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Home / Science / Where is the sea ice?3 reasons for the abnormally late freezing of the Arctic and its importance

Where is the sea ice?3 reasons for the abnormally late freezing of the Arctic and its importance



With the setting of the sun and the advent of polar darkness, until now, the Arctic Ocean is usually crushed by sea ice along the coast of Siberia. But this year, the water is still open.

I have been an Arctic climate scientist since the 1980s, and the head of the US National Snow and Ice Data Center since 2008. I have been observing changes in the region. I can tell you that this is abnormal. There is much more heat in the ocean than in the past, so that the growth pattern of autumn ice has been completely destroyed.

To understand what is happening with sea ice this year and why there are problems, let̵

7;s look back at summer and the Arctic Ocean itself.

100 degrees summer in Siberia

The summer melting season in the Arctic starts earlier. In June, the Siberian heat wave pushed the temperature in Verkhoyansk, Russia to above 100 degrees Fahrenheit. This was the first time on record. The abnormal heat continued for several weeks throughout the Arctic.

Throughout the summer, the entire Arctic has the highest temperature since at least 1979, when satellite measurements began to provide data that could completely cover the Arctic.

With this heat, large areas of sea ice will melt early, and the melting triggers a feedback process: the loss of reflective sea ice is exposed to the dark open ocean, which easily absorbs the sun’s heat, thereby promoting more Too much ice melts.

By mid-July, the North Sea route along the coast of Russia was basically ice-free. For transportation interests, this may be a dream, but for the rest of the planet, it is bad news.

Warm diving underwater

The warm summer is only part of the explanation for this year’s abnormal sea ice levels.

Warm water from the Atlantic Ocean flows into the Arctic in the Barents Sea. This warmer, salty Atlantic water is usually quite deep under the more buoyant Arctic water on the surface. But recently, the water in the Atlantic Ocean has been rising. The heat in the Atlantic water helps prevent ice from forming and melting existing sea ice from below.

This is a process called “Atlantification”. Now, the ice layer is being affected by climate warming from the top and ocean warming at the bottom. This is really a double whammy.

Although we are still trying to catch up with all the processes that led to Atlanticization, it is here and it may become stronger.

The impact of climate change on sea ice

The background to all this is global climate change.

With the increase in global temperature, the extent and thickness of Arctic sea ice has been declining. This year, when ice reached its lowest level in September, it was the second lowest on record, after 2012.

With the loss of ice in the Arctic and the oceans absorbing more solar radiation, global warming has intensified. This can affect ocean circulation, weather patterns and Arctic ecosystems throughout the food chain, from phytoplankton all the way to top predators.

On the Atlantic side of the Arctic, this year’s open water has expanded to within 5 degrees of the Arctic. The new Russian icebreaker Arktika is on its maiden voyage, sailing all the way to the North Pole easily. The purpose of its voyage is to test how the nuclear-powered ship handles thick ice, but most of the ice is packed in bulk, not the desired 3-meter thick ice. It is only a little over 1 meter thick and has almost no resistance.

In order for sea ice to accumulate again this year, the upper layers of the Arctic Ocean need to lose the excess heat absorbed in summer.

The patterns of regional anomalies in ice area are different each year, reflecting influences such as regional patterns of temperature and wind. But today, due to the increase in global temperature, it is superimposed on the overall thinning of the ice. If the same atmospheric pattern caused the loss of Siberia’s large amount of ice this year to occur 30 years ago, the impact will be much smaller, because ice is more elastic than then and may be hit hard. Not anymore.

Will sea ice detonate?

The decay of the Arctic sea ice sheet shows no signs of stopping. However, sea ice may not have a clear turning point.

Research so far shows that we will maintain the current development trend, because the thickness of ice is thinner and thinner than before, so the amount of ice is declining, and the weather system is more likely to destroy ice.

Bigger picture

The events in the Arctic this year are only part of the 2020 climate change story.

Since January, the global average temperature has been at or near the highest level in history. The West is hot and dry, which is the perfect secret for large-scale wildfires. The warm waters of the Gulf of Mexico helped propel more tropical storms than letters in the Atlantic Ocean. If you have been ignoring climate change and hope that climate change will disappear, now is the right time to pay attention.


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