A climatological analysis of high-precipitation events in Dronning Maud Land, Antarctica, and associated large-scale atmospheric conditions

• Main Authors: Welker, Christoph, Martius, Olivia, Froidevaux, Paul, Reijmer, Carleen H., Fischer, Hubertus
• Other Authors: Sub Dynamics Meteorology, Marine and Atmospheric Research
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2014
• Subjects: AMPS; ERA-Interim; High precipitation in Dronning Maud Land; Antarctica; Large-scale atmospheric conditions; Objective cyclone and blocking detection; Snow accumulation measurements from AWS; Atmospheric Science; Geophysics; Earth and Planetary Sciences (miscellaneous); Space and Planetary Science; Antarctic; Dronning Maud Land; Halvfarryggen; Kohnen; Kohnen Station; Pacific; The Antarctic; Weddell; Weddell Sea; Antarc*; DML
• Online Access: https://dspace.library.uu.nl/handle/1874/308260

The link between high precipitation in Dronning Maud Land (DML), Antarctica, and the large-scale atmospheric circulation is investigated using ERA-Interim data for 1979-2009. High-precipitation events are analyzed at Halvfarryggen situated in the coastal region of DML and at Kohnen Station located in its interior. This study further includes a comprehensive comparison of high precipitation in ERA-Interim with precipitation data from the Antarctic Mesoscale Prediction System (AMPS) and snow accumulation measurements from automatic weather stations (AWSs), with the limitations of such a comparison being discussed. The ERA-Interim and AMPS precipitation data agree very well. However, the correspondence between high precipitation in ERA-Interim and high snow accumulation at the AWSs is relatively weak. High-precipitation events at both Halvfarryggen and Kohnen are typically associated with amplified upper level waves. This large-scale atmospheric flow pattern is preceded by the downstream development of a Rossby wave train from the eastern South Pacific several days before the precipitation event. At the surface, a cyclone located over the Weddell Sea is the main synoptic ingredient for high precipitation both at Halvfarryggen and at Kohnen. A blocking anticyclone downstream is not a requirement for high precipitation per se, but a larger share of blocking occurrences during the highest-precipitation days in DML suggests that these blocks strengthen the vertically integrated water vapor transport (IVT) into DML. A strong link between high precipitation and the IVT perpendicular to the local orography suggests that IVT could be used as a "proxy" for high precipitation, in particular over DML's interior.