博斯腾湖的湖陆风特征及其数值模拟研究

Characteristics and Numerical Simulation of the Lake/Land Breeze in Bosten Lake Area

采用基本气象站和区域气象站观测资料分析了2013年6月至2014年5月期间博斯腾湖的湖陆风日变化特征和季节特征,进而通过中尺度数值模拟分析博斯腾湖湖陆风的发展过程及其与天山山谷风的相互作用。结果表明,博斯腾湖北侧湖风与中天山南侧谷风叠加效应造成局地环流增强,从湖岸到山体,叠加效应造成的局地环流最大振幅表现出增大、减小、再增大的特点;湖岸区域湖风开始时间与距离的关系不显著,当离岸距离增大到约20 km以上,距离每增加约6 km,湖风开始时间推迟1 h;湖北侧湖风锋穿透内陆距离比受天山主体影响较小的湖南侧远约11 km;随着湖北侧湖风锋向天山靠近,湖风与谷风耦合作用不断加强。

Bosten Lake,one of the largest inland freshwater lakes in China,is located in the southern foot of the central Tianshan Mountains.The diurnal variation and seasonal characteristics of the lake/land breeze from June2013 to May 2014 were analyzed using the surface observation.Based on mesoscale numerical simulation,the development of lake/land breeze of Bosten Lake and its interaction with the mountain/valley breeze of Tianshan Mountains are explored.The results showthat local circulation enhancement caused by the coupling of the lake breeze in the north of the Bosten Lake and the valley breeze in the south of the central Tianshan Mountains.From the shore to the mountain,the maximum of the local wind has a variation of increase,decrease and then increase.The onset of Lake Breeze does not showa significant delay in the near shore area,and when the offshore distance is greater than 20 km,the onset of the lake breeze is delayed by 1 h every 6 km.The lake breeze fronts in the north of the Bosten Lake can move much more distance than in the south,where without the influence of big mountain.As the lake breeze fronts in the north of the Bosten Lake approached the mountain,the coupling of the lake breeze and the valley breeze strengthened.