Initial in situ measurements of perennial meltwater storage in the Greenland firn aquifer

A perennial storage of water in a firn aquifer was discovered in southeast Greenland in 2011. We present the first in situ measurements of the aquifer, including densities and temperatures. Water was present at depths between similar to 12 and 37m and amounted to 18.70.9kg in the extracted core. The water filled the firn to capacity at similar to 35m. Measurements show the aquifer temperature remained at the melting point, representing a large heat reservoir within the firn. Using model results of liquid water extent and aquifer surface depth from radar measurements, we extend our in situ measurements to the Greenland ice sheet. The estimated water volume is 14020 Gt, representing similar to 0.4mm of sea level rise (SLR). It is unknown if the aquifer temporary buffers SLR or contributes to SLR through drainage and/or ice dynamics.