In July 2012, water from the Mackenzie River in Canada enters the blue Arctic Ocean. The white part of the upper part of the photo is mostly sea ice, while the lower part is clouds above the ground. Credit: NASA Earth Observatory
A new study has shown that rising heat from Arctic rivers is melting sea ice in the Arctic Ocean and warming the atmosphere.
The study was published this week Science progress Led by the Japan Agency for Marine-Earth Sciences and Technology, with authors contributing to the United States, United Arab Emirates, Finland and Canada.
According to research, major Arctic rivers contribute more heat to the Arctic Ocean than in the 1980s. River heat is responsible for about 10% of the total sea ice in the Arctic shelf between 1980 and 2015. Ocean. It melts about 120,000 square miles of ice about 1,000 meters thick.
“If Alaska is covered with 1-meter thick ice, 20% of Alaska will be covered,” explains Igor Polikov, a co-author and oceanographer at the University of Alaska’s Fairbanks International Arctic Research Center and Finnish Meteorological Logical Institute.
Rivers are most affected during the spring break. Warm water merges into the ice-covered Arctic Ocean and spreads beneath the ice, decaying. Once the sea ice melts, the warm water begins to warm the atmosphere.
Research has shown that the heat energy of a river enters the atmosphere more than the ice melts or warms the ocean. Air is mobile, meaning that river heat can affect areas of the Arctic away from the river delta.
This picture shows the relative proportions of the temperature caused by the Arctic rivers, with the heat source in orange and the heat sinking in turquoise. In spring, rivers flow into the Arctic Ocean, heating the water and melting sea ice, which in turn warms the atmosphere. As reflection ice disappears, Black Sea water absorbs more heat and more sea ice melts. Credit: Graphic Accepted from Science Advances Paper
Its impact was greatest in the Siberian Arctic, where many large rivers flow over a relatively shallow shelf area, extending about 1,000 miles along the coast. The Mackenzie River is the only major river in Canada to melt sea ice near Alaska, but smaller rivers in the state also cause heat.
Polikov expects rising global air temperatures to warm Arctic rivers in the future. As rivers warm up, more heat will flow into the Arctic Ocean, more ocean ice will melt, and Arctic warming will accelerate.
Rivers heat the Arctic Ocean, the only source of heat. The entire Arctic system is in an extremely inconsistent state as global air temperatures rise and warm Atlantic and Pacific waters enter the region, causing sea ice to erode even in mid-winter. All of these components work together, resulting in positive feedback loops in the Arctic.
“It’s very worrying because all these changes are dynamic,” Polikov said. “Rapid change is simply unbelievable in the last decade or so.”
Moorings of the Arctic Ocean will shed light on the loss of winter sea ice
Rising river heat fluxes reduce ice in the Arctic Ocean and stimulate sea and atmospheric temperatures Science progress (2020). DOI: 10.1126 / sciadv.abc4699, advances.sciencemag.org/content6 / 45 / eabc4699
Provided by the University of Alaska Fairbank
Testimonial: Rivers melt Arctic ice, warm air and sea (2020, November 6) 7 November 2020 https://phys.org/news/2020-11-rivers-arctic-ice-air-ocean.html
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