Effect of urban surface albedo on thermal environment characterization

Abstract

In order to quantify the eff ect of urbanization and land cover changes on urban surface albedo change and radiative forcing impact on urban thermal environment MODIS land surface albedo (LSA) and land surface temperature (LST) products were used to investigate the magnitude of extreme climate and anthropogenic pressures. The main goal of this study was to develop an effective remote sensing-based methodological approach to investigate the possible occurrence and associated causes of gradual surface albedo trends in metropolitan area of Bucharest during 2000-2018 period. During summer time and heat waves periods urban land surface broadband albedo is a critical variable affecting Bucharest city climate. Analysis of time series MODIS Terra/Aqua data revealed the strong inverse relationship between LSA and LST during summer time in city area with negative impact on urban thermal environment. Broadband albedo, which measures urban surface properties depends also on the atmospheric conditions. In this study, were analyzed also the interannual variations in Urban Heat Island Intensity (UHI), derived from MODIS LST data and their relationships with vegetation urban indices NDVI/EVI, climate variability and urbanization. These findings stress the dependence of urban thermal environment of urban biogeophysical variables such as land surface albedo, urban density and morphology, surface properties, vegetation, bodies of water, industrial sites, transportation systems and infrastructures.