Abstract
In the spring of 2002, an intensive field measurement campaign was conducted to investigate the impact of Asian dust transport on local air quality in Taipei, Taiwan. The mass concentration, size distribution and chemical composition of the atmospheric aerosols were measured. Air quality data collected by the Taiwan EPA during this period were also analyzed. It was found that the content of crustal elements in aerosols could drastically increase on the arrival of air masses transported from the desert areas in Northwestern China and Mongolia. Time series analysis of aerosol measurements, air quality data, and meteorological conditions identified six Asian dust transport episodes occurring in the spring of 2002. In order to apportion the ambient aerosol burden between local and long-range sources, nitrogen oxides (NO(subscript x)) was chosen as a local pollution tracer and a simplified algorithm based on the NO(subscript x) and PM10 correlation was proposed. It was estimated that long-range transported aerosols contributed as much as 87% to the PM10 in Taipei on Feb. 11, the most intense dust event in 2002. A weak event that occurred on Mar. 23 contributed 35% to the PM10. Our results indicate that the air quality impact due to Asian transport dust is still important even during weak dust events.
Highlights
In the springtime, extreme weather conditions such as intense fronts and strong surface winds are induced frequently over Northwestern China and Mongolia
Over 100 μg m−3 occurred concurrently at Wan-Li and Ku-Tin. These high PM10 episodes are usually attributed to Asian dust transport
Asian dust episodes identified using time series analysis of air quality data was compared with those identified using aerosol compositions
Summary
Extreme weather conditions such as intense fronts and strong surface winds are induced frequently over Northwestern China and Mongolia. Public concern regarding the long-range transport of Asian dust has arisen in Taiwan due to its impact on the local air quality and, consequentially, public health. This concern has increased due to the co-transport of anthropogenic pollutants and dust in the Asian outflows To evaluate this health hazard, it is critical to determine the amount of particulate pollutants transported from the Asian continent during these dust events. This is not an easy task, because there are substantial local sources of air pollutants, in urban areas. The latter was selected because, in an analysis of temporal variations in air pollutants during Asian dust events, Lin et al (2004) noticed that NOX tended to represent local pollution the best as relatively little NOX came from long-range transport
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
