Oct 7, 2015

Relationship between Evapotranspiration and Land Surface Temperature under Energy- and Water-Limited Conditions in Dry and Cold Climates

Zhigang Sun, Qinxue Wang, Ochirbat Batkhishig, and Zhu Ouyang
Advances in Meteorology
  • States remotely sensed land surface temperature- (LST-) dependent evapotranspiration (ET) models and vegetation index- (VI-) LST methods may not be suitable for ET estimation in energy-limited cold areas
  • Simulates the relationship of ET to LST using the process-based Simultaneous Heat and Water (SHAW) model for energy- and water-limited conditions in Mongolia, to understand the differences in ET processes under these two limiting conditions in dry and cold climates
  • Simulation results and ground observation data show that ET and LST have a positive relationship when air temperature () is less than or equal to the temperature () above which plants transpire and have a negative relationship when  is greater than  under the energy-limited condition
  • Finds, however, that ET and LST maintain a negative relationship with changes in  under the water-limited condition
  • States te differences in the relationship between ET and LST under the energy-limited and water-limited conditions could be attributed to plant transpiration and energy storage in moist/watered soil and plants
  • Suggests that different strategies should be used to estimate ET under the energy-limited condition in dry and cold climates