Simulations Explain Greenland’s Slower Summer Warming
Climate changes in the tropical Pacific have momentarily put the brakes on fast warming and ice melting in Greenland.
Researchers at Hokkaido University in Japan have clarified a confusing, decade-long stagnation in summer warming across Greenland.
Their observational analysis and computer simulations exposed that changes in sea surface temperature in the tropical Pacific Ocean. Thousands of miles to the south, cause cooler summer temperatures throughout Greenland.
The outcomes, released in the journal Communications Earth & Environment, will help improve future predictions of the Greenland ice sheet and Arctic sea ice melting in the coming decades.
“The Greenland ice sheet is thawing in the long run due to global warming connected with greenhouse gas emissions. However, the pace of that melting has actually slowed down in the last years”.
States Hokkaido University environmental Earth scientist Shinji Matsumura. “That slowing was an enigma until our research study revealed it is connected to changes to the El Niño climate pattern in the Pacific.”
El Niño’s effect on Greenland
El Niño is a natural, cyclic sensation that increases the water temperature in the central and east-central equatorial Pacific Ocean. Scientists know that such large changes alter atmospheric conditions elsewhere due to their association with powerful waves of air pressure called teleconnections.
Climate experts battled to see just how the Pacific El Niño can cool Greenland in the summer. Since easterly summer winds in the tropics usually stop such teleconnections from developing.
In the brand-new research study, the team represented recent changes in the Pacific El Niño event. Pushing warmer sea temperatures even more north than typical. This took them past the influence of the easterly wind and enabled atmospheric teleconnections that extend up to Greenland to develop.
Consequently, these teleconnections disrupt the atmospheric conditions and thus the weather around Greenland in the summer. Especially, they drive more intense cyclones, which move cooler air over the land.
Satisfactory discoveries
The brand-new research study shows that this suffices to describe the region’s lower-than-expected temperatures and ice melting. Temperatures and rates of ice sheet melting both peaked in 2012.
“The findings, and the slowdown in Greenland’s summer warming, do not undermine the seriousness of climate change or the necessity to take on greenhouse gas emissions,” Matsumura stresses.
Instead, they demonstrate just how natural changes can act alongside the long-term global warming trend to varying local conditions. The downturn in warming is local to Greenland. The broader Arctic region stays one of the fastest-warming places on Earth.
El Niño events tend to precede similar yet different natural climatic changes called La Niña, in which sea surface temperatures decrease. These events often tend to bring higher temperatures to Greenland.
“We anticipate that global warming and ice sheet melting in Greenland and the rest of the Arctic will speed up even more in the future due to the effects of anthropogenic warming,” Matsumura claims.
Read the original article on Science Daily.
Read more: Arctic Winters Warming Origins Cold Damage in the Subtropics of East Asia.
