Rare Arctic hurricane suppresses the melting of Greenland’s history

Once a raging tropical cyclone, the remnants of Hurricane Larry have turned into a howling winter storm.

After hitting the coast of Newfoundland last week and then crossing the North Atlantic eastward, Larry has swept across the southeast coast of Greenland in the past few days-a rare feat for a former Atlantic hurricane.

The storm dumped heavy snow and blew strong winds as it passed through the Arctic islands. The Danish Institute of Meteorology reports that wind gusts at some weather stations exceed 90 miles per hour.

The Danish research institute estimates that Greenland added nearly 10 billion tons of additional ice and snow in one day on Sunday. It is expected that more snow will be accumulated yesterday and today.

Larry remained in hurricane conditions until Newfoundland, and then turned into a post-tropical cyclone when turning to Greenland. Post-tropical cyclones have different characteristics from hurricanes. They usually form cold cores rather than the warm centers that are common in tropical cyclones, but they can still produce hurricane-level winds.

For Atlantic hurricanes, this is an unusual trajectory, but not unheard of. The last storm to land in Newfoundland in the form of a real hurricane was Maria in 2011, just one year after Hurricane Igor hit the island in 2010.

Tropical storms hit Greenland even more rarely. The last time was Hurricane Noel in 2007, which transformed into a post-tropical system as it drifted across New England and eastern Canada, eventually hitting southwestern Greenland, and then eastward across the Atlantic Ocean.

It is not clear whether the Atlantic hurricane will move north over time. In other parts of the world, studies have shown that climate change is causing tropical cyclones to migrate to the polar regions. This means that coastal communities that were rarely threatened by hurricanes in the past may face greater risks in the future.

In the Atlantic, the data is not clear. Nonetheless, experts warn that warmer waters help hurricanes become stronger-they may increase the likelihood that rare northern storms will last longer.Climate line, August 23).

Larry’s unusual footprint is the latest wonder of the eventful summer of the Greenland Ice Sheet.

According to data from the National Ice and Snow Data Center, the melting rate at the beginning of the season was lower than average, while the increase in snow and ice was higher than average. However, in July, the situation changed. The above-average temperature, combined with the low pressure system that helped push the warm air in southern Greenland, led to two back-to-back melting of the ice sheet in the second half of July.

Scientists estimate that in one day on July 28, 12.5 billion tons of ice melted and was lost from the ice sheet. This is the third largest single-day melting event on record, second only to similar events in 2019 and 2012.

In mid-August, another strong melting incident hit the ice sheet. According to NSIDC, there has never been such a big melting day this season.

Then, on August 14, scientists reported a shocking event at the National Science Foundation summit station, a research outpost located near the highest point of the Greenland ice sheet: it was raining.

This is the first time in recorded history that rainfall has been observed on the top of a mountain about 2 miles above sea level, where the temperature rarely rises above freezing.

After the melting event in mid-August, satellite images and aviation research flights showed that deep blue melting pools were widely scattered on the white surface of the ice sheet.

“On the way to Konkruzwak, we flew over [a] A group of huge melting pools and rivers that are beginning to freeze again,” Tweet NASA scientist Josh Willis, shortly after the melting event. “Our captain Jim Haffey has been flying over the ice sheet for 25 years, and he said the ice sheet has melted more than he has ever seen.”

The largest melting years on record in Greenland were 2019 and 2012. The melting rate was the highest in 2012. However, the total ice loss in 2019 was higher, possibly because of the unusually low snowfall that year. Scientists estimate that the ice sheet lost approximately 532 billion tons of ice in 2019.

Scientists predict that as the Arctic climate continues to warm, intense melting events on the Greenland ice sheet will become more common. This is a concern of coastal communities all over the world. As ice melts and flows into the ocean, it will raise global sea levels.

The snowfall from Larry, although unusual, is a welcome addition to the mass balance of the Greenland ice sheet after such a strong melting earlier this summer.

“This is great news for ice sheets that are not expected to significantly melt or rain,” Tweet Xavier Fettweis, a climate scientist at the University of Liege, when the storm approached Greenland last weekend. “Only snow!”