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投稿时间:2009-09-13 修订日期:2010-07-22
投稿时间:2009-09-13 修订日期:2010-07-22
中文摘要: 利用湖北黄石长江南岸50 m高铁塔的风梯度、超声风及气温、湿度观测资料,对2007年5月31日及7月1—2日两场暴雨前后近地层风温湿场和降水前湍流特征进行了计算分析,探索其异常变化特征,为进一步认识黄石地区强降水的近地面层物理过程提供依据。结果表明:(1)降水前温度下降,湿度上升,平均风向发生明显转变,水平风速与垂直气流速度在降水前出现显著增大;降水后,风向平缓变化,平均风速再次增大。(2)垂直气流速度在降水前频繁上下振荡,激发湍流活动。(3)降水前湍流动能增大,湍流动量通量和感热通量增大向上传递,湍流强度逐步增大。湍流动能最大值的出现早于湍流通量,湍流活动在临近降水时进一步加强。可见暴雨发生前后近地层风温湿场有明显的变化,降水前湍流活动增强。
中文关键词: 暴雨, 近地层, 湍流, 物理要素
Abstract:Based on the observational data obtained from the 50m tower on the south bank of the Yangtze River in Huangshi, the paper has made detailed studies on two rainstorms occurring in 31 May and 1-2 July, 2007 respectively. The unusual characteristics can provide the basis to further know rainstorm’s surface layer physical process in Huangshi area. The results show that: (1) Before the rainstorm, the temperature drops together with the humidity rise, the direction of wind changes, and the horizontal wind speed and vertical airflow speed increase obviously. After the rainstorm, the wind direction changes gently and the wind speed increases once more; (2) The vertical airflow speed oscillates rapidly before the rainstorm, stimulating the turbulence; (3) The turbulent kinetic energy reaches the obvious peak and the flux transports the momentum and heat to the higher level, the turbulent intensity increases gradually. The maximal value of the turbulent kinetic energy appears ahead of the flux. The turbulence enhances when approaching rainfall. That is, obvious changes of the physical quantity field occur before and after rainstorm,the turbulence heightens ahead of the rainstorm.
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基金项目:国家重点工程项目“湖北鄂东长江公路气象观测论证与保障服务”(KY200601)和国家科技支撑计划项目(2008BAC48B02)气候研究开放实验室(LCS)开放课题资助
作者 | 单位 |
王林 | 中国地质大学大气物理与大气环境研究所, 武汉 430074 |
覃军 | 中国地质大学大气物理与大气环境研究所, 武汉 430074 中国气象局气候研究开放1实验室(LCS), 北京 100081 |
陈正洪 | 武汉区域气候中心, 武汉 430074 |
李建芳 | 陕西省宝鸡市气象局, 宝鸡 721006 |
引用文本:
王林,覃军,陈正洪,李建芳,2010.鄂东两次暴雨前后近地层物理量场异常特征分析[J].气象,36(12):28-34.
WANG Lin,QIN Jun,CHEN Zhenghong,LI Jianfang,2010.Study on the Abnormal Characteristics of Physical Quantity Fields at the Near Surface Layer for Two Rainstorm Processes in Huangshi of Eastern Hubei[J].Meteor Mon,36(12):28-34.
王林,覃军,陈正洪,李建芳,2010.鄂东两次暴雨前后近地层物理量场异常特征分析[J].气象,36(12):28-34.
WANG Lin,QIN Jun,CHEN Zhenghong,LI Jianfang,2010.Study on the Abnormal Characteristics of Physical Quantity Fields at the Near Surface Layer for Two Rainstorm Processes in Huangshi of Eastern Hubei[J].Meteor Mon,36(12):28-34.