Assessment of land surface temperature variation due to change in elevation of area surrounding Jaipur, India

Land surface temperature (LST) is a key parameter for surface energy balance and urban climatology studies. LST is affected by the characteristics of the land surface such as vegetation cover and its type, land use-land cover and surface imperviousness. Incessant urbanization has resulted in many fold increase in the urban area and it has caused significant changes in the land surface. The difference in altitude of two points, that are located at different parts of a vast study area, may be large. The aim of the present study is to investigate the effect of change in elevation over LST. LST data from Moderate Resolution Imaging Spectroradiometer (MODIS) and digital elevation model from ASTER have been used. Consistent inverse linear trend is observed between LST and elevation for all the study seasons. High correlation (R2=0.73–0.87) is found between elevation and mean LST. It is seen that the change in LST due to elevation difference between two points separated in space in horizontal direction varies from 3.5°C to 4.6°C per 1000m which is relatively lesser than the condition when two points are separated in vertical direction (5.0°C–10.0°C per 1000m) i.e. along a vertical column of air. The study concludes that in any study related with spatial distribution of LST over a large area, effect of change in elevation at different locations shall also be considered and LSTs at different location shall be rationalized on the basis of their comparative elevations.