A numerical study of the nocturnal heat island over a medium-sized mid-latitude city (Columbus,Ohio)

A numerical investigation is conducted of the nocturnal heat island over Columbus, Ohio, a relatively flat mid-latitude city. Specifically, a cross-sectional steady-state numerical model to simulate the (thermal) structure of the nocturnal urban boundary layer is developed from a one-dimensional, time-dependent model due to Estoque. The model is applied to Columbus for special periods in September 1968 and March 1969 during which comparable experimental data were collected. The numerical simulations agree well with the observed data with respect to the detailed spatial form of the surface-based thermal boundary layer across the city. The use of the model for other metropolitan areas, for ascertaining the relative effect of city size and building geometry on the development of the thermal boundary layer, and for determining the effect of alternate land-use strategies on the thermal stratification are also discussed.Digest of portion of a dissertation submitted to the Pennsylvania State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy.Presented in part at the Air Pollution, Turbulence and Diffusion Symposium, Las Cruces, New Mexico, 7–10 December 1971.On assignment from the National Oceanic and Atmospheric Administration (NOAA), U.S. Department of Commerce.