Warm air melts Greenland ice surface in 4 days
Washington, DC, United States (4E) – Warm air over Greenland melted 97 percent of the world’s largest island’s ice surface in just four days, according to NASA and university scientists who analyzed different satellite images of the Danish autonomous region.
Son Nghiem of NASA’s Jet Propulsion Laboratory in Pasadena, California said the extensive melting of Greenland’s ice surface occurred on July 12 based on the radar data from the Indian Space Research Organisation’s (ISRO) Oceansat-2 satellite that he analyzed last week.
At NASA’s Goddard Space Flight Center in Greenbelt, Maryland, Dorothy Hall, who studies the surface temperature of Greenland using the Moderate-resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra and Aqua satellites, confirmed Nghiem’s findings. The MODIS detected unusually high temperatures over Greenland on July 8 and extensive melting of its ice sheet surface by July 12.
The passive-microwave satellite data from the Special Sensor Microwave Imager/Sounder on a U.S. Air Force meteorological satellite also confirmed the melt seen by Oceansat-2 and MODIS, according to Thomas Mote, a climatologist at the University of Georgia in Athens, Geogria, and Marco Tedesco of City University of New York.
There was an unusually strong ridge of warm air or a heat dome over Greenland since end of May and this only started dissipating on July 16., Mote said.
A National Oceanic and Atmospheric Administration weather station at Summit Station in the center of the island measured air temperatures at above or within a degree of freezing for several hours on July 11-12.
The area around Summit Station, which is near the highest point of Greenland at 2 miles above sea level, also showed signs of melting, the first since 1889. Lora Koenig, a Goddard glaciologist and a member of the research team analyzing the satellite data on Greenland, said the melting event occurs once every 150 years as indicated by ice cores from the Summit.
Ice cover at high elevation quickly refreezes after melting while those near the coast are retained by the ice sheet. The rest goes to the ocean. Researchers have yet to determine if the ice melt will contribute to the rise in sea level and affect the overall volume of ice loss in Greenland this summer.