delay.
Given the speed at which the temperature of the water of the Arctic Ocean keeps rising, a slowdown looks set to be overwhelmed soon and huge melting of sea ice looks set to return abruptly as sea surface temperatures keep rising in line with the 2026 El Niño. More ocean heat entering the Arctic Ocean subsequently threatens to cause abrupt destabilization of sediments containing huge amounts of methane.
How much slowing down could freshening of the water of the Arctic Ocean cause for the melting of Arctic sea ice? The above image shows that salt content could theoretically make a maximum difference of 2°C, but that would be going from one extreme end to the opposite end. In practice, the difference will be less than 1°C. If the temperature of the global ocean surface kept rising at the current pace, how long would it take for the rise to overwhelm the potential freshening effect of the Arctic Ocean? The image below shows an extension of a 5-year Lowess smoothing trend of NASA data, illustrating how long it may take for a difference of 1°C to eventuate.
The image below, adapted from the Danish Meteorological institute, shows that while the Arctic sea ice volume maximum in April 2026 was the lowest on record, relatively little melting occurred since, so the 2026 minimum was just above the record minima of 2024 and 2025.
There are large seasonal variations that also have an impact. In October, sea ice will have sealed off the water of the Arctic Ocean from precipitation, so no more fresh water will be added to the Arctic Ocean due to rain falling or snow melting on the water. In October, temperatures on land around the Arctic Ocean will have fallen below freezing point, so less fresh water will flow from glaciers and from melting snow and ice from land into the Arctic Ocean. At that time of year, melting of sea ice has stopped, so no more fresh water from melting sea ice gets added to the Arctic Ocean.
Furthermore, as the sea ice seals off the Arctic Ocean, there will be less transfer of Ocean heat to the atmosphere over the Arctic Ocean, which can result in further heating up of the water of the Arctic Ocean, which is very shallow in many places, making it easy for Ocean heat to reach and penetrate sediments at the seafloor.
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| Pingos and conduits. Hovland et al. (2006) |
Warm water can cause melting of the ice that is held in cracks and passages in sediments at the seafloor of the Arctic Ocean, allowing methane contained in the sediment to escape.
The image on the right, from a study by Hovland et al., featured in an earlier post. Hydrates can be present at the end of conduits leading to Pingos that were formed in the sediment where methane did escape from hydrates in the past. Heat can travel down such conduits relatively fast, warming up the ice in the Pingos and conduits, destabilizing hydrates and resulting in huge abrupt releases of methane from the hydrates, as well as from methane held in the form of free gas underneath such hydrates.
The huge amount of ocean heat present in the Pacific Ocean at the Equator is illustrated by the image below, adapted from NOAA and from an earlier post, with subsurface temperature anomalies of as much as +10.0°C at 100 m depth.
An earlier post describes that there are multiple mechanisms behind heating up of water of the Arctic Ocean, with the danger that a Double Blue Ocean Event will occur soon.
Antarctic
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| [ Precipitable water anomalies over Antarctica ] |
In the Southern Hemisphere, water evaporates from the Southern Ocean and part of the resulting precipitation falls on the Antarctic ice sheet, thickening the snow layer, as illustrated by the image on the right, from an earlier post and showing a forecast of high precipitable water anomalies over Antarctica on August 20, 2025.
As a result, the Southern Ocean surface is getting more salty. Saltier surface waters sink more readily, allowing heat from the deep to rise, which can melt Antarctic sea ice from below, even during winter, making it harder for ice to reform. This vertical circulation also draws up more salt from deeper layers, reinforcing the cycle, as discussed in earlier posts such as this one.
The dramatic decrease in sea ice around Antarctica looks set to continue long-term, as a feedback that is amplified by albedo loss, lower emissivity, loss of the sea ice's latent heat buffer, wind pattern changes and ocean current changes, ocean stratification, increased water vapor in the atmosphere and salinity increase of the sea surface of the Southern Ocean, as also discussed at the Antarctica page.
While the Antarctic methane danger has been described before, such as in this April 2013 post, the main focus of the Arctic-news blog has long been on the Arctic, in particular on the East Siberian Arctic Shelf (ESAS). More recently, research published in 2025 highlights that the situation in Antarctica is also dire, justifying an additional wider focus on global developments, as discussed on facebook and as discussed at the Antarctica page and in this post.
Conclusion
In conclusion, geographic differences result in different precipitation outcomes and this can in turn result in salinity differences that are behind different melting patterns. In both cases, there is a huge threat that methane will erupt in enormous volumes.
Links
• Extreme heat danger
• The 2026 El Niño
• NASA: Arctic Sea Ice Reaches 2026 Annual Minimum Extent
• Danish Meteorological institute - Arctic sea ice volume
• Cold freshwater lid on North Atlantic
• Saltier water, less sea ice
• Will humans go extinct soon?
• Extreme Heat Risk
• Focus on Antarctica
• Antarctica
