Air Quality Predictions Using a Fixed Layer-Depth Vertical Structure in the Urban Airshed Model
| Autor: | Sandra L. Winkler, David P. Chock |
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| Rok vydání: | 1997 |
| Předmět: | |
| Zdroj: | Environmental Science & Technology. 31:359-370 |
| ISSN: | 1520-5851 0013-936X |
| DOI: | 10.1021/es9601292 |
| Popis: | A model with a varying layer-depth structure tends to have excessive vertical diffusion but can accommodate a well-defined mixing height. It also requires a modified vertical wind field to minimize possible local accumulation or drainage of species mass. A model with a fixed layer-depth structure may require many layers to better resolve the mixing height and contains an explicit challenge to define the thickness of the lowest layer that carries most precursor emission sources. This challenge, also present implicitly in the varying layer-depth case, could be ad dressed only if well-resolved mixing information or the eddy diffusivity profile under realistic physical environments were available, especially at night and in the morning. The impact on air quality predictions of using a fixed layer-depth and a varying layer-depth structure in the Urban Airshed Model is compared. Under the given input information and existing model assumptions, the fixed layer-depth ap proach yields substantially higher hourly c... |
| Databáze: | OpenAIRE |
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