Intercomparison of firn core and meteorological data

High resolution firn core records of the oxygen isotope ratio (δ18O) and trace chemical species were extracted from a high accumulation site on Law Dome, East Antarctica. Inter-core comparisons were conducted and regional events identified in cores 5 km apart. High resolution dating of one of the firn cores was established using a co-located Automatic Weather Station (AWS) equipped with a snow accumulation sensor, allowing dating of individual precipitation events in the firn core record. Variations in the δ18O and trace chemical records were compared with meteorological conditions at the mesoscale and the synoptic-scale. Particular focus was given to an abrupt change in sea salt concentrations and δ18O within a depth range that appears from AWS accumulation data to have been deposited over a 24 hour period. The abrupt change in the firn core record was found to be consistent with an abrupt change in meteorological conditions. Direct comparisons between high resolution firn core records and meteorological conditions will greatly facilitate the interpretation of signals preserved in deep ice cores.