东南极中山站-昆仑站断面最高和最低气温变化特征

利用中山站-昆仑站断面自动气象站2 m气温和同期再分析资料分析了南极沿海到内陆高原的最高和最低气温的变化特征, 并通过个例讨论了气温出现极端过程的天气背景. 结果表明: 南极中山站-昆仑站断面最高和最低气温季节变化趋势基本相似, 年际变化不明显. 最高气温标准偏差大于最低气温, 冬季气温标准偏差明显大于夏季, 且夏季气温变化幅度远小于冬季. 随海拔的增加, 最高气温年较差逐渐增大, 最低气温年变化的无芯率(气温没有明显的最小值程度)呈增大趋势, 夏季气温变化幅度逐渐增大, 冬季气温变化幅度的区域性差异不明显; 2005年7月25-31日的极端降温过程主要受到极涡、地面冷高压及下降风的共同影响.

Variation of the maximum and minimum air temperatures along the traverse route from Zhongshan to Kunlun Station,East Antarctica

Based on the hourly 2-m air temperature records from Zhongshan Station, LGB69, EAGLE and Dome A, East Antarctica, and the ERA Interim reanalysis data of the same period, the maximum and minimum air temperature change characteristics from the Antarctic coast to the inland plateau were analyzed, and the extreme temperatures occurring weather background were discussed through a case study. Results show that the monthly maximum/minimum temperature variations at the four stations have a more consistent trend for seasonal variability but not for interannual variability. The standard deviation is significantly larger for maximum temperature rather than that for the minimum one, and in winter rather than that in summer. Moreover, the range of temperature change in summer is far less than that in winter. Annual difference of maximum temperatures increases with altitude, the rate corelessness (the degree of temperature has not significant minimum) of minimum temperature increases with altitude too; the changing range of summer temperature increases with altitude, but the spatial variation of the changing range of winter temperature is not obvious. An extreme cooling process at Zhongshan Station during 25 to 31 July, 2005, was closely connected with the polar vortex, together with cold high pressure system and the katabatic wind in Antarctica continent.