利用常规观测资料、雷达回波资料、TBB卫星资料,WRF模式模拟输出的高时空分辨率结果对发生在2012年7月29-30日("7·29")宁夏北部地区的一次大暴雨过程的维持和演变进行详细分析。主要结论如下:(1)此次大暴雨过程与200 h P...利用常规观测资料、雷达回波资料、TBB卫星资料,WRF模式模拟输出的高时空分辨率结果对发生在2012年7月29-30日("7·29")宁夏北部地区的一次大暴雨过程的维持和演变进行详细分析。主要结论如下:(1)此次大暴雨过程与200 h Pa高空急流、500 h Pa短波槽及700 h Pa切变线发展和变化密切相关。(2)模式结果显示700 h Pa低涡及暖式切变线、低空急流形成是大暴雨形成的主要原因之一;低空急流从29日22:00形成,维持近7 h。(3)分析发现高层辐散明显早于低层的空气辐合,在低层空气辐合中心出现之后高空辐散继续加强,高空强辐散和低空强辐合导致明显的上升及700 h Pa低空急流形成和发展。(4)诊断分析显示ΔNBE的范围与1 h后强降水的落区有很好的对应关系,对流性降水阶段ΔNBE较大,不平衡特征明显,而在稳定性降水阶段大气质量场和流场之间的不平衡特征相对较小。(5)对此次暴雨的水汽输送分析表明水汽主要由偏南风低空急流输送,净水汽输送强度的变化与对流性降水阶段和稳定性降水阶段较为吻合。展开更多
The real-time data of the high level atmosphere obtained by the R/V Xiangyanghong No. 5 involved in the international TOGA-COARE project at 2°S, 155°E and at fixed real time of 05, 11, 19 and 23 h GMT each d...The real-time data of the high level atmosphere obtained by the R/V Xiangyanghong No. 5 involved in the international TOGA-COARE project at 2°S, 155°E and at fixed real time of 05, 11, 19 and 23 h GMT each day from Nov. 5, 1992 to Feb. 18, 1993 are used to analyze diagnostically the vertical structure of wind and humidity over the central area of the warm pool. The results show that (1) the lowfrequency oscillation of the equatorial westerlies (i. e. reconstruction-development --decline) is closely related to the vigour and interruption of the Asian-Australian monsoon (including air flow across the equator caused by East Asia cold wave), (2) the variabilities of the vertical structure of wind and humidity, and the processes of precipitation and gale weather in the troposphere of the warm pool area are closely related to the intensity of the equatorial westerlies, and (3) there are strong wind belts over the high and low level atmosphere in the western equatorial Pacific at the inception of the ENSO event, and jet flow at the high and low level atmosphere during the equatorial westerly burst.展开更多
文摘利用常规观测资料、雷达回波资料、TBB卫星资料,WRF模式模拟输出的高时空分辨率结果对发生在2012年7月29-30日("7·29")宁夏北部地区的一次大暴雨过程的维持和演变进行详细分析。主要结论如下:(1)此次大暴雨过程与200 h Pa高空急流、500 h Pa短波槽及700 h Pa切变线发展和变化密切相关。(2)模式结果显示700 h Pa低涡及暖式切变线、低空急流形成是大暴雨形成的主要原因之一;低空急流从29日22:00形成,维持近7 h。(3)分析发现高层辐散明显早于低层的空气辐合,在低层空气辐合中心出现之后高空辐散继续加强,高空强辐散和低空强辐合导致明显的上升及700 h Pa低空急流形成和发展。(4)诊断分析显示ΔNBE的范围与1 h后强降水的落区有很好的对应关系,对流性降水阶段ΔNBE较大,不平衡特征明显,而在稳定性降水阶段大气质量场和流场之间的不平衡特征相对较小。(5)对此次暴雨的水汽输送分析表明水汽主要由偏南风低空急流输送,净水汽输送强度的变化与对流性降水阶段和稳定性降水阶段较为吻合。
文摘The real-time data of the high level atmosphere obtained by the R/V Xiangyanghong No. 5 involved in the international TOGA-COARE project at 2°S, 155°E and at fixed real time of 05, 11, 19 and 23 h GMT each day from Nov. 5, 1992 to Feb. 18, 1993 are used to analyze diagnostically the vertical structure of wind and humidity over the central area of the warm pool. The results show that (1) the lowfrequency oscillation of the equatorial westerlies (i. e. reconstruction-development --decline) is closely related to the vigour and interruption of the Asian-Australian monsoon (including air flow across the equator caused by East Asia cold wave), (2) the variabilities of the vertical structure of wind and humidity, and the processes of precipitation and gale weather in the troposphere of the warm pool area are closely related to the intensity of the equatorial westerlies, and (3) there are strong wind belts over the high and low level atmosphere in the western equatorial Pacific at the inception of the ENSO event, and jet flow at the high and low level atmosphere during the equatorial westerly burst.
