A positive trend in western Antarctic Peninsula precipitation over the last 50 years reflecting regional and Antarctic-wide atmospheric circulation changes
A positive trend in western Antarctic Peninsula precipitation over the last 50 years reflecting regional and Antarctic-wide atmospheric circulation changes
复制标题
过去50年南极半岛西部降水呈积极趋势，反映了区域和整个南极地区的大气环流变化
作者：
J. Turner;T. Lachlan;S. Colwell;G. Marshall
本文利用南极半岛西侧法拉第/Vernadsky站的降水日数（常规天气观测报告有雪或雨的日数）的现场观测资料和欧洲中期天气预报中心再分析（ERA-40）项目的40年场资料，研究了南极半岛周围的降水和大气环流变化。结果表明，降水日数是阿蒙森-别林斯高晋海平均海平面气压（MSLP）的一个很好的代用指标。自20世纪50年代初以来，该站的年总降水日数一直以12.4天的十年统计显著增长率增长，夏季和秋季的增长最大。这是一年中南方环形模态（SAM）经历最大转变为正相位的时候，南极沿海地区的MSLP值下降。环极槽的低气压导致法拉第/韦尔纳德斯基的上升速度加快，降水量增加。
Abstract In situ observations of precipitation days (days when snow or rain was reported in routine synoptic observations) from Faraday/Vernadsky station on the western side of the Antarctic Peninsula, and fields from the 40 year European Centre for Medium-Range Weather Forecasts re-analysis (ERA-40) project are used to investigate precipitation and atmospheric circulation changes around the Antarctic Peninsula. It is shown that the number of precipitation days is a good proxy for mean sea-level pressure (MSLP) over the Amundsen–Bellingshausen Sea. The annual total of precipitation days at the station has been increasing at a statistically significant rate of +12.4 days decade–1 since the early 1950s, with the greatest increase taking place during the summer and autumn. This is the time of year when the Southern Annular Mode (SAM) has experienced its greatest shift to a positive phase, with MSLP values decreasing in the Antarctic coastal zone. The lower pressures in the circumpolar trough have resulted in greater ascent and increased precipitation at Faraday/Vernadsky.