| 杨贵名,孔期,毛冬艳,张芳华,康志明,宗志平. 2008. 2008年初“低温雨雪冰冻”灾害天气的持续性原因分析[J]. 气象学报, 66(5):836-849, doi:10.11676/qxxb2008.076 |
| 2008年初“低温雨雪冰冻”灾害天气的持续性原因分析 |
| Analysis of the long-lasting cryogenic freezing rain andsnow weather in the beginning of 2008 |
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| DOI：10.11676/qxxb2008.076 |
| 中文关键词: 低温雨雪冰冻天气，环流特征，冷暖气团，逆温，暴雪成因分析 |
| 英文关键词:Cryogenic freezing rain and snow weather, Circulation characteristics, Cold and warm air, Inversion, Causal analysis of snowstorm |
| 基金项目:科技部“科研院所社会公益研究专项课题”：不利气象条件对公路安全影响机理及对策研究项目(2004DIB3J100) |
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| 中文摘要: |
| 从预报角度出发，初步分析了2008年初“低温雨雪冰冻”天气的主要特点和环流特征，对冻雨、暴雪的成因也进行了初步分析：2008年初低温雨雪冰冻期间，大气环流形势稳定，极涡中心偏向于东半球，强而稳定，来自极地的冷气团与来自热带洋面的暖气团长时间在长江中下游地区交汇是主要原因；贝加尔湖以西地区阻塞高压强而稳定，中亚、西亚低槽（涡）位置稳定、发展活跃；对流层700 hPa等压面西南气流稳定，850 hPa低层多切变、低涡活动，为降水提供了非常有利的低空辐合条件；对流层中层高原有低涡发展，高原不断有正涡度向东传播至东部沿海；西太平洋副热带高压(副高)强盛，位置偏西、偏北；副热带锋区强盛，南北温度梯度大；南支槽比较活跃；华南准静止锋、滇黔准静止锋稳定维持；热带洋面上暖气团活跃；逆温层稳定，融化层厚度较厚，是长时间冻雨天气的主要原因之一。2008年初低温雨雪冰冻期间的第1次过程为强冷、暖气流共同作用所致，其后是华南、滇黔准静止锋稳定，扩散冷空气渗透所为；2008年初暴雪天气的主要因四川盆地有正涡度向东传播至中国东部沿海地区，水汽充沛，上升运动强烈所致。 |
| 英文摘要: |
| From the forecasting perspective, main characteristics of the cryogenic freezing rain and snow weather in the beginning of 2008 as well as associated circulation features have been analyzed. Meanwhile, we also studied the causes for the freezing rain and snow storms. During this period, the atmospheric circulation patterns were stable. The polar vortex was strong and located in the northern part of the East Hemisphere. The cold air from polar areas and warm air from the tropical sea confronted each other for a long time, which was considered as the main reason for this event. The blocking high in the west of the Baikal was robust, and the low trough (vortex) in central and western Asia was vigorous but less versatile in its position. The southwesterly flows were persistent at 700 hPa and there were active shears and vortex activities at 850 hPa, which provided a very favorable condition for the low-level convergence necessary for the subsequent rainfall. In mid troposphere, vortex activities developed over the Tibetan Plateau with positive vorticity propagating eastward to the coastal regions of eastern China. The western Pacific subtropical high was intensive, stretching westward and northward. The subtropical frontal zone was puissant, and the north to south temperature gradient was large. The quasi stationary fronts in Huanan and Yunnan-Guizhou were maintained steadily. The warm air over the tropical sea was active. The stable inversion layer and the thicker melting layer were one of the main reasons for the long time freezing rain. There were four episodes associated with this event. The first episode was resulted from the interaction between the cold and warm air. Later, the other episodes were caused by the quasi-stationary front in Huanan and Yunnan Guizhou, as well as the dispersed from the north cold air. The main reason for the snow storms in the beginning of 2008 was that positive vorticity in the Sichuan Basin propagated eastwards to the coastal regions of eastern China. Abundant water vapor and intense upward motion were very favorable for the intense snowfall. |
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