昆明城市热岛效应的数值模拟研究  

A Numerical Simulation of Urban Heat Island Effect in Kunming

作　　者：周晓宇 王咏薇[2] 孙绩华[3] 段玮[3] 杨大虎 Xiaoyu ZHOU;Yongwei WANG;Jihua SUN;Wei DUAN;Dahu YANG(Yuxi Meteorological Bureau,Yuxi,Yunnan 653100;College of Atmospheric Physics,Nanjing University of Information Science and Technology,Nanjing 210044;Yunnan Meteorological Bureau,Kunming 650034)

机构地区：[1]玉溪市气象局,云南玉溪653100 [2]南京信息工程大学大气物理学院,南京210044 [3]云南省气象局,昆明650034

出　　处：《大气科学》2022年第4期921-935,共15页Chinese Journal of Atmospheric Sciences

基　　金：第二次青藏高原综合科学考察研究项目2019QZKK0105。

摘　　要：本文利用WRF(V3.9.1)模式中耦合Noah/SLUCM方案作为Control试验,研究了土地利用类型(Md04试验)、陆面过程(NoUCM试验)和湖泊(Nolake试验)对城市热岛强度及昆明城市气象要素水平、垂直的时空分布影响。主要结论如下:(1)四个试验城市热岛强度的平均日变化趋势相似,白天城市热岛强度较弱、夜间较强,在20时(北京时,下同)左右达到最大值。城市冠层(湖泊)对城市热岛有较明显的减(增)温,Control-NoUCM(Nolake)试验中,平均日最大差值为−0.79°C(+1.07°C)。(2)从能量平衡方程分析Control-Md04试验,感热(潜热)通量的差值为+46.18(−79.71)W m^(−2),潜热通量释放大于感热通量的绝对值。Control-NoUCM试验中,感热(潜热)通量的差值为−40.88(+29.60)W m^(−2);因NoUCM试验未考虑几何建筑物储热与遮挡,太阳辐射大部分被地表所吸收,导致感热通量偏大。(3)四种试验中,15(07)时边界层高度达到最大(小)值。NoUCM(Nolake)试验中城市边界层高度分别降低103 m(32 m)左右,而Md04试验中城市边界层高度增加102 m左右。(4)湖泊(滇池)对城市热岛环流影响的试验表明,湖泊上空垂直运动较弱,但水平方向湖陆风较大,这有利于向城市输送水汽,增加干空气湿度,使城市中空气的水汽含量增加,同时增大潜热能量释放,降低感热通量,减小了垂直温度梯度。This paper uses the coupling Noah/Single-layer Urban Canopy scheme coupled with WRF(V3.9.1)model is used as a Control experiment to investigate the effects of land-use type(Md04 experiment),land surface process(NoUCM experiment),and lake(Nolake experiment)on the intensity of urban heat island,and the horizontal and vertical spatial distribution characteristics of urban meteorological elements in Kunming.The following are the main findings:(1)In all four experiments,the average daily variation trend of urban heat island intensity is almost similar.The urban heat island(UHI)intensity is low during the daytime and high at night,peaking at around 2000 BJT(Beijing time).The average daily maximum difference for Control-NoUCM(Nolake)is−0.79°C(+1.07°C).(2)The difference of the sensible heat(latent heat)flux is+46.18(−79.71)W m^(−2) based on the energy balance equation analysis of the Control-Md04 experiment,and the release of latent heat flux is greater than the absolute value of the sensible heat flux.In the Control-NoUCM experiment,the sensible heat(latent heat)flux difference is−40.88(+29.60)W m^(−2).The NoUCM experiment does not take into account the heat storage and shielding of geometric buildings.The land surface absorbs the majority of solar radiation,resulting in a large absolute value of the sensible heat flux.(3)The boundary layer height reaches its maximum(minimum)value at 1500(0700)BJT in all four experiments.The height of the urban boundary layer decreased by approximately 103 m(32 m)in NoUCM(Nolake),while it increased by approximately 102 m in Md04 experiment.(4)The numerical simulation results of the influence of the lake(Dianchi lake)on the circulation of urban heat islands show that the vertical movement over the lake is weak,but the horizontal lake-land breeze is strong.The breeze’s circulation benefits from the transportation of water vapor to the city center,which increases the humidity of dry air and enlarges the water vapor content.Furthermore,it increases the release of latent heat f

关 键 词：城市热岛 WRF模式 城市冠层 土地利用类型 湖陆风 

分 类 号：P401[天文地球—大气物理学与大气环境]