A Based on daily maximum and minimum temperature from Rongcheng station during 1981 -2010, the changing trends of extreme temperature indexes were analyzed. The results show that for the relative indexes, number of w...A Based on daily maximum and minimum temperature from Rongcheng station during 1981 -2010, the changing trends of extreme temperature indexes were analyzed. The results show that for the relative indexes, number of warm days （nights） in Rongcheng station showed an increasing trend, while the number of cold days （nights） showed a decreasing trend from 1981 to 2010, but the decreasing trend of number of cold days was small. For the extreme indexes, the extreme maximum temperature, the maximum of extreme minimum temperature and extreme mini- mum temperature increased, while the minimum of extreme maximum temperature decreased from 1981 to 2010. For the absolute indexes, the numbers of frozen days and frost days reduced, and frozen days were less than frost days for all year.展开更多
文摘利用2003-2013年地面观测资料、探空资料及NCEP 1°×1°再分析资料,分析了近10 a甘肃省雨雪转换的时空分布特征,获得了复杂地形条件下相态转换的温度预报组合指标,结果表明:(1)雨雪相态转化主要发生在过渡季节的春季和秋季,占总次数的83.5%,空间上有三个高发区。(2)相态的转换发生在高原槽东移产生降水的环流形势下,通常500 h Pa冷平流清晰并沿西北、西方、北方等3条路径影响甘肃。当沿西北路径移动时,高原槽主体深厚,冷平流强度最强,河东大部发生雨雪转换,当沿西方路径移动时,高原槽浅且位置偏南,北方冷空气较弱,仅高原边坡、陇中及陇东中南部出现转换。(3)T_(地面)>3.0℃、T_(地面)<-1.0℃、-1.0℃<T_(地面)<3.0℃是雨、雪、雨夹雪相态转换的前提条件,在此前提下获得了三类站点相态转换的不同层次温度组合指标,经检验,该指标预报效果较好。
基金Supported by the Scientific Research Project of Weihai Meteorological Administration in 2013(2013whqxz02)
文摘A Based on daily maximum and minimum temperature from Rongcheng station during 1981 -2010, the changing trends of extreme temperature indexes were analyzed. The results show that for the relative indexes, number of warm days （nights） in Rongcheng station showed an increasing trend, while the number of cold days （nights） showed a decreasing trend from 1981 to 2010, but the decreasing trend of number of cold days was small. For the extreme indexes, the extreme maximum temperature, the maximum of extreme minimum temperature and extreme mini- mum temperature increased, while the minimum of extreme maximum temperature decreased from 1981 to 2010. For the absolute indexes, the numbers of frozen days and frost days reduced, and frozen days were less than frost days for all year.
