Diagnostic evaluation of the transport and gas chemistry components of the STEM-II model

Abstract

The transport and gas phase chemistry components of the STEM-II model are evaluated by use of a comprehensive field data set obtained for the study of long-range pollution transport in central Japan. This data set represents a detailed description of the chemical and meteorological aspects of long-range transport under complex flow conditions. The detailed meteorological observations included surface and upper air data, and the chemical measurements included temporal and spatial distributions of NOx, O3, SOx, HNO3, and 30 hydrocarbon species. The STEM-II model, a detailed Eulerian combined transport/chemistry/deposition model, simulated one measured event that occurred during 28 and 29 July 1983. A detailed comparison of the model predictions and observations is presented for this rain free event. The STEM-II model is shown to accurately predict both the transport and chemical features. For example the surface hourly ozone predictions show a correlation coefficient of 0.9. In addition the time-averaged concentrations as well as the vertical O3 distributions are in quantitative agreement with the observations. © 1990.