Behind the Forecast: 2020 Arctic Sea Ice near record low

Listen to Science Behind the Forecast with Meteorologist Tawana Andrew every Friday on 89.3 WFPL at 7:45 a.m.
Published: Oct. 2, 2020 at 9:06 AM EDT
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LOUISVILLE, Ky. (WAVE) - Arctic sea ice has reached record low levels after the summer melt season. It was the second-lowest level after the one seen in 2012.

The U.S. National Snow and Ice Data Center (NSIDC) announced that the sea ice extent was 3.74 million square kilometers (1.44 million square miles) on September 15.

The last 14 years (2007 to 2020) have featured some of the lowest levels of Arctic sea ice in the 42-year history of the satellite record.

High water and air temperatures are just a few of the causes of this summer’s sea ice loss; these warmed the ice from both above and below. The Siberian tundra saw temperatures near and above 100° in June. One month later, hundreds of wildfires ravaged the landscape.

The process of Arctic amplification occurs because light-colored sea ice, which reflects heat into space (a high albedo), is replaced by dark ocean water when it melts, which absorbs heat. The warm water melts more ice, which allows for even more warm ocean water to absorb additional heat, continuing the vicious cycle.

Temperatures across the Arctic are rising more than twice as fast as the global average, according to scientists at the National Center for Atmospheric Research (NCAR). A recent study from these scientists shows that the Arctic has started to transition to a new climate.

The declining sea ice in the Arctic has far-reaching consequences.

Our weather is a result of the ocean and atmosphere transporting heat from the equator towards the poles. Changes in the amount of sea ice near the poles alter the temperature in these areas, which in turn, may affect atmospheric and oceanic circulations.

Thermohaline circulation is the process by which ocean currents transport heat from the equator to the poles through a heat- and a saline-driven process. Warm water travels from the equator northward along the ocean’s surface, cooling as it travels, eventually becoming dense and heavy before sinking. The cold water then travels southward along with the lower levels of the ocean, rising near the equator.

Melting sea ice puts more freshwater into the oceans. Freshwater is less dense compared to saltwater and is less likely to sink. If it doesn’t sink, that inhibits the thermohaline circulation.

The Gulf Stream is a strong warm ocean current that carries warm water from the Gulf of Mexico, up the eastern coast of North America towards Iceland and Europe. The warm water contributes to the milder climate seen in Europe compared to parts of Canada in the same latitude. Adding freshwater into the Gulf Stream could not only have ramifications for Europe’s climate but also around the world.

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