A novel approach in estimating surface energy balance: new perspective of urban-rural contrast in arid cities

Abstract:

Hydrological and thermal processes over the earth’s surface are essentially coupled and driven by the partitioning of available energy. The evolution of surface temperature implicitly contains the signature of energy partitioning that it can be used to diagnose the surface energy balance. Compared to land surface, energy partitioning over water surface is further complicated by the penetration and absorption of solar radiation in the water body. In this study, we developed a novel analytical method for the reconstruction of surface temperature and for the estimation of all surface energy components, by combining Green’s function approach and linear stability analysis. This new method only requires one single depth measurement of temperature or flux, and applies to the surface energy balance over either land (soil) or water continuum. Model assessment was made against in-situ measurements and numerical predications of the maximum entropy production method, indicating that this approach is robust and of good accuracy. The understanding of the surface energy balance, enabled by this new approach, has been applied to an arid city, viz. Phoenix AZ, to reveal new perspectives of different urban-rural contrasts in terms of thermal and hydrological processes.