上海北侧区域海陆风对污染物扩散的影响  

Effects of land and sea breeze on pollutant diffusion in northern Shanghai

作　　者：肖犇 贾洪伟 徐佳佳 亢燕铭[1] 钟珂[1] XIAO Ben;JIA Hong-wei;XU Jia-jia;KANG Yan-ming;ZHONG Ke(College of Environmental Science and Engineering,Donghua University,Shanghai 201620,China)

机构地区：[1]东华大学环境科学与工程学院,上海201620

出　　处：《中国环境科学》2022年第4期1552-1561,共10页China Environmental Science

基　　金：上海市科学技术委员会科研计划项目(19DZ1205005);国家自然科学基金资助项目(42075179)。

摘　　要：利用数值模拟方法研究了上海北侧区域海陆风对污染物扩散的影响,包括上海城郊-崇明岛-启东市区及这三区域之间的北支水道与南支水道.使用当量法表征太阳辐射和长波辐射引起的近地面空气热量变化,模拟结果与ECMWF再分析数据呈现较好的一致性.结果表明,在海风阶段,宽海(南支水道)、窄海(北支水道)区域都能形成海风,前者较后者发生时间早约1h;在陆风阶段,仅宽海两侧有陆风出现,其中来自上海陆地的陆风可以穿越宽海抵达崇明.海风对大气污染物扩散和稀释的效果取决于海风锋面与污染物的时空关系,当污染物位于锋面之前,则会被海风锋面卷入回流带至高空,海风起到清洁的效果;当污染物位于海风锋面之后,锋面后的海风则会将污染物推至内陆,造成持久的污染.陆风能将凌晨时分释放的污染物吹离上海陆地区域,但污染物会随着陆风登录崇明区域恶化当地空气质量;清晨时分释放的污染物只会被陆风吹至近海区域,并会随着之后的海风二次污染陆地区域.The north side of Shanghai has complex sea and land terrain and is a heavily polluted area. Numerical simulation method is employed to study the influences of sea and land breeze on pollutant diffusion in this area, including the zones of Shanghai suburb-Chongming Island-Qidong and the north branch channel and the south branch channel between the three areas. The equivalent method is adopted to characterize the near ground air heat change caused by solar radiation and long wave radiation. The simulations are in good agreement with ECMWF reanalysis data. The results show that the sea breeze forms in both the wide sea(South Branch waterway) and the narrow sea(North Branch waterway) regions during the sea breeze period, and the former one occurs about one hour earlier than the latter. During the land breeze period, only the two sides of the wide sea have obvious land breeze, among which land winds from Shanghai can cross the wide sea region to Chongming. The effect of the sea breeze on the diffusion and dilution of air pollutants depends on the temporal and spatial relationship between the sea breeze front and the pollutants. When the pollutants are discharged and accumulated before the sea breeze front, they will be drawn into the reflux zone by the front to the high altitude, and the sea breeze blows with a cleaning effect. Conversely, when the pollutants are emitted and dispersed behind the sea breeze front, the sea breeze will push the pollutants into the inland area and cause a lasting pollution process.The land wind blows the pollutants discharged at midnight away from the Shanghai land area, but the pollutants will enter the Chongming area with the land wind, and deteriorate the local air quality. The pollutants emitted in the early morning will only be blown to the offshore area by the land wind, and will pollute the land area again with the subsequent sea wind.

关 键 词：复杂海陆地形 海陆风 数值模拟 空气质量 

分 类 号：X51[环境科学与工程—环境工程] P425.41[天文地球—大气科学及气象学]