Properties of the Arctic 2-Meter Air Temperature Field for 1979 to the Present Derived from a New Gridded Dataset

Abstract

This paper discusses the behavior of the Arctic Ocean surface air temperature field for 1979?93. Temperatures are derived from a new gridded 6-h, 2-m air temperature dataset called POLES. These gridded air temperatures are estimated from optimal interpolation of temperature inputs from drifting buoys, manned Soviet North Pole (NP) drifting ice stations, coastal land weather stations, and ship reports. In processing the POLES data, the winter and summer properties of the mean NP temperatures are used to discard inaccurate or snow-covered buoys and to remove a summer warm bias. Comparison of the POLES and specific NP temperatures shows that the POLES temperature behaves well and gives better results than other gridded temperature datasets. Maps of the mean seasonal temperatures give realistic results consistent with other published estimates, and plots of the summer advance and retreat of the 0°C isotherm show the expected asymmetry between advance and retreat associated with the open water formation adjacent to the coasts. Also, comparison of the regional POLES observations of the annual onset of melt and freeze with published estimates derived from visible and passive microwave satellite data gives realistic results. However, problems with the dataset arise in the post-1991 period from the termination of the NP stations and a reduction in the number of Siberian and Alaskan weather stations. In spite of these problems, the paper shows that the POLES dataset provides an improved air temperature field for use in numerical sea ice models and for comparison with satellite datasets.