Arctic amplification: Why Greenland’s ice is quickly melting - TomoNews
- 8 years ago
CORNELL GLACIER, GREENLAND — During summer 2015, Greenland experienced its highest rate of glacier melt. A new study, published on June 9 in “Nature Communications,” shows the record-high melt is linked to the anticipated effects of a phenomenon known as Arctic amplification.
Arctic amplification refers to the faster warming of the Arctic compared to the rest of the Northern Hemisphere as sea ice disappears. It is fueled by a feedback loop: rising global temperatures are melting Arctic sea ice, leaving dark open water that absorbs more solar radiation, and that warms the Arctic even more.
According to the study, the atmosphere and the oceans, combined are contributing to the melting of vast ice sheets off the coast of northern Greenland.
The effects of Arctic amplification are unknown, but scientists believe it could change climates by slowing the jet stream, which circles the northern latitudes. Jet streams are narrow bands of strong winds in the upper atmosphere. They follow the boundaries of hot and cold air, and, in the Arctic’s case, keeps frigid polar air separated from warmer air in the south. A change in the jet stream could lead to significant changes in weather and temperatures across the world.
The new study showed evidence that the jet stream may be slowing as hypothesized. A slowdown in the jet stream would wilder swings and allow it to bend far more north than usual. The study found that during the warmest summer in Greenland, the jet stream was reached latitudes never before recorded that time of year.
The jet stream’s wacky northern upswing formed a blocking event — a stable, clockwise-circulating weather pattern — that hovered over Greenland. The high pressure system, called a cut-off high, drew in warm, moist air from lower latitudes, which led to the warmer temperatures and shockingly high melting.
Researchers including those at NASA are currently tracking climate and ice melt patterns in Greenland. The Greenland ice sheet, earth’s second largest after Antarctica, holds enough ice that, if it were to melt entirely, it would raise average global sea level by about seven meters. And the melt could lead to ocean warming, world-wide.
NASA researchers, as the first phase of the Oceans Melting Greenland (OMG) project, are mapping Greenland’s seafloor in order to better understand how warm water is melting glaciers from below in order to find solutions to preventing rapid loss of sea ice. The project commenced in 2015 and will continue through 2020 in hopes of providing more data and insight into Greenland’s glacier melt.
Arctic amplification refers to the faster warming of the Arctic compared to the rest of the Northern Hemisphere as sea ice disappears. It is fueled by a feedback loop: rising global temperatures are melting Arctic sea ice, leaving dark open water that absorbs more solar radiation, and that warms the Arctic even more.
According to the study, the atmosphere and the oceans, combined are contributing to the melting of vast ice sheets off the coast of northern Greenland.
The effects of Arctic amplification are unknown, but scientists believe it could change climates by slowing the jet stream, which circles the northern latitudes. Jet streams are narrow bands of strong winds in the upper atmosphere. They follow the boundaries of hot and cold air, and, in the Arctic’s case, keeps frigid polar air separated from warmer air in the south. A change in the jet stream could lead to significant changes in weather and temperatures across the world.
The new study showed evidence that the jet stream may be slowing as hypothesized. A slowdown in the jet stream would wilder swings and allow it to bend far more north than usual. The study found that during the warmest summer in Greenland, the jet stream was reached latitudes never before recorded that time of year.
The jet stream’s wacky northern upswing formed a blocking event — a stable, clockwise-circulating weather pattern — that hovered over Greenland. The high pressure system, called a cut-off high, drew in warm, moist air from lower latitudes, which led to the warmer temperatures and shockingly high melting.
Researchers including those at NASA are currently tracking climate and ice melt patterns in Greenland. The Greenland ice sheet, earth’s second largest after Antarctica, holds enough ice that, if it were to melt entirely, it would raise average global sea level by about seven meters. And the melt could lead to ocean warming, world-wide.
NASA researchers, as the first phase of the Oceans Melting Greenland (OMG) project, are mapping Greenland’s seafloor in order to better understand how warm water is melting glaciers from below in order to find solutions to preventing rapid loss of sea ice. The project commenced in 2015 and will continue through 2020 in hopes of providing more data and insight into Greenland’s glacier melt.