Soil moisture profiles of ecosystem water use revealed with ECOSTRESS

While remote sensing has provided extensive insights into the global terrestrial water, carbon, and energy cycles, space-based retrievals remain limited in observing the belowground influence of the full soil moisture profile on ecosystem function. We show that this gap can be addressed when coupling 70m resolution ECOSTRESS retrievals of land surface temperature (LST) with in-situ soil moisture profile measurements. These datasets together reveal that ecosystem water use progressively decreases with depth with 93% of sites showing LST coupling with soil moisture shallower than 20cm while 34% have interactions with soil moisture deeper than 50cm. Furthermore, the median depth of peak ecosystem water use is estimated to be 10cm, though forests have more common peak interactions with deeper soil layers (50-100cm) in 37% of cases. High spatial resolution remote sensing coupled with field-level data can thus elucidate the role of belowground processes on land surface behavior.