The combination image below shows sea surface temperatures for each of those years, with the location highlighted by a green circle, i.e.
2014: -0.8°C or 30.6°F
2015: 6.2°C or 43.2°F
2016: 8.3°C or 47.0°F
2017: 14.4°C or 57.9°F
2018: 16.6°C or 61.9°F
The situation reflects the rapid decline of Arctic sea ice over the years.
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| [ click on images to enlarge ] |
The image on the right shows the sea surface temperature on July 13, 2018, at that location. It was as warm as 16.9°C or 62.5°F near Svalbard.
This compares to a sea surface temperature of 4.9°C or 40.9°F in 1981-2011 at that location (at the green circle).
The image illustrates why sea ice has fallen dramatically in volume, especially so where sea currents push warm water from the Atlantic Ocean underneath the sea ice.
As the image below shows, Arctic sea ice volume on July 10, 2018, was at a record low for the time of the year.
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Latent heat can make that such disappearance can come abruptly. Latent heat is energy associated with a phase change, such as the energy absorbed by solid ice when it changes into water (melting). During a phase change, the temperature remains constant. Sea ice acts as a buffer that absorbs heat, while keeping the temperature at zero degrees Celsius. As long as there is sea ice in the water, this sea ice will keep absorbing heat, so the temperature doesn't rise at the sea surface.
The amount of energy absorbed by melting ice is as much as it takes to heat an equivalent mass of water from zero to 80°C.
Once the sea ice is gone, further heat must go elsewhere, i.e. it will typically raise the temperature of the water. The atmosphere will also warm up faster. More evaporation will also occur once the sea ice is gone, which will cool the sea surface and warm up the atmosphere (technically know as latent heat of vaporization). As temperatures in the Arctic are rising faster than at the Equator, the Jet Stream will change, making it easier for warm air to enter the Arctic. More clouds will form over the Arctic, which will reflect more sunlight into space, but which will also make that less outward IR radiation can escape into space over the Arctic, with a net warming effect.
A warmer Arctic comes with the danger of rapid warming of water in rivers that end in the Arctic Ocean, which will thus further wamr up the Arctic Ocean.
One huge danger is that, as the buffer disappears that until now has consumed huge amounts of ocean heat, and the Arctic Ocean keeps warming, further heat will reach methane hydrates at the seafloor of the Arctic Ocean, causing them to get destabilized and release methane.
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| [ The Buffer has gone, feedback #14 on the Feedbacks page ] |
Similar albedo changes are likely to take place over land in the Arctic soon thereafter. Adding up all warming elements associated with disappearance of the sea ice can result in an additional global warming of several degrees Celsius.
The situation is dire and calls for comprehensive and effective action, as described in the Climate Plan.
Links
• Can we weather the Danger Zone?
https://arctic-news.blogspot.com/2018/07/can-we-weather-the-danger-zone.html
• How much warmer is it now?
https://arctic-news.blogspot.com/2018/04/how-much-warmer-is-it-now.html
• Feedbacks
https://arctic-news.blogspot.com/p/feedbacks.html
• How much warming have humans caused?
https://arctic-news.blogspot.com/2016/05/how-much-warming-have-humans-caused.html
• The Threat
https://arctic-news.blogspot.com/p/threat.html
• Extinction
https://arctic-news.blogspot.com/p/extinction.html
• Climate Plan
https://arctic-news.blogspot.com/p/climateplan.html
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