During the first week of April 2016 a significant surface warming event was observed over Baffin Bay (Figure 1). Mean surface temperatures over the area from the U.S. National Centers for Environmental Prediction (NCEP) Climate Forecast System Version 2 (CFSv2) Reanalysis ranged from -30 to -10º C on 1 April 2016 with anomalies of -10ºC in the south to +5ºC in the north. By 7 April 2016 the mean surface temperatures rose by 10 to 20º C with surface temperature anomalies of up to 20ºC off the west coast of Greenland.

The Suomi-NPP Visible Infrared Imaging Radiometer Suite (VIIRS) Ice Surface Temperature (IST) product (NOAA and the Cooperative Institute for Meteorological Satellite Studies (CIMSS), University of Wisconsin-Madison) observed the same warming event over the 1 to 6 April period (Figure 2). IST was in the range of -28 to -8ºC (245-265 K) on 1 April, warming to -18 to +2ºC (255-275 K) by 6 April. A strong ridge of high pressure developed over Greenland, allowing warm air from the south to be advected over the Baffin Bay region.

This early April warming in Baffin Bay led to record-smashing early surface melt on the Greenland Ice Sheet. “Scientists are ‘incredulous’ at abnormally high numbers for April, with melting across nearly 12% of ice sheet”, reports Climate Home. Almost 12% of Greenland’s ice sheet was melting on 11 April 2016, according to the Danish Meteorological Institute (DMI). This early melt beat the previous record for a melt of more than 10%, on 5 May 2010, by almost a month. “We had to check that our models were still working properly,” Peter Langen, climate scientist at DMI, told blog Polar Portal. Temperature measurements on the ice sheet confirmed the warming, exceeding 10ºC in some areas. Even a weather station at an elevation of 1,840 m recorded a maximum of 3.1ºC. Greenland’s usual melt season runs from early June to September. “Too much. Too early,” tweeted the World Meteorological Organization.