Urban Heat Island Dynamic And Thermal Structure

Using the data of automatic weather stations (AWS)in Beijing , BECAPEX data and surface observation data of micaps, The paper synthetic diagnoses and analyses the structure of urban heat island of Beijing. At the same time, the paper simulate and test the effect of building as heat source in Beijng by non-hydrostatic version of Mesoscale numerical model MM5. by utilizing the spot data of all over the country and satellite data retrieved , more exact and more dense soil humidity data can be get by variational techniques. Through the investigation, we get the following results:1. The study presents urban heat island and valley-mountain breeze exit in Beijing, and the former is influenced by the latter, it results in the drift phenomena of the urban heat island.2. Simulate urban heat island and valley-mountain breeze in Beijing by non-hydrostatic version of Mesoscale numerical model MM5, it approves that Beijing's urban heat island actually drifts.3. Interpolating the observational high resolution build height and landuse data into the model, and think full of the effect of buildings, we can see that the building in urban affect meteorological field. The result shows that buildings in city can make heat island stronger, make wind converge in city, make relative humidity in city reduce.4. The data after variation is more exact than the satellite data and more dense than the spot data.