UNIVERSITY OF ALASKA FAIRBANKS
A new study shows that increased heat from Arctic rivers is melting sea ice in the Arctic Ocean and warming the atmosphere.
The study published this week in Science Advances was led by the Japan Agency for Marine-Earth Science and Technology, with contributing authors in the United States, United Arab Emirates, Finland and Canada.
According to the research, major Arctic rivers contribute significantly more heat to the Arctic Ocean than they did in 1980. River heat is responsible for up to 10% of the total sea ice loss that occurred from 1980 to 2015 over the shelf region of the Arctic Ocean. That melt is equivalent to about 120,000 square miles of 1-meter thick ice.
“If Alaska were covered by 1-meter thick ice, 20% of Alaska would be gone,” explained Igor Polyakov, co-author and oceanographer at the University of Alaska Fairbanks’ International Arctic Research Center and Finnish Meteorological Institute.
Rivers have the greatest impact during spring breakup. The warming water dumps into the ice-covered Arctic Ocean and spreads below the ice, decaying it. Once the sea ice melts, the warm water begins heating the atmosphere.
The research found that much more river heat energy enters the atmosphere than melts ice or heats the ocean. Since air is mobile, this means river heat can affect areas of the Arctic far from river deltas.
The impacts were most pronounced in the Siberian Arctic, where several large rivers flow onto the relatively shallow shelf region extending nearly 1,000 miles offshore. Canada’s Mackenzie River is the only river large enough to contribute substantially to sea ice melt near Alaska, but the state’s smaller rivers are also a source of heat.
Polyakov expects that rising global air temperatures will continue to warm Arctic rivers in the future. As rivers heat up, more heat will flow into the Arctic Ocean, melting more sea ice and accelerating Arctic warming.
Rivers are just one of many heat sources now warming the Arctic Ocean. The entire Arctic system is in an extremely anomalous state as global air temperatures rise and warm Atlantic and Pacific water enters the region, decaying sea ice even in the middle of winter. All these components work together, causing positive feedback loops that speed up warming in the Arctic.
“It’s very alarming because all these changes are accelerating,” said Polyakov. “The rapid changes are just incredible in the last decade or so.”
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Authors of the paper include Hotaek Park, Eiji Watanabe, Youngwook Kim, Igor Polyakov, Kazuhiro Oshima, Xiangdong Zhang, John S. Kimball and Daqing Yang.
Maybe a new study, but old information. I pointed it out over a year ago:
https://1drv.ms/u/s!Aq1iAj8Yo7jNg0lXWzyccVHItf34
This explains why the ocean temperature reaches its peak in late July or early August rather than March when the peak ocean energy is reached. There is poorly mixed surface water that is not indicative of the ocean heat uptake.
Perhaps someone should explain to these twits how the rivers ARE part of the atmosphere while leaving boot-sole toe impressions opposite of curb impressions on their heads.
Loss of sea ice is a negative feedback. Sea ice insulates the ocean, its loss allows the system as a whole to lose heat.
Looks like during the 35 year period the majority of the “heat” was coming from the Russian side, and specifically from the Lena River Delta, emptying into the Laptev Sea.
Very little effect elsewhere.
It,s ocean currents not atmospheric processes that make ice caps grow or shrink. Down in Antarctica warm currents have been recently flowing toward the ice cap leading researchers to believe that this was both a sign and a mechanism of ice sheet warming and melt. But now it turns out its the opposite. Abtarctica is cooling, and the endless freezing catabatic winds are cooling the surrounding ocean and causing downwelling of cold dense water. The inflowing warm water is only doing so in reaction to the cold downwelling via undersea canyons around Antarctica.
Thus the increased warmer surface water flow toward Antarctica in recent years is in reaction to cooled Antarctic shelf water downwelling via underwater canyons. This means that Antarctic supply of cold deep water is increasing, envigourating the deep ocean Thermohaline Circulation. Here’s the link and the abstract:
https://advances.sciencemag.org/content/6/18/eaav2516.full
Warm Circumpolar Deep Water transport toward Antarctica driven by local dense water export in canyons
A. K. Morrison, McC. Hogg, M. H. England and P. Spence
Science Advances 01 May 2020:
Vol. 6, no. 18, eaav2516
DOI: 10.1126/sciadv.aav2516
Abstract
Poleward transport of warm Circumpolar Deep Water (CDW) has been linked to melting of Antarctic ice shelves. However, even the steady-state spatial distribution and mechanisms of CDW transport remain poorly understood. Using a global, eddying ocean model, we explore the relationship between the cross-slope transports of CDW and descending Dense Shelf Water (DSW). We find large spatial variability in CDW heat and volume transport around Antarctica, with substantially enhanced flow where DSW descends in canyons. The CDW and DSW transports are highly spatially correlated within ~20 km and temporally correlated on subdaily time scales. Focusing on the Ross Sea, we show that the relationship is driven by pulses of overflowing DSW lowering sea surface height, leading to net onshore CDW transport. The majority of simulated onshore CDW transport is concentrated in cold-water regions, rather than warm-water regions, with potential implications for ice-ocean interactions and global sea level rise.
And yet, according to NSIDC the Arctic is still covered with ice and snow, so just more lies and crapspew.