Characteristics of Surface Meteorology at Lindsey Islands, Amundsen Sea, West Antarctica

Investigating warming in West Antarctica is important to understand and predict mass balance changes of the ice sheet. However, clear understanding of the extent and rate of warming across West Antarctica has been limited by the lack of ground-based meteorological measurements. An automatic weather station was set up at Lindsey Islands, the Amundsen Sea of West Antarctica, in 2008, and operated for about 7 years. The measured variables showed high interannual variability, particularly in winter seasons. The longitudinal shift of the center of the Amundsen Sea Low contributed to the large variability and resulted in much lower temperatures at the site, especially in winter seasons, through cold advection from the south. The measured data showed good agreement with ERA-Interim and ERA5 reanalysis data, though there was a large negative bias in wind speed. The ERA-Interim reanalysis data showed no significant trends in seasonal averaged temperature from 1980 to 2014, but significant trends were shown in pressure and wind speed in autumn (p < 0.05), even though the interpretation of the trend requires caution. The seasonal correlation coefficients of monthly averaged temperature (T) and pressure (P) between the study site and three neighboring automatic weather station sites in the coastal area were >0.8 for T and >0.92 for P and up to 0.76 for P and 0.72 for T at an inland site.