深圳中重度霾污染输送特征的数值模拟分析

Numerical simulations of transport characteristics of moderate-to-severe haze pollution in Shenzhen,China

对2008—2018年深圳出现的中重度霾污染事件进行天气分析的基础上,利用WRF-Chem模式采用敏感性试验的方法定量研究深圳及其周边城市(广州、东莞、惠州)人为排放源对深圳地区霾污染过程的贡献,揭示该地区霾污染过程的主要输送特征。影响深圳中重度霾污染过程的主要天气型为台风外围环流型及大陆高压(脊)型两类,其中大陆高压(脊)型又可根据风场进一步细分为3种类型:偏东北风型、风向多变型和偏南风型。典型污染个例的敏感性试验结果表明:台风外围环流型霾污染过程深圳本地贡献率为40.38%,其周边城市的总贡献率为22.6%;大陆高压(脊)型3种类型污染过程,深圳本地贡献率分别为21.12%、53.92%、55.41%,其周边城市的总贡献率分别为6.88%、10.97%、3.44%。风速和风向对输送特征的影响最为显著:当风速为3~4 m/s时,深圳本地贡献率可达50%;风速约6 m/s时,本地贡献率降为20%~40%,其周边城市输送的贡献率明显增大。不同城市对深圳霾污染的贡献受风向的影响有所差异,台风外围环流型个例主导风场多为西北风,此时东莞和惠州对深圳的贡献值分别为15.03%、1.77%;而其他风向时,东莞和惠州对深圳的贡献情况较为一致,其中,东北风时约3%,风向多变型时约5%,偏南风时1%~2%。广州对深圳的贡献率仅在台风外围环流型的西北风向时较为显著,可达5.8%。

Based on the analysis of weather of the moderate-to-severe haze pollution incidents in Shen‐zhen from 2008 to 2018,the WRF-Chem model and sensitivity tests were used to quantify the contribu‐tion of anthropogenic emission sources from Shenzhen and its surrounding cities(Guangzhou,Dong‐guan,and Huizhou)to the hazing process in Shenzhen using sensitivity tests,and to reveal the main transport characteristics of the hazing pollution process in the area.The main weather types affecting the process of moderate-to-severe haze pollution in Shenzhen are typhoon peripheral circulation pattern and Continental high(ridge)type,in which Continental high(ridge)type,can be further subdivided into three different types according to the wind field(north-east wind type,wind direction variable type,southerly wind type).The sensitivity tests of typical pollution cases show that under the typhoon peripheral circulation pattern during hazing pollution process,the local contribution rate of Shenzhen was 40.38%,and the total contribution rate of the surrounding cities was 22.6%.For the three types of Continental high(ridge)pollution processes,Shenzhen's local contribution rates were 21.12%,53.92%,and 55.41%,while the total contribution rates of the surrounding cities were 6.88%,10.97%,and 3.44%,respectively.Wind speed and orientation have the most significant impact on transport characteristics.When the wind speed was 3 to 4 m/s,the contribution rate of Shenzhen local sources can reach 50%.When the wind speed was about 6 m/s,the contribution rate of transmission in‐creased significantly while the local contribution rate decreased to 20%to 40%.The contribution of dif‐ferent cities was affected by wind directions.While the dominated wind field of typhoon peripheral cir‐culation pattern haze was mostly northwest,Dongguan and Huizhou's contribution differed,with 15.03%and 1.77%,respectively.In other scenarios,the contributions of these two cities were more consistent,about 1%to 5%.Guangzhou’s contribution to Shenzhen can reach 5.8%with the north‐west winds caused by the Typhoon peripheral circulation pattern.