Thermal and Geometric Controls on the Rate of Surface Air Temperature Changes in a Medium-Sized, Midlatitude CitySource: Journal of Applied Meteorology and Climatology:;2007:;volume( 046 ):;issue: 002::page 241DOI: 10.1175/JAM2486.1Publisher: American Meteorological Society
Abstract: Gradual cooling in the evening forms a wintertime nocturnal urban heat island. This work, with a mesoscale model involving urban canopy physics, is an examination of how four thermal and geometric controls?anthropogenic heat QF, heat capacity C, thermal conductivity k, and sky-view factor ?s?modify the rate of surface air temperature changes ?T/?t. In particular, the time dependence is diagnosed through numerical experiments. The controls QF and k are major agents in the evening, when QF changes the evening ?T/?t linearly and k is logarithmic. The effects of C and ?s are large in the morning and in the afternoon with those of k. The impact of QF is, however, substantial only in the evening. Because the time dependence of C and k is different, the thermal inertia used as a parameter in the urban climate studies should be divided into two parameters: C and k. To improve the thermal environment in urban areas, the modification of QF and k could be effective.
|
Collections
Show full item record
contributor author | Tomita, Tomohiko | |
contributor author | Kusaka, Hiroyuki | |
contributor author | Akiyoshi, Ryo | |
contributor author | Imasato, Yoshiyuki | |
date accessioned | 2017-06-09T16:48:12Z | |
date available | 2017-06-09T16:48:12Z | |
date copyright | 2007/02/01 | |
date issued | 2007 | |
identifier issn | 1558-8424 | |
identifier other | ams-74414.pdf | |
identifier uri | http://onlinelibrary.yabesh.ir/handle/yetl/4216637 | |
description abstract | Gradual cooling in the evening forms a wintertime nocturnal urban heat island. This work, with a mesoscale model involving urban canopy physics, is an examination of how four thermal and geometric controls?anthropogenic heat QF, heat capacity C, thermal conductivity k, and sky-view factor ?s?modify the rate of surface air temperature changes ?T/?t. In particular, the time dependence is diagnosed through numerical experiments. The controls QF and k are major agents in the evening, when QF changes the evening ?T/?t linearly and k is logarithmic. The effects of C and ?s are large in the morning and in the afternoon with those of k. The impact of QF is, however, substantial only in the evening. Because the time dependence of C and k is different, the thermal inertia used as a parameter in the urban climate studies should be divided into two parameters: C and k. To improve the thermal environment in urban areas, the modification of QF and k could be effective. | |
publisher | American Meteorological Society | |
title | Thermal and Geometric Controls on the Rate of Surface Air Temperature Changes in a Medium-Sized, Midlatitude City | |
type | Journal Paper | |
journal volume | 46 | |
journal issue | 2 | |
journal title | Journal of Applied Meteorology and Climatology | |
identifier doi | 10.1175/JAM2486.1 | |
journal fristpage | 241 | |
journal lastpage | 247 | |
tree | Journal of Applied Meteorology and Climatology:;2007:;volume( 046 ):;issue: 002 | |
contenttype | Fulltext |