Publications

Wang, ZC; Pan, X; Ding, X; Guluzade, R; Yang, Z; Yuan, J; Zhou, YL; Liu, SY; Ma, WQ; Liu, YB; Yang, YB (2025). Intercomparison of temporal upscaling strategies for daily evapotranspiration estimation from the perspective of land surface temperature. JOURNAL OF HYDROLOGY, 660, 133461.

Abstract
Due to the limitations of instantaneous observations of land surface temperature (LST) using remote sensing, long-scale evapotranspiration (ET) is usually retrieved relying on temporal upscaling strategies (output/input upscaling strategy: estimation of daily ET based on instantaneous ET retrieval/temporally aggregated mean input data). In this study, those two strategies were globally evaluated under various gradients of latitude, vegetation coverage, and humidity, from the perspective of LST. Generally, the performance of the output upscaling strategy (Constant solar radiation ratio and Constant Omega method) was slightly worse than that of the input upscaling strategy (MWA and ADTC method). The output upscaling strategy should be avoided in high-latitude (possibly affected by the unavailability of the strategy) and arid regions (dominated by a large LST error contribution, -12 % measured ET), and the input upscaling strategy exhibited a larger error in low-latitude and sparsely vegetated areas where the inaccurate long-scale LST dominated with error contributions of 15 % similar to 20 % measured ET. For input upscaling strategy, the performance using LST derived from ADTC overwhelmed that of using MWA LST, especially in sparsely vegetated and arid regions. This study provided valuable insights into the selection of upscaling strategies for long-scale ET estimation around the world.

DOI:
10.1016/j.jhydrol.2025.133461

ISSN:
1879-2707