四维通量法在珠三角地区秋季PM_(2.5)区域输送研究中的应用

Application of four-dimensional flux method in PM_(2.5) regional transportation in the Pearl River Delta during the autumn season

为探讨珠三角地区秋季PM_(2.5)区域输送对广州的影响,选取2015年10月19日—11月26日为研究时段,利用四维通量法,并结合WRF-CMAQ模式,计算与广州相邻的7个城市边界线上PM_(2.5)在不同高度的输送量。结果表明:15km高度内,广州的PM_(2.5)输入来自清远、东莞、深圳,向佛山、惠州、韶关、中山输出;输入量大小依次为清远、东莞、深圳,输出量大小依次为中山、韶关、惠州、佛山;垂直方向上,2km以下高度,PM_(2.5)输送以输出广州为主,2km以上高度,PM_(2.5)输送以输入广州为主;日间13:00—18:00为PM_(2.5)输送强度的高峰期,且该时段的PM_(2.5)净输送量以清远与佛山的输入为主。

To investigate the impact of regional transportation on PM 2.5 in Guangzhou, the dates from October 19th, 2015 to November 26th, 2015 was selected as research period, and WRF/CMAQ model coupled with four-dimensional flux method was applied in this study to estimate the transboundary flux of PM 2.5 between Guangzhou and adjacent boundary under the different heights. The results showed that input flux of PM 2.5 below the height of 15 km in Guangzhou mainly came from Qingyuan, Dongguan, Shenzhen, while the output flux of PM 2.5 mainly found in Zhongshan,Huizhou, Shaoguan and Foshan. The highest input flux was found in Qingyuan, followed by Dongguan, and Shenzhen.While the output flux was the highest in Zhongshan, followed by Shaoguan, Huizhou and Foshan. In terms of vertical distribution, the net flux of PM 2.5 mainly transported from Guangzhou to surrounding cities below the height of 2 km, while the flux showed an opposite trend above the height of 2 km. In addition, the transported flux intensity peaked at 13:00-18:00,and the flux mainly transported from Qingyuan and Foshan to Guangzhou.