摘要
利用平矩阵风廓线雷达于2007年7月17日至9月28日对上海世博园规划区上空的风垂直分布进行了观测。通过分析该地上空三维风场的日变化,发现夜间以偏西气流为主,白天风速较小,以偏东气流为主,表明该地区以海陆风为主导的环流特征是这一地区的局地环流日变化的基本特征。逐日变化分析表明,在8月2日以前主要以偏西北气流为主,之后基本是以东南气流为主,并且垂直运动特征以上升气流为主,强烈的垂直运动与偏西气流相关密切,同时偏北气流往往带来较强的上升运动。日夜平均廓线分析表明,夜间风速较大,并且夜间风速的垂直变化与白天相比也有很大不同,白天270 m以下风速随高度基本不变,而夜间从近地面向上风速随高度逐渐增大,低层<90 m的范围内白天风速大于夜间风速。城市冠层以上风向的日夜变化不明显,多为偏北气流控制。城郊风廓线的对比表明受城市下垫面粗糙度的影响,城市风速明显比郊区减小。城市和郊区的水平风速变化在城市冠层以上比较接近,相关系数达到了87%。
The wind velocity variations with height are observed over the EXPO Land, Shanghai using the flat array acoustic wind profiler from July 17 to September 28, 2007. This study shows the westerly domination in nighttime and easterly domination with low velocity variation at daytime by analyzing the diurnal variations of the local circulations, indicating sea-land wind significantly influences on the circulation in low atmospheric boundary layer. The day-to-day variations of wind velocity with height are characterized by north-westerly domination before August 2 and transiting to south-easterly from then on. The day- to-day variations of vertical wind velocity are dominated by updraft at most of days and the increased wind velocity connected with north-westerly. Nighttime averaged wind profile characterized by higher wind velocity and increasing with height is obvious different from that of daytime, which is almost constant with altitude below 270 m, except that daytime averaged wind velocity is higher than that of nighttime below 90 m and the steady northerly over urban canopy layer throughout the whole day. The wind speed of the city is lower than that of the suburb due to inhomogeneous underlying surface of city, and the difference of wind speed between the city and the suburb begins to decrease with the elevation with correlation coefficient of 87% at 330 m.
出处
《高原气象》
CSCD
北大核心
2009年第1期127-135,共9页
Plateau Meteorology
基金
国家自然科学基金项目“卫星遥感中国东部沿海气溶胶光学厚度”(40705013)
上海市气象局研究型专项“长三角气溶胶浓度卫星遥感技术的研制与应用”(YJ200701)
浙江省海洋气象科学研究所气象科技开放研究专项“MODIS遥感华东区域气溶胶算法及其验证”(Kf2006001)共同资助
关键词
上海世博园
风廓线
风雷达
边界层
EXPO land in Shanghai
Wind profile
Acoustic wind profiler
Boundary layer
