By Gary Thomas
Researchers from the GFZ German Research Centre for Geosciences have discovered that the mass loss through iceberg calving, melting and fluctuations in rainfall is highest in southwest and northwest Greenland. There is a continuous mass loss in the Greenland ice sheet and thus, it contributes at approximately 0.7 mm per year to the presently observed sea level change of around 3 mm per year. This trend rises every year by an additional 0.07 mm.
The researchers have made a new comparison of three types of satellite observations: evaluation of the variation between the glacier discharge and the gathering of regional atmospheric models, height difference with the laser altimeter measured on the NASA satellite ICESat, and measurements of the variation in gravity using the satellite pair GRACE.
The researchers can now determine which percentage of iceberg calving, melting and rainfall fluctuations have on the mass loss with exceptional accuracy. Ingo Sasgen, a researcher at GFZ and head of the study, noted that the mass loss increase in the northwest region after 2005 is partially due to heavy snowfall in the previous years. There was a mass loss increase even in eastern Greenland in 2008 and 2009. The research reveals that for all studied areas, the calving and meting periods from 2002 to 2011 are extremely high compared to the past five decades.
The GFZ research work is based on the Helmholtz Association’s Helmholtz Climate Initiative called REKLIM and ice2sea, the EU project. The work helps the scientists to get a better understanding on the recent improvements of the Greenland ice sheet.