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

Abstract

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. In this study, the relationship of ET to LST was simulated 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 from the SHAW model along with ground observational data showed that ET and LST have a positive relationship when air temperature (Ta) is less than or equal to the temperature (Ttra) above which plants transpire and have a negative relationship whenTais greater thanTtraunder the energy-limited condition. However, ET and LST maintain a negative relationship with changes inTaunder the water-limited condition. The 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. This study suggests that different strategies should be used to estimate ET under the energy-limited condition in dry and cold climates.

Relations between surface temperature, albedo and evapotranspiration of melon grown with plastic mulch

“…The relationship of TS and ET was inversely proportional (Table 2), as also reported by Szilagyi (2015) and Sun et al (2016), in the latter even under energy limited and water stress conditions. The highest value of TS was recorded in the first week of the crop, just when there was the lowest ET.…”

Runoff Dynamics and Associated Multi-Scale Responses to Climate Changes in the Middle Reach of the Yarlung Zangbo River Basin, China

“…Moreover, after turning points the precipitation has a larger increasing trend than runoff, which is probably caused by continuously increasing temperature shown in Figure 7b-d; the turning points of Tavg, TNn, and TXx appear in the late 1980s. Higher temperature tends to raise the actual evapotranspiration (AET), resulting in mitigating the increasing amplitude of runoff [32]. These results reveal that the runoff variation of the MYZRB over the period 1961-2009 has a certain response to the regional climate change, but there are some differences among their turning points, which indicate that this response has a certain time lag.…”

“…The continuously increasing temperature resulted in a great rise in the AET [32] and thus lead to the increasing amplitude of runoff being less than precipitation (Figures 5 and 7a). A more important reason that increasing temperature reduced the runoff yield may be due to little snow and glacier covered in the study region.…”

Mapping Evapotranspiration Coefficients in a Temperate Maritime Climate Using the METRIC Model and Landsat TM

“…LST is a governing parameter in water and energy exchange between land and atmosphere and is also an essential input to most of the irrigation water management activities [60]. Additionally, Sun et al [61] found linear relationships between ET and LST values, while there is a strong indication that maybe there is a significant correlation even if stress conditions are prevailing over regions having maritime climatic conditions [62,63]. A linear equation was finally derived between ET r F and LST values for 17 July 2006 at this study.…”