A study of vertical homogeneity of trace gases in Asian continental outflow
Abstract
The Asian continental outflows laden with particulate matters and trace gaseous pollutants can deteriorate air quality in the downwind region via long-range transport (LRT). To gain insightful knowledge of the mixing, transport, and vertical homogeneity of the outflows, as well as their relations with meteorological conditions in the boundary layer, whole air samples were collected at different altitudes over a coastal site of Taiwan during the season heavily influenced by Asian continental outflows for a weak and a strong cold frontal passages. The aerial samples from the near surface up to 700-m height were taken by a multi-rotor platform carrying a whole air sampling device. An array of 106 VOCs as well as CO, CH4, and CO2, sufficient to represent a wide range of sources and atmospheric reactivities, were analyzed to examine atmospheric mixing of gaseous pollutants. Simultaneously, aerial meteorological variables (temperature, humidity, wind direction and speed) from the near surface up to 1000-m height were also measured during the sampling flights. We observed very homogeneous vertical distributions of VOCs, CO, CH4, and CO2 during the passage of the two cold fronts, indicating a well-mixed condition for the Asian continental outflows. Furthermore, the stronger cold front as manifested by the greater higher wind speed and sharper decline in potential temperature with height, seems to exhibit greater homogeneity in vertical distribution.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.A31I2667C
- Keywords:
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- 0305 Aerosols and particles;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0322 Constituent sources and sinks;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0345 Pollution: urban and regional;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0368 Troposphere: constituent transport and chemistry;
- ATMOSPHERIC COMPOSITION AND STRUCTURE