Meteorological controls on daily variations of nighttime surface urban heat islands

Most previous studies of surface urban heat islands (SUHIs) have focused solely on their controlling factors a seasonal/annual timescale, while the controls daily variations are largely unknown. By extracting nighttime SUHI features using Gaussian model and investigating correlations with various explanatory factors, we attempted to determine SUHIs daily-basis over Chinese cities. Specific weather conditions intensity, extent, shape, centroid were identified. Our results show that: (1) intensity (SUHII) was considerably more sensitive than footprint (i.e., centroid). (2) Meteorological variables including relative humidity, accumulated precipitation, aerosol optical depth, had greatest impact intensity; whereas related temperature fluctuations (day-to-day air temperature) main influencing direction in which varies. (3) Antecedent precipitation substantially impacted subsequent under clear-skies, changing both itself its sensitivity other factors. Typically, clear-sky directly following rainfall showed higher dependence soil moisture aerosol, but less affected by wind. (4) The meteorological contributions SUHIIs varied among cities different bioclimatic conditions. In general, they stronger temperate zones subtropical zones. provide an improved understanding as well foundation for predicting based variables. • Surface Urban Heat Island examined. Weather contribute extent shape. affect SUHII discrepancies periods without rainfall.