【摘要】 为研究2005年初和2008年初2次造成湖南电网严重冰灾的低温雨雪冰冻天气过程的成因,利用NCEP1°×1°全球再分析资料、地面常规气象观测资料及环流特征指数资料对过程期间高中低三层的水平和垂直结构进行了诊断分析,并分析了两次冰冻天气过程中各项环流特征指数与气温的相关性,结果表明:副高强度持续偏强,中层有暖层存在,850hPa与700hPa有明显的逆温层,700hPa强劲的西南急流,850hPa南北温差锋区的建立和维持,异常强大的冷高压长时间控制是造成两次冰灾过程的主要原因;地面降水、相对湿度、日平均气温、日最低气温、风向风速均与电线覆冰直径有关,温度垂直结构、环流指数和地形也与冰冻有一定关系。更多还原

【Abstract】 Two extremely ice disaster events attacked Hunan power grid in early 2005 and early 2008.In order to study cause of the two ice disaster processes,the horizontal and vertical structure of the high,medium and low level,the correlation between circulation characteristic index and temperature during two freezing weather processes were analyzed with the usage of the NCEP 1°×1° global analysis data,conventional observation data and circulation features index data,and it is found that,two ice disaster events were directly caused by continuous strong subtropical high strength,the existence of the middle-level warm layer,obvious inversion layer at 850hPa and 700hPa,southwestern jet flow at 700hPa,the formation and duration of north-and-south temperature front zone and longtime strong cold anticyclone.In the meantime,the research also discovered the precipitation,relative humidity,the average daily temperature,the minimum daily temperature,wind direction,wind speed,the temperature vertical structure,circulation index and terrains had some relation to the frozen weather.更多还原