Multiyear accumulation and temperature history near the North Greenland Ice Core Project site, north central Greenland

Abstract

This paper presents a comparison of two independent methods of estimating subseasonal accumulation across the interior of Greenland. These methods, high‐resolution snow pit studies and atmospheric modeling, have differing spatial and temporal resolution, but both can estimate net accumulation for subseasonal and shorter periods. The snow pit approach is based on a documented relationship between high‐resolution snow pit profiles of oxygen stable isotope ratio (δ18O) and multiyear Special Sensor Microwave/Imager (SSM/I) 37‐GHz brightness temperature records. Comparison of SSM/I data to profiles obtained during the 1995 Alfred Wegener Institut North Greenland Traverse field season shows that δ18O data from snow in north central Greenland are a reliable, high‐resolution temperature proxy. This enables determination of accumulation amount, rate, and timing from approximately July 1991 through June 1995 across this 220‐km‐long transect of the ice sheet. Precipitation estimates derived from early modeling based on European Centre for Medium‐Range Weather Forecasts data show a similar average seasonal pattern but a diminished magnitude of accumulation (∼56%) for these sites. The slope of the multiyear T versus δ correlation was evaluated for each site on the basis of the observed and calculated temperature history from the nearby North Greenland Ice core Project (NGRIP) site automatic weather station. These data should assist interpretation of the paleoclimatic record in the NGRIP deep core.