Urbanized MM5 simulations of the Houston Urban Heat Island for the August 2000 Ozone Episode (MS Defense)
By Ms. Rochelle Balmori, Department of Meteorology, SJSU
ABSTRACT:
Several previous efforts have investigated impacts and benefits of urban heat island (UHI) reduction to improve urban air quality. This study simulates urban impacts for an August 2000 ozone episode in Houston by use of high-resolution morphology data and a combination of the regular (rMM5) and highly-urbanized (uMM5) versions of MM5.
Results show that on the largest domain (108 km), rMM5 captured the weak pressure gradient seen on NWS charts. On the other large domains (36, 12, and 4 km), a cold-core low, which produced an alongshore flow, was evident on the episode day. Simulations for the finest grid (1 km), by use of uMM5, show urban impacts clearly, e.g., decreased wind speed over Houston, UHIs, and UHI-induced convergence. Results showed that uMM5 simulates UHIs more accurately than rMM5. Urban reforestation scenario simulations were done to determine maximum UHI reductions and the scenario that combined the urban morphology and changes in land use/land cover data gave the maximum impact.
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