From CLIMATE DEPOT
By Marc Morano
https://arcfieldweather.com/blog/2024/7/30/715-am-another-summer-with-nearly-normal-temperatures-in-the-arctic-region-continues-a-long-term-trend- when-the-season-melts
According to Meteorologist Paul Dorian
Summary
Summer is more than half over in the Arctic region and overall temperatures this season are repeating a pattern that started several years ago as they run at near-normal levels that happen to be quite close to the freezing mark. The cold winter in the Arctic has shown above-normal temperatures in the Arctic region in a pattern that has also been very consistent in recent years. These are the temperatures in the summer months of June, July, and August, but they are the most important when it comes to Arctic sea ice because this is the melting season in the region. As long as the temperature remains close to normal during the summer (melt), the chance of reducing sea ice will be limited. Indeed, due to consistent summer temperature trends in recent years, Arctic sea ice has shown resilience in terms of size and volume. One explanation for the persistent temperature pattern in the Arctic region with near-normal summer conditions and warmer-than-normal conditions in the other nine months of the year (ie, winter) is an increase in the amount of water vapor in the atmosphere.
Arctic temperatures and their impact on sea ice
Temperatures have followed a continuous trend in the Arctic region over the past several years, in fact, going back to the beginning of the 21st century. In particular, temperatures have been running at near-normal levels during the important summer (melt) season in June, July, and August and usually at higher levels than normal for the remaining nine months.
Temperatures are almost normal in the summer months of June, July and August usually at a level close to or just above the freezing mark and as long as they remain in the melting season (summer), the possibility for any significant drop-off in the Arctic sea ice. will be limited. Above-normal temperatures the other nine months of the year have minimal impact on the melting of Arctic sea ice because they are usually below the freezing mark. Indeed, with reliable temperature trends in recent years, Arctic sea ice is more resilient in terms of size and volume.
Arctic sea ice extent has been running at below-normal levels since the mid-1990s when there was a significant shift in the Atlantic Multidecadal Oscillation (AMO) to one with warmer-than-normal sea surface temperatures in the North Atlantic Ocean. Arctic sea ice continued to decline following these changes and reached its lowest point in 2012 at levels not seen before during the satellite era going back to the late 1970s. Since then, Arctic sea ice has remained stable with a general downward trend over the past decade.
In addition to sea ice depthan important climate indicator to monitor is sea ice volume because it depends on the thickness and extent of the ice. Arctic sea ice volume is difficult to monitor continuously because observations from satellites, submarines and field measurements are all limited in space and time. As a result, one of the best ways to estimate sea ice volume is to use numerical models that use all available observations. One such computer model comes from the University of Washington and is called the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS, Zhang and Rothrock, 2003). Arctic sea ice volume derived from this model shows a steady downward trend from the mid-1990s until the lowest point reached in 2012. Since then, Arctic sea ice volume has shown resilience with a general downward trend over the past few years.
Possible role of water vapor
One possible explanation for the behavior of temperatures in the Arctic region over the past few decades is related to the increase in water vapor in the atmosphere. Overall, water vapor content has been higher than normal in the Arctic region over the past few decades due to warmer than normal sea surface temperatures in the North Atlantic (AMO positive) and Pacific Ocean (multiple). El Nino event).
Due to warmer than normal water temperatures, evaporation is increased and this will produce more water vapor in the atmosphere. Increased water vapor will have a greater effect on temperature in a cold, dry atmosphere and less effect in a warmer, more humid environment.. In other words, the overall increase in water vapor could lead to warmer-than-normal temperatures during the cold winter in the Arctic region when it is normally cold and dry, and may have little, if any, effect during the summer. , summer is more humid (melting).
Meteorologist Paul Dorian
Archfield
arcfieldweather.com
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