The impact of the northward jump and westward movement of the East Asian westerly jet core fi：om the westem Pacific Ocean to the Qinghai-Tibet Plateau on precipitation distribution of eastem China is studied. It is c...The impact of the northward jump and westward movement of the East Asian westerly jet core fi：om the westem Pacific Ocean to the Qinghai-Tibet Plateau on precipitation distribution of eastem China is studied. It is concluded that on the one hand, the northward jump of the jet causes the precipitation belt to move northward from the middle and lower reaches of the Yangtze River valley and withdraw during the Mei-yu season; on the other hand, the westward movement of the jet core has no correspondence with withdrawal of the Mei-yu season. However, the earlier or later occurrence of the westward movement of the jet has an influence on the process of the rain belt moving northward than the northward jump of the jet： the rain belt moves northward from the middle-lower Yangtze River valley to the Huaihe River and then to an area between the Yellow River and Huaihe River during years when the time of the westward movement of the jet core is later than that of the northward jump of the jet and from the middle-lower Yangtze River valley to an area between the Yellow River and Huaihe River in other years. Further analysis shows that： （1） The northward jump of the jet and the westward movement of the East Asian westerly jet core causes significant variation of the general atmospheric circulation in middle latitudes and water vapor transport from the western Pacific, but not from the Bay of Bengal. （2） Impact of the northward jump and the westward movement of the East Asian westerly jet core on circulation are different, therefore, water vapor transport from the western Pacific and its impact on the rain belt are different. The earlier or later occurrence of the westward movement of the jet core than the northward jump of the jet causes the process of circulation and water vapor transport to be different which produces a different process of the rain belt moving northward.展开更多
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
By using the data which included the conventional weather chart,the satellite cloud image,the regional automatic meteorological station and the new generation of weather radar,the regional strong precipitation process...By using the data which included the conventional weather chart,the satellite cloud image,the regional automatic meteorological station and the new generation of weather radar,the regional strong precipitation process which happened in Shandong Province during July 8-9 in 2009 was analyzed comprehensively.The results showed that Shandong Province was in the strong convergence zone of atmospheric vorticity in the low layer and the ascent zone of vertical velocity.The shear line was generated in the eastward process of northwest vortex,and the ground inverted trough extended to Shandong,which provided the dynamic condition for the formation of rainstorm.The coupling of jet stream in the high-low altitude enhanced the development of convection.The low-altitude jet stream was the main water vapor transportation channel,which provided the water vapor condition for the generation of rainstorm.The water vapor was mainly from the South China Sea and the Bay of Bengal.展开更多
From June 18th to June 19th of 2009,Heilongjiang Province was hit by the regional rainstorm rarely paralleled in history.According to the findings based upon the conventional observation data,the precipitation occurre...From June 18th to June 19th of 2009,Heilongjiang Province was hit by the regional rainstorm rarely paralleled in history.According to the findings based upon the conventional observation data,the precipitation occurred under the double-blocking situation of Ural Mountains and the Sea of Okhotsk.The main influencing systems were the upper vortex and northward low-pressure that came from Hetao area,accompanied by the delivery of high and low level jet stream.The results showed that the evolvement of blocking high,transfer of water vapor and configuration of high and low level jet stream were the key factors resulting in the rainfall process.展开更多
基金supported by the National Natural Science Foundation of China (Grant No.40675041)
文摘The impact of the northward jump and westward movement of the East Asian westerly jet core fi：om the westem Pacific Ocean to the Qinghai-Tibet Plateau on precipitation distribution of eastem China is studied. It is concluded that on the one hand, the northward jump of the jet causes the precipitation belt to move northward from the middle and lower reaches of the Yangtze River valley and withdraw during the Mei-yu season; on the other hand, the westward movement of the jet core has no correspondence with withdrawal of the Mei-yu season. However, the earlier or later occurrence of the westward movement of the jet has an influence on the process of the rain belt moving northward than the northward jump of the jet： the rain belt moves northward from the middle-lower Yangtze River valley to the Huaihe River and then to an area between the Yellow River and Huaihe River during years when the time of the westward movement of the jet core is later than that of the northward jump of the jet and from the middle-lower Yangtze River valley to an area between the Yellow River and Huaihe River in other years. Further analysis shows that： （1） The northward jump of the jet and the westward movement of the East Asian westerly jet core causes significant variation of the general atmospheric circulation in middle latitudes and water vapor transport from the western Pacific, but not from the Bay of Bengal. （2） Impact of the northward jump and the westward movement of the East Asian westerly jet core on circulation are different, therefore, water vapor transport from the western Pacific and its impact on the rain belt are different. The earlier or later occurrence of the westward movement of the jet core than the northward jump of the jet causes the process of circulation and water vapor transport to be different which produces a different process of the rain belt moving northward.
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By using the data which included the conventional weather chart,the satellite cloud image,the regional automatic meteorological station and the new generation of weather radar,the regional strong precipitation process which happened in Shandong Province during July 8-9 in 2009 was analyzed comprehensively.The results showed that Shandong Province was in the strong convergence zone of atmospheric vorticity in the low layer and the ascent zone of vertical velocity.The shear line was generated in the eastward process of northwest vortex,and the ground inverted trough extended to Shandong,which provided the dynamic condition for the formation of rainstorm.The coupling of jet stream in the high-low altitude enhanced the development of convection.The low-altitude jet stream was the main water vapor transportation channel,which provided the water vapor condition for the generation of rainstorm.The water vapor was mainly from the South China Sea and the Bay of Bengal.
文摘From June 18th to June 19th of 2009,Heilongjiang Province was hit by the regional rainstorm rarely paralleled in history.According to the findings based upon the conventional observation data,the precipitation occurred under the double-blocking situation of Ural Mountains and the Sea of Okhotsk.The main influencing systems were the upper vortex and northward low-pressure that came from Hetao area,accompanied by the delivery of high and low level jet stream.The results showed that the evolvement of blocking high,transfer of water vapor and configuration of high and low level jet stream were the key factors resulting in the rainfall process.
