Exploring seasonal accumulation bias in a west central Greenland ice core with observed and reanalyzed data

Abstract

AbstractThe seasonality of accumulation in west central Greenland is investigated to determine whether a summer bias exists in a multi-century ice core recovered from Crawford Point (CP). Such a bias would negatively affect the ice core’s potential for reconstructing the history of winter circulation patterns including the North Atlantic Oscillation. An automatic weather station (AWS) installed at the CP site in 1995 records sub-daily surface heights and affords a unique opportunity to assess the seasonal distribution of accumulation and test the performance of five gridded reanalysis datasets and a regional climate model. Simulated accumulation compares remarkably well with in situ measurements from both the AWS and CP ice core, demonstrating their potential to accurately represent accumulation in this region. Seasonal accumulation exhibits no summer maximum, indicating that any concurrent precipitation maximum is likely offset by melt and/or sublimation effects. The lack of a strong seasonal accumulation bias implies that the CP ice core is well suited for future investigations of the history of winter circulation patterns.