[Arctic] Greenland ice sheet [in “State of the Climate in 2012”]

• Main Authors: Tedesco, Marco, Alexander, P., Box, J. E., Cappelen, J., Knudson, N. T., Mote, T., Steffen, K., van de Wal, R. S. W., Wahr, J., Wouters, B.
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Meteorological Society 2013
• Subjects: Hydrology; Meltwater; Geomorphology; Climatic changes; Mineralogy; Geology; Arctic; Greenland; Ice Sheet
• Online Access: https://doi.org/10.7916/D8BK1C72

Melting at the surface of the Greenland Ice Sheet set new records for extent and melt index (i.e., the number of days on which melting occurred multiplied by the area where melting was detected) for the period 1979–2012, according to passive microwave observations (e.g., Tedesco 2007, 2009; Mote and Anderson 1995). Melt extent reached ~97% of the ice sheet surface during a rare, ice-sheet-wide event on 11–12 July (Fig. 5.13a; Nghiem et al. 2012). This was almost four times greater than the average melt extent for 1981–2010. The 2012 standardized melting index (SMI, defined as the melting index minus its average and divided by its standard deviation) was +2.4, almost twice the previous record of about +1.3 set in 2010.