『Abstract
The characteristics of transport and transformation of SO2, NOx and O3 in northeast
Asia have been investigated by using a comprehensive regional
air quality model (RAQM) driven by a meteorological model MM5.
A study period of 1-15 March 2002 has been selected due to the
availability of intense observation of chemical species for both
ground and upper levels. Model results have been compared against
observational data to provide insights into the strength and weakness
of the model's ability and the evolutionary features of chemical
species. Validation shows a good skill of this model system in
reproducing most of the key features in long-range transport,
but apparent bias still remains due to a series of uncertainties
from either emission estimates, prescribed parameters, or inherent
model limitations. In general, this model shows a better skill
for SO2 and O3 than
for NOx. Large discrepancy occurs between the observed and calculated
NOx concentration at higher levels, with the model results being
much lower. A series of sensitivity tests have been conducted
to investigate the potential affecting factors and it is found
that inaccuracy or incompleteness in currently used emission inventories
could be a most likely cause for such discrepancy. Long-range
transport from Asian continent to the western Pacific is pronounced
in springtime. Substantially high concentrations of SO2
and NOx in or above the boundary layer (0.5〜3.0 km) over the Yellow
Sea suggest an important pathway for long-range transport in north-east
Asia.
Keywords: numerical model; long-range transport; northeast Asia;
emission; vertical structure』
1 Introduction
2 Model description and parameters
2.1 Regional air quality model (RAQM)
2.2 Parameters used in model simulation
3 Comparison of model results with observations
3.1 Ground-level concentrations of SO2,
NOx and O3 at four monitoring sites
3.2 Vertical structure of air pollution over the Yellow Sea
4 Evolution and long-range transport of air pollutants
5 Summary and conclusions
Acknowledgements
References