TY - JOUR
T1 - Multiscale simulations of tropospheric chemistry in the eastern Pacific and on the U.S. West Coast during spring 2002
AU - Tang, Youhua
AU - Carmichael, Gregory R.
AU - Horowitz, Larry W.
AU - Uno, Itsushi
AU - Woo, Jung Hun
AU - Streets, David G.
AU - Dabdub, Donald
AU - Kurata, Gakuji
AU - Sandu, Adrian
AU - Allan, James
AU - Atlas, Elliot
AU - Flocke, Frank
AU - Huey, Lewis Gregory
AU - Jakoubek, Roger O.
AU - Millet, Dylan B.
AU - Quinn, Patricia K.
AU - Roberts, James M.
AU - Worsnop, Douglas R.
AU - Goldstein, Allen
AU - Donnelly, Stephen
AU - Schauffler, Sue
AU - Stroud, Verity
AU - Johnson, Kristen
AU - Avery, Melody A.
AU - Singh, Hanwant B.
AU - Apel, Eric C.
PY - 2004/12/16
Y1 - 2004/12/16
N2 - Regional modeling analysis for the Intercontinental Transport and Chemical Transformation 2002 (ITCT 2K2) experiment over the eastern Pacific and U.S. West Coast is performed using a multiscale modeling system, including the regional tracer model Chemical Weather Forecasting System (CFORS), the Sulfur Transport and Emissions Model 2003 (STEM-2K3) regional chemical transport model, and an off-line coupling with the Model of Ozone and Related Chemical Tracers (MOZART) global chemical transport model. CO regional tracers calculated online in the CFORS model are used to identify aircraft measurement periods with Asian influences. Asian-influenced air masses measured by the National Oceanic and Atmospheric Administration (NOAA) WP-3 aircraft in this experiment are found to have lower ΔAcetone/ΔCO, ΔMethanol /ΔCO, and ΔPropane/ ΔEthyne ratios than air masses influenced by U.S. emissions, reflecting differences in regional emission signals. The Asian air masses in the eastern Pacific are found to usually be well aged (>5 days), to be highly diffused, and to have low NOy levels. Chemical budget analysis is performed for two flights, and the O3 net chemical budgets are found to be negative (net destructive) in the places dominated by Asian influences or clear sites and positive in polluted American air masses. During the trans-Pacific transport, part of gaseous HNO3 was converted to nitrate particle, and this conversion was attributed to NOy decline. Without the aerosol consideration, the model tends to overestimate HNO3 background concentration along the coast region. At the measurement site of Trinidad Head, northern California, high- concentration pollutants are usually associated with calm wind scenarios, implying that the accumulation of local pollutants leads to the high concentration. Seasonal variations are also discussed from April to May for this site. A high-resolution nesting simulation with 12-km horizontal resolution is used to study the WP-3 flight over Los Angeles and surrounding areas. This nested simulation significantly improved the predictions for emitted and secondary generated species. The difference of photochemical behavior between the coarse (60-km) and nesting simulations is discussed and compared with the observation.
AB - Regional modeling analysis for the Intercontinental Transport and Chemical Transformation 2002 (ITCT 2K2) experiment over the eastern Pacific and U.S. West Coast is performed using a multiscale modeling system, including the regional tracer model Chemical Weather Forecasting System (CFORS), the Sulfur Transport and Emissions Model 2003 (STEM-2K3) regional chemical transport model, and an off-line coupling with the Model of Ozone and Related Chemical Tracers (MOZART) global chemical transport model. CO regional tracers calculated online in the CFORS model are used to identify aircraft measurement periods with Asian influences. Asian-influenced air masses measured by the National Oceanic and Atmospheric Administration (NOAA) WP-3 aircraft in this experiment are found to have lower ΔAcetone/ΔCO, ΔMethanol /ΔCO, and ΔPropane/ ΔEthyne ratios than air masses influenced by U.S. emissions, reflecting differences in regional emission signals. The Asian air masses in the eastern Pacific are found to usually be well aged (>5 days), to be highly diffused, and to have low NOy levels. Chemical budget analysis is performed for two flights, and the O3 net chemical budgets are found to be negative (net destructive) in the places dominated by Asian influences or clear sites and positive in polluted American air masses. During the trans-Pacific transport, part of gaseous HNO3 was converted to nitrate particle, and this conversion was attributed to NOy decline. Without the aerosol consideration, the model tends to overestimate HNO3 background concentration along the coast region. At the measurement site of Trinidad Head, northern California, high- concentration pollutants are usually associated with calm wind scenarios, implying that the accumulation of local pollutants leads to the high concentration. Seasonal variations are also discussed from April to May for this site. A high-resolution nesting simulation with 12-km horizontal resolution is used to study the WP-3 flight over Los Angeles and surrounding areas. This nested simulation significantly improved the predictions for emitted and secondary generated species. The difference of photochemical behavior between the coarse (60-km) and nesting simulations is discussed and compared with the observation.
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U2 - 10.1029/2004JD004513
DO - 10.1029/2004JD004513
M3 - Article
AN - SCOPUS:20044370625
VL - 109
SP - 1
EP - 25
JO - Journal of Geophysical Research
JF - Journal of Geophysical Research
SN - 0148-0227
IS - 23
ER -