首页 | 本学科首页   官方微博 | 高级检索  
     检索      

植被下垫面Z0的估算及其改进影响评估
引用本文:田春艳,崔寅平,申冲,陈修治,沈傲,樊琦.植被下垫面Z0的估算及其改进影响评估[J].中国环境科学,2022,42(9):3969-3982.
作者姓名:田春艳  崔寅平  申冲  陈修治  沈傲  樊琦
作者单位:1. 中山大学大气科学学院, 广东省气候变化与自然灾害研究重点实验室, 南方海洋科学与工程广东省实验室(珠海), 广东 珠海 519082;2. 中国民用航空中南地区空中交通管理局气象中心, 广东 广州 510000;3. 广州市气候与农业气象中心, 广东 广州 511430
基金项目:国家重点研发计划(2019YFC0214605);国家自然科学基金资助项目(42075181);广东省科技计划项目(科技创新平台类)(2019B121201002);广东省气候变化与自然灾害研究重点实验室(2020B1212060025)
摘    要:利用卫星遥感反演数据和多种观测资料,基于形态学-遥感反演的方法,估算我国主要植被下垫面的空气动力学粗糙度长度(Z0),将其应用于区域大气化学模式(WRF-Chem)中改进模式默认Z0值,并结合全国气象和污染物观测数据进行改进效果评估,探究Z0改进对模式气象场和化学场模拟结果的影响.结果表明:(1)Z0高值主要位于森林类下垫面,可超过1m;农田、草地类下垫面Z0值较小,低于0.5m,其余植被下垫面的Z0值基本介于两者之间.(2)Z0改进后,10m风速(WS10)和地表温度(TSK)的改进效果较好,而2m温度(T2)和相对湿度(RH)的改进效果不明显;从空间分布和不同下垫面结果来看,Z0对TSK主要是增温作用,对WS10是减小作用;就改进比(各要素改进后的模拟值与改进前的模拟值之差比上改进前的模拟值,下同)而言,Z0改进对WS10的影响大于TSK.从对污染物浓度效果评估看,Z0对PM2.5和PM10模拟改进效果较好,对其它污染物(SO2、NO2、O3)的改进效果不明显.(3)对比气象要素和污染物浓度效果评估可知,Z0改进对气象要素的影响大于污染物浓度,其主要是通过影响气象场来间接影响污染物浓度.总的来看,Z0改进影响最大的是气象场的10m风速,考虑其原因在于改进后的Z0普遍高于改进前模式默认Z0值,而Z0是表征地表粗糙度的变量,由于地表粗糙度的增加,增强了对气流的阻碍作用,使得近地层风速减小.

关 键 词:空气动力学粗糙度长度  植被下垫面  数值模拟  WRF-Chem模式  PM2.5  
收稿时间:2022-02-21

Estimation of vegetation underlying surface Z0 and assessment on the impacts of its improvement
TIAN Chun-yan,CUI Yin-ping,SHEN Chong,CHEN Xiu-zhi,SHEN Ao,FAN Qi.Estimation of vegetation underlying surface Z0 and assessment on the impacts of its improvement[J].China Environmental Science,2022,42(9):3969-3982.
Authors:TIAN Chun-yan  CUI Yin-ping  SHEN Chong  CHEN Xiu-zhi  SHEN Ao  FAN Qi
Institution:1. Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies, Southern Laboratory of Ocean Science and Engineering (Zhuhai), School of Atmospheric Sciences, Sun Yat-sen University, Zhuhai 519082, China;2. Meteorological Center of Middle South Regional Air Traffic Management Bureau of CAAC, Guangzhou 510000, China;3. Guangzhou Climate and Agrometeorology Center, Guangzhou 511430, China
Abstract:The morphology-remote sensing inversion with satellite remote sensing and multi-observation data were utilized to estimate the aerodynamic roughness length (Z0) of main vegetation underlying surfaces in China. This new Z0 dataset was then used to replace the default values in the WRF-Chem model. Combined with the national meteorological and pollutant observation data, the impacts of Z0 improvement on the meteorological field and chemical field simulations were evaluated. The results show that the high value of Z0 is mainly located over the forest underlying surface (higher than 1m); the Z0 values over the farmland and grassland underlying surfaces are generally lower (lower than 0.5m). The Z0 values over other underlying surfaces fell in between 0.5m and 1m; and the modification of Z0 has a better improvement in the simulations of 10m wind speed (WS10) and surface temperature (TSK) even though its effects on 2m temperature (T2) and relative humidity (RH) are not obvious. We also observed that an increase in Z0 mainly has a warming effect on TSK and a weakening effect on WS10 for different types of underlying surfaces. In terms of the improvement ratio (the difference between the simulated value after the improvement of each element and the simulated value before the improvement divided by the simulated value before the improvement, the same below), the improved Z0 demonstrates a greater impact on WS10 than on TSK. For the pollutant concentrations, the modification of Z0 has larger effects on the simulations for PM2.5 and PM10 than for other pollutants (SO2, NO2, O3). Furthermore, the impact of the improved Z0 was larger on meteorological elements than on pollutant concentrations. In general, the improvement of Z0 has the largest impact on the 10m wind speed; because the improved Z0 is generally higher than the model-default Z0 value. As Z0 is a variable for characterizing the surface roughness, the obstruction to the air flow increases with an increase in surface roughness and thus results in a reduction in the near surface wind speed.
Keywords:aerodynamic roughness length  vegetation underlying surface  numerical simulation  WRF-Chem model  PM2  5  
点击此处可从《中国环境科学》浏览原始摘要信息
点击此处可从《中国环境科学》下载免费的PDF全文
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号