Research from the University of Sheffield has shown that
unusual changes in atmospheric jet stream circulation caused the exceptional
surface melt of the Greenland Ice Sheet (GrIS) in summer 2012.
An international team led by Professor Edward Hanna from the
University of Sheffield’s Department of Geography used a computer model
simulation (called SnowModel) and satellite data to confirm a record surface
melting of the GrIS for at least the last 50 years - when on 11 July 2012, more
than 90 percent of the ice-sheet surface melted. This far exceeded the previous
surface melt extent record of 52 percent in 2010.