ISRO data shows 'extraordinary' melt of Greenland ice sheet

A massive ice sheet in Greenland has melted this month over an unusually large area, which was detected after analysing radar data from the Indian Space Research Organization's ( ISRO) Oceansat-2 satellite. The 'unprecedented' melting is highest in three decades of satellite observation, Nasa said.Melting even occurred at Greenland's coldest and highest place, Summit station. The thawed ice area jumped from 40% of the ice sheet to 97% in just four days from 8 to 12 July. Although about half of Greenland's ice sheet normally melts over the summer months, the speed and scale of this year's melting surprised scientists, who described the phenomenon as "extraordinary".Son Nghiem of Nasa's Jet Propulsion Laboratory in Pasadena, California, was analysing radar data from the ISRO's Oceansat-2 satellite last week when he noticed that most of Greenland appeared to have undergone surface melting on 12 July. "This was so extraordinary that at first I questioned the result: was this real or was it due to a data error?" Nghiem said.[caption id="attachment_3990" align="alignleft" width="380"]

Reuters[/caption]Nasa said that nearly the entire ice cover of Greenland, from its thin, low-lying coastal edges to its centre, which is 3 km thick, experienced some degree of melting at its surface. "Satellite observations are helping us understand how events like these may relate to one another as well as to the broader climate system," said Tom Wagner, Nasa's cryosphere programme manager in Washington.He said that, because this Greenland-wide melting has happened before, Nasa is not yet able to determine if this is a natural but rare event, or if it has been sparked by manmade global warming.Scientists believe much of Greenland's ice was already freezing again. Until now, the most extensive melting seen by satellites in the past three decades was about 55% of the area. Ice last melted at Summit station in 1889.The news comes days after Nasa satellite imagery revealed that a massive iceberg, twice the size of Manhattan, had broken off a glacier in Greenland.PTI