Effects of seasonal variability of accumulation on yearly mean δ18O values in Antarctic snow

The annual mean oxygen-isotope content of Antarctic snow is strongly influenced by the seasonal variability of accumulation. Since the annual mean delta(18)O value is frequently used to derive mean annual temperatures from ice cores, changes in atmospheric circulation pattern can lead to large errors in the deduced temperature record. At the German Antarctic wintering base, Neumayer, accumulation measurements have been carried out continuously over the last 16 years. Weekly readings of accumulation stakes combined with snow pits and shallow firn cores are used to investigate the influence of the seasonal, variability of accumulation on the annual mean delta(18)O values and to estimate the possible error in the determination of annual mean temperatures from ice cores by using the oxygen-isotope record.