Near-ground cooling efficacies of trees and high-albedo surfaces
- Univ. of California, Berkeley, CA (United States). Dept. of Mechanical Engineering
Daytime summer urban heat islands arise when the prevalence of dark-colored surfaces and lack of vegetation make a city warmer than neighboring countryside. Two frequently-proposed summer heat island mitigation measures are to plant trees and to increase the albedo (solar reflectivity) of ground surfaces. This dissertation examines the effects of these measures on the surface temperature of an object near the ground, and on solar heating of air near the ground. Near-ground objects include people, vehicles, and buildings. The variation of the surface temperature of a near-ground object with ground albedo indicates that a rise in ground albedo will cool a near-ground object only if the object`s albedo exceeds a critical value. This critical value of object albedo depends on wind speed, object geometry, and the height of the atmospheric thermal boundary layer. It ranges from 0.15 to 0.37 for a person. If an object has typical albedo of 0.3, increasing the ground albedo by.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 505747
- Report Number(s):
- LBNL-40334; ON: DE97007924; TRN: 97:004613
- Resource Relation:
- Other Information: TH: Thesis (Ph.D.); PBD: May 1997
- Country of Publication:
- United States
- Language:
- English
Similar Records
Meso-scale cooling effects of high albedo surfaces: Analysis of meteorological data from White Sands National Monument and White Sands Missile Range
Countermeasures to Urban Heat Islands: A Global View