Sunday, 22 January 2012
A New Ice Core-Derived Melt History From West Central Greenland: Comparison with Contemporaneous Meteorological Observations and Passive Microwave-Derived Regional Melt Extent
Hall E (New Orleans Convention Center )
A melt history has been reconstructed from an ice core collected in 2007 at Crawford Point, Greenland (69.85°N; 47.12°W) at ~2000 m elevation in west central Greenland. This site lies in the zone that experiences intermittent summer melt and percolation. At this time melt features may form, thus providing a record of surface warmth. Melt features are primarily bubble fee and thus appear clearer and brighter than the surrounding snow, firn, or ice. The Crawford Point core was photographed and high-resolution digital images were used to quantify the extent of melt in each year using the time scale previously constructed by counting seasonal variations in dust, δ18O, nitrate and sulfate. This paper presents an efficient and relatively inexpensive technique for quantifying the annual melt percent from an ice core. The Crawford Point melt extent record is compared with the surface melt-area time series (1979-2006) derived from satellite-borne passive microwave observations and meteorological observations from a nearby automatic weather station.