Abstract

The glaciers within the Amundsen Sea Embayment (ASE), West Antarctica, are amongst the most rapidly retreating in Antarctica. Meteorological reanalysis products are widely used to help understand and simulate the processes causing this retreat. Examples of their uses in this region are: to force ocean and atmospheric models, to examine long term meteorological variability in the region and as a comparison to satellite observations of surface accumulation on glaciers. While their use is commonplace, very little is known about the performance of the reanalysis products in a region with very sparse coverage of in-situ observations. Here we provide an evaluation against observations of four of the latest global reanalysis products within the ASE region – the ECMWF Interim Re-analysis (ERA-I), Japanese 55-year Reanalysis (JRA-55), Climate Forecast System Reanalysis (CFSR) and Modern Era Retrospective-Analysis for Research and Applications (MERRA). The observations comprise data from four automatic weather stations (AWS), three research-vessel cruises and a new set of 38 radiosondes all within the period 2009-2014. The focus here is on near surface temperature, humidity and wind speed, we make use of the year-round AWS observations to evaluate the seasonal variability of temperature biases in the reanalysis products. The radiosonde observations allow discussion of how the reanalysis products represent common features such as temperature inversions and low level jets.