Publication Type

Journal Article

Version

publishedVersion

Publication Date

9-2011

Abstract

Urbanization affects near-surface climates by increasing city temperatures relative to rural temperatures [i.e., the urban heat island (UHI) effect]. This effect is usually measured as the relative temperature difference between urban areas and a rural location. Use of this measure is potentially problematic, however, mainly because of unclear ‘‘rural’’ definitions across different cities. An alternative metric is proposed—surface temperature cooling/warming rates—that directly measures how variations in land-use and land cover (LULC) affect temperatures for a specific urban area. In this study, the impact of local-scale (,1 km2 ), historical LULC change was examined on near-surface nocturnal meteorological station temperatures sited within metropolitan Phoenix, Arizona, for 1) urban versus rural areas, 2) areas that underwent rural-to-urban transition over a 20-yr period, and 3) different seasons. Temperature data were analyzed during ideal synoptic conditions of clear and calm weather that do not inhibit surface cooling and that also qualified with respect to measured near-surface wind impacts. Results indicated that 1) urban areas generally observed lower coolingrate magnitudes than did rural areas, 2) urbanization significantly reduced cooling rates over time, and 3) mean cooling-rate magnitudes were typically larger in summer than in winter. Significant variations in mean nocturnal urban wind speeds were also observed over time, suggesting a possible UHI-induced circulation system that may have influenced local-scale station cooling rates.

Discipline

Environmental Sciences | Urban Studies and Planning

Research Areas

Political Science

Publication

Journal of Applied Meteorology and Climatology

Volume

50

Issue

9

First Page

1872

Last Page

1883

ISSN

1558-8432

Identifier

10.1175/JAMC-D-10-05014.1

Publisher

American Meteorological Society

Additional URL

https://doi.org/10.1175/JAMC-D-10-05014.1

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