中国污染物向北极地区传输的数值模拟研究

Numerical Simulation Study on the Transport of Pollution from China to the Arctic Region

利用NECP/NCAR FNL客观分析资料驱动中尺度模式WRF,通过4个数值试验模拟分析了2010年不同气象条件下(3月、6月、9月和12月),中国华南地区排放的示踪物向北极地区传输的总量、传输特征及传输机制。模拟结果表明,12月传输到北极地区的示踪物最多,约达到排放总量的44?;9月和6月的次之,约分别为7.5?和7?;3月的最少,只有0.105?。12月,示踪物传输到北极地区所需的时间最短,约为3天;9月和6月分别需要5天和6天;而3月,则需要9天时间。另外,不同月份示踪物传输到北极地区的主要通道所在高度也不同。3月主要集中在850~700 h Pa之间,9月在400~200 h Pa之间,而6月和12月在850 h Pa和200 h Pa的高度上都有浓度较高的传输通道出现。进一步分析发现,示踪物的传输路径主要受环流场控制。较强的经向南风和气旋系统有利于示踪物向北极地区传输;东亚大槽是导致12月排放的示踪物在较短时间内向北极地区传输较多的重要原因。

Using NECP/NCAR FNL objective analysis data driven mesoscale model WRF,four numerical experiments were conducted to simulate the total amount of traced emissions from South China to the Arctic region,investigating the transmission characteristics and related mechanisms under different weather conditions in March,June,September and December of 2010.The simulation results show that the peak concentration of emissions transported to the Arctic region was the highest in December,reaching 44? of the total emissions,followed by September and June,about 7.5?and 7?respectively,and the lowest in March,which was only 0.105?.The emissions from South China to Arctic need 3 days in December,need respectively 5 and 6 days in September and June,and takes 9 days in March.In addition,the peak levels of absolute concentrations of emissions emitted to the Arctic under different weather conditions are also different,the emissions were mainly from 850 to 700 hPa in March and from 400 to 200 hPa in September,and in June and December appear at 850~200 hPa.Further analysis found that the path of emission transport is mainly controlled by the circulation field,and the strong radial south wind and cyclone systems facilitate the transmission of emissions to the Arctic.The East Asian trough is an important reason for the transport of traced emissions to the Arctic in a short period of time.