Changes in urban heat island intensity with background temperature and humidity and their associations with near-surface thermodynamic processes
Year: 2024
Type: article
Abstract: This study investigates changes in urban heat island (UHI) intensity with background temperature and humidity and their associations with physical processes. For this, we conducted idealized ensemble simulations with different initial potential temperature and water vapor mixing ratio profiles using the Weather Research and Forecasting (WRF) model. The daytime and nighttime UHI intensities increase with increasing background temperature at rates of 0.03 °C °C −1 and 0.20 °C °C −1 , respectively. The daytime and nighttime UHI intensities decrease with increasing background humidity at rates of −0.01 °C (g kg −1 ) −1 and −0.28 °C (g kg −1 ) −1 , respectively. The increase in background temperature increases the radiative cooling of rural air, enhancing the evening rural 2-m temperature decline. This also decreases the radiative heating of urban air and increases urban advective cooling, but decreases urban turbulent mixing. Consequently, the evening urban 2-m temperature decline is less enhanced, increasing the nighttime UHI intensity. The increase in background humidity decreases the radiative cooling of rural air, weakening the evening rural 2-m temperature decline. This also increases the radiative heating of urban air and decreases urban advective cooling, but increases urban turbulent mixing. Consequently, the evening urban 2-m temperature decline is less weakened, decreasing the nighttime UHI intensity.
Source: Urban Climate
Institutions: Seoul National University, Pusan National University
Language: English
Topic: Urban Heat Island Mitigation
Subfield: Environmental Engineering
Field: Environmental Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,340
Awards: G4643161432, G6554571268
OpenAlex ID: W4404092264