Open AccessReduced Urban Heat Island intensity under warmer conditions
Author(s) -
Anna A. Scott,
Darryn W. Waugh,
B. F. Zaitchik
Publication year - 2018
Publication title -
environmental research letters
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 2.37
H-Index - 124
ISSN - 1748-9326
DOI - 10.1088/1748-9326/aabd6c
Subject(s) - urban heat island , environmental science , intensity (physics) , urban climate , climatology , climate change , rural area , maximum temperature , geography , atmospheric sciences , physical geography , urbanization , meteorology , ecology , oceanography , geology , medicine , physics , pathology , quantum mechanics , biology
The Urban Heat Island (UHI), the tendency for urban areas to be hotter than rural regions, represents a significant health concern in summer as urban populations are exposed to elevated temperatures. A number of studies suggest that the UHI increases during warmer conditions, however there has been no investigation of this for a large ensemble of cities. Here we compare urban and rural temperatures in 54 US cities for 2000-2015 and show that the intensity of the urban heat island, measured here as the differences in daily-minimum or daily-maximum temperatures between urban and rural stations or Δ T , in fact tends to decrease with increasing temperature in most cities (38/54). This holds when investigating daily variability, heat extremes, and variability across climate zones and is primarily driven by changes in rural areas. We relate this change to large-scale or synoptic weather conditions, and find that the lowest Δ T nights occur during moist weather conditions. We also find that warming cities have not experienced an increasing urban heat island effect.