Influence of large-scale teleconnection patterns on methane sulfonate ice core records in Dronning Maud Land
Records of methane sulfonate (MS) in ice cores from the high plateau of DronningMaud Land (DML), Antarctica, drilled in the framework of the European Project for IceCoring in Antarctica, are investigated for their potential as an environmental andclimate archive for the Atlantic sector of the Southern Ocean. Despite postdepositionalchanges, years of extraordinary MS concentrations can be clearly detected in the icecore records. We use composite anomaly maps of atmospheric parameters from theNational Centers for Environmental Prediction/National Center for Atmospheric Researchreanalysis fields for years of extreme MS concentration to detect atmospheric patternscausing MS variability. Changing atmospheric transport is shown to be an important,but not exclusive, parameter being conserved in the MS record in DML. The oftenhypothesized direct link between high MS concentrations and El Nino events is notsupported for the observed region whereas the Antarctic Dipole (ADP), which ismodulated by El Nino Southern Oscillation conditions, exerts significant influence. Aclear 13.9-year cycle can be found throughout a 2000-year MS record that can be relatedto variations in the ADP. Over the last 300 years a 4.6-year cycle is revealed in theMS (and sea-salt record), which vanishes in the deeper part of the ice core as aconsequence of diffusion processes. From the long-term perspective, periods of high MSconcentrations are connected to, on average, higher sea-salt aerosol as well, reflecting aseasonally independent influence of transport on both species. A distinctive period ofefficient atmospheric transport, probably due to a pronounced ADP, could be foundfrom 1200 to 1600 A.D.