Glacio-chemical study spanning the past 2 kyr on three ice cores from Dronning Maud Land, Antarctica - 1. Annually resolved accumulation rates

For the first time, annually resolved accumulation rates have been determin ed in central Antarctica by means of counting seasonal signals of ammonium, calcium, and sodium. All records, obtained from three intermediate depth i ce cores from Dronning Maud Land, East Antarctica, show rather constant acc umulation rates throughout the last 9 land a typical year-to-year centuries with mean values of 63, 61, and 44 mm H2O y(-1) variation of about 30%. Fo r the last few decades, no trend was detected accounting for the high natur al variability of all records. A significant weak intersite correlation is apparent only between two cores when the high-frequency part with periods l ess than 30 years is removed. By analyzing the records in the frequency dom ain, no persistent periods were found. This suggests that the snow accumula tion in this area is mainly influenced by local deposition patterns and may be additionally masked by redistribution of snow due to wind. By comparing accumulation rates over the last 2 millennia a distinct change in the laye r thickness in one of the three cores was found, which might be attributed either to an area upstream of the drilling site with lower accumulation rat es, or to deposition processes influenced by surface undulations. The missi ng of a clear correlation between the accumulation rate histories at the th ree locations is also important for the interpretation of small, short time variations of past precipitation records obtained from deep ice cores.