Temperature-land cover interactions: The inversion of urban heat island phenomenon in desert city areas

Remote sensing data from MODIS, ASTER and LANDSAT 7 sensors were used to assess land cover-temperature interactions in the Abu Dhabi metropolitan area over a 10-year period between 2000 and 2010 with a multi-sensor approach. Low resolution data from MODIS sensor with high revisiting time have been used to analyze the daily variation of Land Surface Temperature (LST), the derived Surface Urban Heat Island (SUHI), and the Normalized Difference Vegetation Index (NDVI) at city level. Medium resolution data from ASTER and LANDSAT 7 sensors have been used for spot assessment of the above mentioned parameters at district level. With medium resolution satellites, LST and NDVI have been analyzed in correspondence of different level of Impervious Surface Areas (ISAs) over the study period. With both datasets, the obtained results showed an inversion of the standard SUHI phenomenon during daytime, where the downtown areas appear colder compared to the suburbs. Throughout the study period, the trend has been replicated and seasonality is also observed, where the inversion of SUHI is accentuated mainly in the summer months with a daily difference of 5-6 K compared to 2-3 K during the winter season, while the standard SUHI can be observed during the night with values of downtown 2-3 K higher than the suburbs. Spot analysis of single images confirmed this trend, adding the contribution of ISA to an average increment of 1 K during winter and 2 K during the summer. (C) 2012 Elsevier Inc. All rights reserved.