Air pollutants and aerosol composition measured in winters and springs of 2000 and 2001 were analyzed to study the impact of long-range transport of air pollutants and dust from the Asian continent on the particulate ...Air pollutants and aerosol composition measured in winters and springs of 2000 and 2001 were analyzed to study the impact of long-range transport of air pollutants and dust from the Asian continent on the particulate pollutants of aerosols in Taiwan. Although Asian dust storms were the most spectacular phenomenon in terms of the impact on the aerosol concentration, they accounted for less than 15% of the PM 10 in Taiwan during winter and spring. The primary long-range transport process can be clearly identified to be the prevailing northeasterly following the cold front of winter monsoon that originates in the Asian continent. However, concentrations of pollutants associated with each cold front changed greatly from one front to another, apparently depending on the air-mass trajectory and vertical mixing. We estimate that the long-range transport of particulate pollutants contribute to about 30 μgm -3 to the PM10 concentrations in northern and eastern Taiwan. A smaller contribution is estimated for the western plain of Taiwan. For sulfate, nitrate, and ammonium ions, the long-range transport contributes about 10 μg/m 3, 3 μg/m 3, and 3 μg/m 3, respectively. Contributions of the long-range transport to CO and O 3 are also substantial, about 230 ppb and 40 ppb, respectively.展开更多
文摘Air pollutants and aerosol composition measured in winters and springs of 2000 and 2001 were analyzed to study the impact of long-range transport of air pollutants and dust from the Asian continent on the particulate pollutants of aerosols in Taiwan. Although Asian dust storms were the most spectacular phenomenon in terms of the impact on the aerosol concentration, they accounted for less than 15% of the PM 10 in Taiwan during winter and spring. The primary long-range transport process can be clearly identified to be the prevailing northeasterly following the cold front of winter monsoon that originates in the Asian continent. However, concentrations of pollutants associated with each cold front changed greatly from one front to another, apparently depending on the air-mass trajectory and vertical mixing. We estimate that the long-range transport of particulate pollutants contribute to about 30 μgm -3 to the PM10 concentrations in northern and eastern Taiwan. A smaller contribution is estimated for the western plain of Taiwan. For sulfate, nitrate, and ammonium ions, the long-range transport contributes about 10 μg/m 3, 3 μg/m 3, and 3 μg/m 3, respectively. Contributions of the long-range transport to CO and O 3 are also substantial, about 230 ppb and 40 ppb, respectively.
