early September Greenland ice reflectivity remains low, some melting remains active

While ice sheet average temperatures are declining with the return of the cold season this September, ice sheet reflectivity (a.k.a. albedo) remains anomalously low (Fig. 1). The low albedo values reflect (pun alert) where snow accumulation has not yet covered the darkened surface. There remain some areas where melting remains active at the lowest elevations of the ice sheet (Fig. 2). Melt promotes or maintains low ice reflectivity.  Available sunlight in 2012 thus continues to heat the ice and snowpack more than it has in the period of observations beginning in 2000. Less heat will be required to maintain melting or bring the ice to the melting point in the future. It is easy to predict early melt onset in 2013 and a continuation of increasing ice sheet melt rates that contribute to the recently observed net ice loss from Greenland.

Fig. 1. Surface solar reflectivity retrieval from the NASA MODIS sensor on the Terra satellite

Fig. 2. Land surface temperature retrieval from the NASA MODIS sensor on the Terra satellite.

For more information about these analyses see http://bprc.osu.edu/wiki/Greenland_Ice_Albedo_Monitoring and http://bprc.osu.edu/wiki/Greenland_Ice_Surface_Temperature_Monitoring