The Effect of Cities upon Horizontal and Vertical Temperature Gradients

Abstract

For three California cities of various sizes, two-meter-level temperature patterns were determined by intensive traverses with automobile-mounted thermistors, and vertical temperature gradients in the lowest 1000 feet were measured by wiresonde simultaneously at urban centers and peripheral open areas. In 35 evening surveys under varying weather conditions, a characteristic horizontal temperature pattern existed for each city. Temperatures increased from peripheral open lands to built-up center in direct proportion to structure density. Characteristics of the urban gradients have been analyzed in relation to city size and to meteorological parameters. Vertical temperature data showed that built-up areas frequently caused instability up to about 3 times roof height in otherwise stable air and that a “crossover” point sometimes existed above which the air over the urban center was cooler than that over surrounding country.

Temperature, urbanization and body color polymorphism in South Brazilian populations of Drosophila kikkawai (Diptera, Drosophilidae)

“…If we consider that zones of higher urbanization are considerably warmer than peripheral zones (DUCKWORTH & SANDBERG, 1954), these findings support the idea that darker phenotypes are well suceeded in low temperatures. According to BRYSON & ROSS (1972) the well-documented climatic differences between cities and their surroundings are due to a combination of the extensive road cover, less air circulation caused by buildings and air pollution, all of which contribute to turning the city into a 'thermal island'.…”

Progress in Urban Meteorology :A Review

“…Field experiments on urban boundary layers have revealed fundamental characteristics of the mesoscale UHI structure; typical nocturnal temperature profiles including elevated inversions and the crossover phenomena (Duckworth and Sandberg 1954;Bornstein 1968;Clarke 1969;Oke and East 1971), surface wind convergence in the UHI (Schreffler 1978(Schreffler , 1979a(Schreffler , 1979b, and turbulent profiles (Hildebrand and Ackerman 1984;Clarke et al 1982;Uno et al 1988). Oke (1974Oke ( , 1979aOke ( , 1987 gives a comprehensive review of the early observational studies.…”

Cooling our communities: A guidebook on tree planting and light-colored surfacing

“…Oke (1978). The technical papers by Oke (1975Oke ( , 1987, and Duckworth and Sandberg (1954) dot',tribe measurements of heat island intensities. The paper by Myrup ""'" (1969) describes a simple computer analysis of the urban heat island, The proceedings from the Urban Climatology Workshop in Mexico City (Oke, 1986) has numerous articles by Oke, Landsberg, and others on urban heat islands in tropical cities.…”