Remotely Sensed Soil Moisture Can Capture Dynamics Relevant to Plant Water Uptake
Name
Water Resources Research - 2023 - Feldman - Remotely Sensed Soil Moisture Can Capture Dynamics Relevant to Plant Water.pdf
Description
Published version
Size
1.41 MB
Format
Adobe PDF
Checksum (MD5)
c9a22c55e9a3bd969762f0336324c5ea
Author(s)
Feldman, Andrew F
Short Gianotti, Daniel J
Dong, Jianzhi
Akbar, Ruzbeh
Crow, Wade T
McColl, Kaighin A
Konings, Alexandra G
Nippert, Jesse B
Tumber‐Dávila, Shersingh Joseph
Holbrook, Noel M
Date Issued
January 26, 2023
Journal
Water Resources Research
Publisher
American Geophysical Union
Citation
Feldman, A. F., Short Gianotti, D. J., Dong, J., Akbar, R., Crow, W. T., McColl, K. A., et al. (2023). Remotely sensed soil moisture can capture dynamics relevant to plant water uptake. Water Resources Research, 59, e2022WR033814.
Abstract
A frequently expressed viewpoint across the Earth science community is that global soil moisture estimates from satellite L‐band (1.4 GHz) measurements represent moisture only in a shallow surface layer (0–5 cm) and consequently are of limited value for studying global terrestrial ecosystems because plants use water from deeper rootzones. Using this argumentation, many observation‐based land surface studies avoid satellite‐observed soil moisture. Here, based on peer‐reviewed literature across several fields, we argue that such a viewpoint is overly limiting for two reasons. First, microwave soil emission depth considerations and statistical considerations of vertically correlated soil moisture information together indicate that L‐band measurements carry information about soil moisture extending below the commonly referenced 5 cm in many conditions. However, spatial variations of effective depths of representation remain uncertain. Second, in reviewing isotopic tracer field studies of plant water uptake, we find a prevalence of vegetation that primarily draws moisture from these upper soil layers. This is especially true for grasslands and croplands covering more than a third of global vegetated surfaces. Even some deeper‐rooted species (i.e., shrubs and trees) preferentially or seasonally draw water from the upper soil layers. Therefore, L‐band satellite soil moisture estimates are more relevant to global vegetation water uptake than commonly appreciated (i.e., relevant beyond only shallow soil processes like soil evaporation). Our commentary encourages the application of satellite soil moisture across a broader range of terrestrial hydrosphere and biosphere studies while urging more rigorous estimates of its effective depth of representation.
MIT Department
Massachusetts Institute of Technology. Department of Civil and Environmental Engineering
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Creative Commons Attribution
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DOI of Published Version
10.1029/2022wr033814
