黄山连续性云海过程的天气学分析

Synoptic Analysis of a Continuous Cloud Deck Event in Huangshan Mountain

用美国NCEP/NCAR的全球日平均分析场资料,分析了黄山1 984年1月1 9～2 4日连续6天云海天气过程的大气环流和物理量时间演变特征。结果表明,50 0hPa平均高度场鄂霍次克海为阻高,乌拉尔山以东为高压脊,我国东北存在一低压,黄山受偏西气流影响;1 0 0 0hPa平均高度场黄山处在南伸的高压底部,受NE气流影响。物理量时间演变图上,1 8～1 9日降温、降湿,垂直速度由上升气流转变为弱下沉气流;云海出现阶段,气温、比湿、垂直速度稳定少变,风速较小,风向较乱。

Based on the NCEP/NCAR reanalysis data, the features of atmospheric circulation and meteorological factors of the 6-day continuous cloud deck appeared on January 19 to 24, 1984 in Huangshan mountain are analyzed, It shows that the event occurred under the conditions as follow. At 500hPa level, a blocking high laid in Okhotsk, the pressure ridge in Wulaershan leant towards east, a depression laid over Northeast China, and westerly flow over the Huangshan mountain. At 1000hPa, a northeasterly forward high is over the Huangshan Mountain. The cloud deck appeared after cold front and heavy rain, and then temperature and humidity droped, and the upward current turned into downward motion. During the appearance of cloud deck, the temperature, the specific humidity, and the vertical velocity are changing less, and the wind velocity is lower, but the wind direction is chaos.