TY - JOUR
T1 - The effects of synoptical weather pattern and complex terrain on the formation of aerosol events in the Greater Taipei area
AU - Chuang, Ming Tung
AU - Chiang, Pen Chi
AU - Chan, Chang Chuan
AU - Wang, Chu Fang
AU - Chang, E. E.
AU - Lee, Chung Te
N1 - Funding Information:
We express our deep gratitude to the Taiwan National Science Council for providing financial support to this study (NSC 94-2111-M-008-021-AGC). Likewise, we thank the Taiwan Environmental Protection Administration (TEPA) for providing monitoring data on the Taiwan aerosol supersite. Also, we acknowledge the Data Bank of Atmospheric Research (DBAR), managed by the Department of Atmospheric Sciences, National Taiwan University for sharing the atmospheric monitoring data used in this study.
PY - 2008/7/25
Y1 - 2008/7/25
N2 - The aerosol in the Taipei basin is difficult to transport outward under specific weather patterns owing to complex terrain blocking. In this study, seven weather patterns are identified from synoptic weather maps for aerosol events, which occurred from March 2002 to February 2005. Among the identified weather patterns, High Pressure Peripheral Circulation (HPPC), Warm area Ahead of a cold Front (WAF), TYPhoon (TYP), Pacific High Pressure system stretching westerly (PHP), Weak High Pressure system (WHP), and Weak Southern Wind (WSW) are related to terrain blocking. The remaining pattern is High Pressure system Pushing (HPP). The classification of the pollution origin of the air masses shows that 15% of event days were contributed by long-range transport (LRT), 20% by local pollution (LP), and 65% by LRT/LP mix. Terrain blocking causes aerosol accumulation from high atmospheric stability and weak winds occurring under HPPC, TYP, and PHP weather patterns when the Taipei basin is situated on the lee side of the Snow Mountains Chain (SMC). Terrain blocking also occurs when the Taipei basin is situated on the upwind of SMC and Mt. Da-Twen under WAF and WSW patterns. To study the variation of aerosol properties under the mixed influence of terrain and pollution origin, we conducted a field observation simultaneously at the urban, suburban, and background sites in the Greater Taipei area from April 14 to 23, 2004. Terrain blocking plays an important role in aerosol accumulation in the stagnant environment when the Taipei basin is on the lee side of SMC. On the other hand, the PM2.5 sulfate level is stable with a fraction of 30% in PM2.5 during the observation period at the urban (25%-33%) and background (25%-41%) sites. It indicates that background PM2.5 sulfate is high on the West Pacific in winter.
AB - The aerosol in the Taipei basin is difficult to transport outward under specific weather patterns owing to complex terrain blocking. In this study, seven weather patterns are identified from synoptic weather maps for aerosol events, which occurred from March 2002 to February 2005. Among the identified weather patterns, High Pressure Peripheral Circulation (HPPC), Warm area Ahead of a cold Front (WAF), TYPhoon (TYP), Pacific High Pressure system stretching westerly (PHP), Weak High Pressure system (WHP), and Weak Southern Wind (WSW) are related to terrain blocking. The remaining pattern is High Pressure system Pushing (HPP). The classification of the pollution origin of the air masses shows that 15% of event days were contributed by long-range transport (LRT), 20% by local pollution (LP), and 65% by LRT/LP mix. Terrain blocking causes aerosol accumulation from high atmospheric stability and weak winds occurring under HPPC, TYP, and PHP weather patterns when the Taipei basin is situated on the lee side of the Snow Mountains Chain (SMC). Terrain blocking also occurs when the Taipei basin is situated on the upwind of SMC and Mt. Da-Twen under WAF and WSW patterns. To study the variation of aerosol properties under the mixed influence of terrain and pollution origin, we conducted a field observation simultaneously at the urban, suburban, and background sites in the Greater Taipei area from April 14 to 23, 2004. Terrain blocking plays an important role in aerosol accumulation in the stagnant environment when the Taipei basin is on the lee side of SMC. On the other hand, the PM2.5 sulfate level is stable with a fraction of 30% in PM2.5 during the observation period at the urban (25%-33%) and background (25%-41%) sites. It indicates that background PM2.5 sulfate is high on the West Pacific in winter.
KW - Aerosol event
KW - Aerosol properties
KW - Atmospheric aerosols
KW - Complex terrain
KW - Synoptical weather pattern
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U2 - 10.1016/j.scitotenv.2008.01.051
DO - 10.1016/j.scitotenv.2008.01.051
M3 - Article
C2 - 18485452
AN - SCOPUS:44649155639
SN - 0048-9697
VL - 399
SP - 128
EP - 146
JO - Science of the Total Environment
JF - Science of the Total Environment
IS - 1-3
ER -
