Atmospheric lifetimes and traveling distances of 15 PAHs(Ac:acenaphthylene,Ace:acenaphthene,Ph:phenanthrene,MePh3:3-methyl-phenanthrene,MePh9:9-methyl-phenanthrene,MePh1:1-methyl-phenanthrene,MePh2:2-methyl-phenanthre...Atmospheric lifetimes and traveling distances of 15 PAHs(Ac:acenaphthylene,Ace:acenaphthene,Ph:phenanthrene,MePh3:3-methyl-phenanthrene,MePh9:9-methyl-phenanthrene,MePh1:1-methyl-phenanthrene,MePh2:2-methyl-phenanthrene,Ret:retene,B[a]A:benzo[a]anthracene,Chry:chrysene,B[b,j,k]F:benzo[b,j,k]fluoranthene,B[e]P:benzo[e]pyrene,B[a]P:benzo[a]pyrene,Ind:indeno[1,2,3-cd]pyrene,B[g,h,i]P:benzo[g,h,i]perylene)at Whitbourne,UK,were estimated by using the rate constants for reaction with OH,O3,and the first order rate constants of eight species of high molecular weight PAHs(i.e.B[a]A,Chry,B[b]F,B[k]F,B[a]P,Ind,B[g,h,i]P and Ret)as a function of humidity,solar intensity and temperature by using Multiple Regression Analysis.The predicted atmospheric lifetime of Ac,Ace,Ph,MePh3,MePh9,MePh2 and MePh1 ranged between 11.42 h-79.12 h in cold period and 1/31 h-14.33 h in warm period respectively.The binary ratios of atmospheric lifetime of B[k]F/B[g,h,i]P,B[k]F/B[g,h,i]P,B[g,h,i]P/Ind and B[k]F/Ind displayed non-significant differences between cold and warm period,indicating that high molecular weight PAHs are difficult to be decomposed by UV light and thus may be conveyed to the rural regions via long range atmospheric transportation(LRAT).The decreased level of the atmospheric lifetime of low molecular weight PAHs in summer can be attributed to an increased level of OH radical content and solar radiation.展开更多
利用国家基准站降水观测数据、ERA5(European Centre for Medium-Range Weather Forecasts Reanalysis v5)再分析资料和WRF(Weather Research and Forecasting)中尺度数值模式,研究了水汽输送、收支及北段太行山地形对“23·7”河...利用国家基准站降水观测数据、ERA5(European Centre for Medium-Range Weather Forecasts Reanalysis v5)再分析资料和WRF(Weather Research and Forecasting)中尺度数值模式,研究了水汽输送、收支及北段太行山地形对“23·7”河北中部极端降水过程的影响。结果表明:1)偏北偏强的副热带高压西伸和大陆高压打通形成“高压坝”,阻挡减弱台风“杜苏芮”的北上,加之西北太平洋台风“卡努”东移的共同影响,建立了两条水汽通道(1000~700 hPa),一条为西太平洋水汽通道,水汽主要集中在1000~900 hPa;另一条为南海水汽通道,水汽主要集中在900~850 hPa。2)河北中部主要的水汽输入边界为南边界和东边界,且以南边界为主,主要的水汽输出边界为北边界和西边界。河北中部小时降水量与区域水汽通量净收支呈正相关,2023年7月30日河北中部的水汽通量净收支约为29日和31日的4.7倍,为极端降水的发生发展提供有利的水汽条件。3)太行山地形对此次暴雨的落区和强度有一定的影响。受到北段太行山的阻挡,远距离输送的水汽在山前迎风坡及山前平原堆积。地表至700 hPa,东北风/偏东风在山前迎风坡强迫抬升,且山前平原处稳定存在东南风与东北风的辐合,有利于山前迎风坡至山前平原一带稳定维持强盛而持久的垂直上升运动,这种较强且深厚的水汽辐合和垂直输送利于河北中部产生强降水。展开更多
文摘Atmospheric lifetimes and traveling distances of 15 PAHs(Ac:acenaphthylene,Ace:acenaphthene,Ph:phenanthrene,MePh3:3-methyl-phenanthrene,MePh9:9-methyl-phenanthrene,MePh1:1-methyl-phenanthrene,MePh2:2-methyl-phenanthrene,Ret:retene,B[a]A:benzo[a]anthracene,Chry:chrysene,B[b,j,k]F:benzo[b,j,k]fluoranthene,B[e]P:benzo[e]pyrene,B[a]P:benzo[a]pyrene,Ind:indeno[1,2,3-cd]pyrene,B[g,h,i]P:benzo[g,h,i]perylene)at Whitbourne,UK,were estimated by using the rate constants for reaction with OH,O3,and the first order rate constants of eight species of high molecular weight PAHs(i.e.B[a]A,Chry,B[b]F,B[k]F,B[a]P,Ind,B[g,h,i]P and Ret)as a function of humidity,solar intensity and temperature by using Multiple Regression Analysis.The predicted atmospheric lifetime of Ac,Ace,Ph,MePh3,MePh9,MePh2 and MePh1 ranged between 11.42 h-79.12 h in cold period and 1/31 h-14.33 h in warm period respectively.The binary ratios of atmospheric lifetime of B[k]F/B[g,h,i]P,B[k]F/B[g,h,i]P,B[g,h,i]P/Ind and B[k]F/Ind displayed non-significant differences between cold and warm period,indicating that high molecular weight PAHs are difficult to be decomposed by UV light and thus may be conveyed to the rural regions via long range atmospheric transportation(LRAT).The decreased level of the atmospheric lifetime of low molecular weight PAHs in summer can be attributed to an increased level of OH radical content and solar radiation.
文摘利用国家基准站降水观测数据、ERA5(European Centre for Medium-Range Weather Forecasts Reanalysis v5)再分析资料和WRF(Weather Research and Forecasting)中尺度数值模式,研究了水汽输送、收支及北段太行山地形对“23·7”河北中部极端降水过程的影响。结果表明:1)偏北偏强的副热带高压西伸和大陆高压打通形成“高压坝”,阻挡减弱台风“杜苏芮”的北上,加之西北太平洋台风“卡努”东移的共同影响,建立了两条水汽通道(1000~700 hPa),一条为西太平洋水汽通道,水汽主要集中在1000~900 hPa;另一条为南海水汽通道,水汽主要集中在900~850 hPa。2)河北中部主要的水汽输入边界为南边界和东边界,且以南边界为主,主要的水汽输出边界为北边界和西边界。河北中部小时降水量与区域水汽通量净收支呈正相关,2023年7月30日河北中部的水汽通量净收支约为29日和31日的4.7倍,为极端降水的发生发展提供有利的水汽条件。3)太行山地形对此次暴雨的落区和强度有一定的影响。受到北段太行山的阻挡,远距离输送的水汽在山前迎风坡及山前平原堆积。地表至700 hPa,东北风/偏东风在山前迎风坡强迫抬升,且山前平原处稳定存在东南风与东北风的辐合,有利于山前迎风坡至山前平原一带稳定维持强盛而持久的垂直上升运动,这种较强且深厚的水汽辐合和垂直输送利于河北中部产生强降水。
