Abstract

The paper presents the results of the verification of ERA-Interim and ERA5 reanalyses data on surface air temperature obtained from drifting buoys, ground-based weather stations, and, for the first time, from measurements at the North Pole drifting stations. The North Pole station data were not assimilated in the reanalyses, which provides a rare opportunity for independent validation. The comparison with data of the North Pole drifting stations revealed that bias for the cold season in the Arctic basin is 2.25°С for ERA-Interim and 3.92°С for ERA5, respectively. The comparison with data of drifting buoys allows us to speculate about the cause of such large errors in the reanalyses. Some buoys were installed from the air-based platform. In this case, the temperature sensor of the buoy was potentially buried in the snow cover that shielded it from the cold atmosphere and contributed to the heating due to the heat flux from the underlying layer of sea water. The assimilation of such data could be one of the reasons for the overestimation of air temperature over drifting ice in the both reanalysis.

中文翻译：

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ERA-Interim验证和ERA5重新分析了北极地表温度的数据

摘要

本文介绍了ERA-Interim的验证结果，并且ERA5重新分析了从漂流浮标，地面气象站以及首次从北极漂流站的测量获得的地表空气温度数据。重新分析中没有吸收北极站的数据，这为独立验证提供了难得的机会。与北极漂流站数据的比较表明，北极盆地冷季的偏差为ERA-Interim为2.25°С，ERA5为3.92°С。通过与浮标数据的比较，我们可以推测重新分析中如此大的误差的原因。从空中平台安装了一些浮标。在这种情况下，浮标的温度传感器可能埋在积雪中，从而使它免受冷空气的影响，并由于来自底层海水的热通量而对热量产生了贡献。在两次再分析中，这些数据的同化可能是高估了浮冰上空气温度的原因之一。