海岸地区TIBL廓线与局地海风环流的数值试验

NUMERICAL EXPERIMENTS ON THE TIBL PROFILES AND THE LOCAL SEA BREEZE CIRCULATION IN COASTAL AREAS

关键词:  海风环流  TIBL廓线  能量闭合

Key words:  Sea breeze circulation  TIBL profile  Energy closure

摘要:

利用二维非线性能量(E-ε)闭合的边界层数值模式,研究了中纬度地区海岸日间局地海风环流的特征,并对不同海风特性条件下的TIBL高度廓线用幂指数关系进行了数学拟合。对大量的数值试验结果分析表明,TIBL廓线幂指数(α)的取值与海风特性有关,其大小在0.4-1.1之间,α=0.5只在海风充分发展时的陆上适用,文中还给出了不同海风发展程度(阶段)下的α取值。

Abstract:

A two dimensional nonlinear PBL numerical model using an energy closure (E-ε)method has been used to study the sea breeze circulation and TIBL in coastal areas.The main characteristics of sea breeze obtained from numerical experiments agree with those from general observation facts that are summarized by Atkinson(1987).The depth of sea breeze ranges from 300 to 900m, maximum velocity from 1.5 to 4m/s, and the height where max.velocity appears from 100 to 300m.The agreement between comparisons reveals that the performance of model is good,and the chosen experiment conditions are reasonable.This paper refitted the function of TIBL profiles also using the Weisman's relationship,but exponent value is changed with the different states of sea breeze.Many numerial experimental results indicate that the exponent of the TIBL profile,ranging from 0.4 to 1.1,is related with the strength and depth on the sea breeze.The exponent is 0.5 only when sea breeze is fully developed.This paper gives exponents under different sea breeze.