Particulate and water‐soluble carbon measured in recent snow at Summit, Greenland

Water‐soluble organic carbon (WSOC), water‐insoluble particulate organic carbon (WIOC), and particulate elemental carbon (EC) were measured simultaneously for the first time on the Greenland Ice Sheet in surface snow and in a 3‐meter snow pit. Snow pit concentrations reveal that, on average, WSOC makes up the majority (89%) of carbonaceous species, followed by WIOC (10%) and EC (1%). The enhancement of OC relative to EC (ratio 99:1) in Greenland snow suggests that, along with atmospheric particulate matter, gaseous organics contribute to snow‐phase OC. Comparison of summer surface snow concentrations in 2006 with past summer snow pit layers (2002–2005) found a significant depletion in WSOC (20–82%) and WIOC (46–65%) relative to EC for 3 of the 4 years. The apparent substantial loss of WSOC and WIOC in aged snow suggests that post‐depositional processes, such as photochemical reactions, need to be considered in linking ice core records of organics to atmospheric concentrations.