NARRATIVE FAILURE: one of the largest glaciers on earth shrinking again



[ad_1]

In a blow to global warming providers, a new study found that a huge Greenland glacier that was shrinking rapidly is expanding.

NBC News reports that a new study published in Nature Geoscience examined the Jakobshavn Glacier, in west-central Greenland, the fastest and largest glacier of ice cap volume, and revealed that unlike The situation in 2012, when the glacier was shrinking Each year, while lightening about 30 meters, the process was reversed.

The summary of the study indicates that the glacier "has been the largest source of mass loss in the Greenland Ice Sheet over the last 20 years. During this period, he retreated, accelerated and cleared up. "It links the growth and thickening of the glacier over the last two years to the" simultaneous cooling of the ocean waters of Disko Bay that spill over into the Ilulissat Icefjord, "adding," Ocean Temperatures in the upper 250 m of the bay have been brought back to levels never seen since the mid-1980s.

Scientists note that their information was collected in two sets of NASA data: the radar altimetry of the Oceans Melting Greenland mission and laser altimetry of the Icebridge operation. The study states, "Between 2016 and 2017, we observe an ice thickening of 20 to 30 m in the vicinity of the front … Repeated measurements of glacier and ice surface topography interferometer (GLISTIN ) in 2018 show that thickening has continued at a similar rate near but has now spread up to 80 km upstream and has spread laterally. "

The study acknowledges that "in recent years, ocean temperatures have cooled on the continental shelf near Jakobshavn Isbrae. We find that the ocean temperature in Disko Bay below about 150 m has been cooled by almost 2 degrees Centigrade between 2014 and 2016. "

Most importantly, the study states: "Jakobshavn Isbrae has witnessed rapid thinning episodes that have been going on for three decades since the early twentieth century. The most recent one started in 1997 and our observations on the recent slowdown and thickening could mark the end of this episode in 2017. Such episodic reversals underline the difficulty of forecasting contemporary trends to evaluate the contribution of glaciers to the rise in sea level. "

The lead author of the study, Ala Khazendar, NASA glaciologist in charge of the Oceans project Melting Greenland (OMG), said that the natural oscillation of the North Atlantic wavered between rise and fall. descent. He added that although the water can cool down, it will eventually warm up and the melting will increase.

Despite warnings from the study that forecasting the future is a difficult and nebulous pursuit, some scientists have still issued their warnings: Denmark's geologist and Greenland's ice and climate scientist, Jason Box, said, "It was a bit of a surprise. We sort of got used to an uncontrolled system. The good news is that it reminds us that everything is not happening as fast. But it is okay.

Ian Joughin, an ice science researcher at the University of Washington, said it would be "a serious mistake" to assume in the study that global warming was not real, adding that what the scientists discovered was "to a large extent, a temporary shock. Declining events are occurring on the stock market, but overall, the long-term trajectory is rising. It's really the same thing. "

[ad_2]
Source link