南极罗斯海恩克斯堡岛短期气候特征分析

南极罗斯海恩克斯堡岛(Inexpressible Island)是中国南极新建考察站重点预选区域。本文利用1988—2012年曼努埃拉自动气象站(AWS Manuela)资料统计分析了该岛的气温、相对湿度、气压和风速风向等要素的特征和变化趋势。结果表明,该岛多年平均气温为-18.5℃,年平均气温有降低趋势;多年平均相对湿度较低,仅为45%,但春夏秋冬各季节的平均湿度均有增加趋势;多年平均气压为979.7hPa,无显著变化趋势;该站点多年平均风速为12.0 m·s-1,风向以WNW为主。干冷的下降风为该岛风场的主要特征,强下降风事件多发生在冬季(49.8%),其风速在25—45 m·s-1之间,冬季单次强下降风事件的平均持续时间达10 h以上。和中山站相比,该站点气温更低、空气更干燥、风速更大,这对该岛的越冬考察活动将带来巨大挑战。

ANALYSIS OF SHORT-TERM CLIMATOLOGY AT INEXPRESSIBLE ISLAND,ROSS SEA,ANTARCTICA

Inexpressible Island in the Ross Sea, Antarctica, has been proposed as a site for a new Antarctic station for China. Here we present an analysis of temperature, humidity, pressure, wind speed and wind direction records of AWS Manuela at Inexpressible Island. Multi-year averaged temperature is −18.5°C, with a significant warming trend during summer. Multi-year averaged humidity is 45%, with significant increasing trends apparent in all seasons. Multi-year averaged pressure is 979.7hPa, though no significant trend is apparent. Multi-year averaged wind speed is 12.0m/s and dominant wind direction is WNW. The cold and dry katabatic wind is the dominant feature in this area, with most katabatic events occurring in winter (49.8%). During the typical winter katabatic event, wind speed varied between 25 and 45m/s and mean duration exceeded more than 10 hours. Compared with Zhongshan Station, the temperature and humidity at Inexpressible Island are lower, and wind speeds greater, posing considerable challenges to scientific activities there especially in winter.