地窝堡机场东南大风特征及其大气结构

按照民航系统气象行业标准要求,结合乌鲁木齐国际机场的具体情况,给出乌鲁木齐机场东南大风的定义,并应用乌鲁木齐机场1978~2012年间逐时观测的风速风向对机场东南大风的特征进行分析,然后再引入水跃理论和Froude数,对机场东南大风发生时的大气结构做解析。结果表明:(1)1980年代与2000年代至今,为东南大风的兴盛期,1990年代为东南大风的低值期;(2)东南大风主要集中出现在春秋季,其中尤以4月出现次数最多,占总出现次数的36.4%;(3)早晨至中午期间,东南大风多发且风速较大;午后至夜间,东南大风发生次数少,且风速也相对较小;(4)东南大风的持续时间以低于5 h为主,其次为持续11 h以上的大风,而持续时间在5~11 h之间的大风出现最少;(5)对于4月和11月而言,大风发生时达坂城与本场的气压差与同时次本场的温度垂直递减率存在显著的线性关系。

Characteristics of Southeast Gale and Its Corresponding Atmospheric Structure at Urumqi Airport

The southeast gale at Urumqi Airport was defined based on the civil aviation meteorological standards and the weather condition of Urumqi International Airport（ runway direction： 07 /25）. The characteristics of southeast gales at Urumqi Airport were analyzed by using hourly wind data from 1978 to 2012 measured at the airport,meanwhile,the corresponding atmospheric structure was also analyzed by introducing the Hydraulic Jump theory and the Froude number. The results are summarized as follows：（ 1） From the 1980s to the 2000s,the southeast gales occurred frequently,while in the 1990s it occurred less.（ 2） The southeast gales occurred maily in spring and fall,and 36. 4% of total occurrence times was in April.（ 3） In a day,from 07： 00 to 14： 00,the southeast gales occurred frequently and wind speed was relatively larger,while from afternoon to night,it occurred less and its wind speed was relatively small.（ 4） The durative time of a southeast gale was mainly less than five hours or more than 11 hours.（ 5） For April and November,there was a significant linear relationship between the vertical temperature lapse rate at the airport and the pressure gradient between Dabancheng and Urumqi Airport when the southeast gale occurred.