Land Surfaces at the Tipping‐Point for Water and Energy Balance Coupling
Name
Water Resources Research - 2023 - Dong - Land Surfaces at the Tipping‐Point for Water and Energy Balance Coupling.pdf
Description
Published version
Size
3.32 MB
Format
Adobe PDF
Checksum (MD5)
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Author(s)
Dong, Jianzhi
Akbar, Ruzbeh
Feldman, Andrew F
Gianotti, Daniel Short
Entekhabi, Dara
Date Issued
February 10, 2023
Journal
Water Resources Research
Publisher
American Geophysical Union
Citation
Dong, J., Akbar, R., Feldman, A. F., Gianotti, D. S., & Entekhabi, D. (2023). Land surfaces at the tipping-point for water and energy balance coupling. Water Resources Research, 59, e2022WR032472.
Version
Final published version
Abstract
The surface water and energy balances can be coupled or uncoupled depending on whether the evaporation regime is water‐limited or energy‐limited. As the landscape loses soil moisture during drydowns, a transition between the regimes may occur, which signifies a nonlinear change in water‐energy‐carbon coupling. Regions that switch often between these two regimes, that is, are dominated by neither regime, are particularly vulnerable to climate variability and change. To robustly identify these tipping points, we identify drydown events based on global soil moisture data sets from remote sensing. The event identification does not rely on precipitation information and is robust with respect to measurement noise. Then, the soil moisture thresholds delineating the evaporation regime transitions are determined by Sequential Monte Carlo Sampling and a two‐stage parametrization strategy. Based on the estimated soil moisture thresholds across the globe, we estimate observation‐based water availability indices which quantify the nonlinear controls of soil moisture on evaporation. This framework is tested and applied globally using Soil Moisture Active Passive soil moisture retrievals. Combined with a new tippling‐point metric that describes the frequency of evaporation regime transitions, we identify regions that switch often between different evaporation regimes at the global scale. Given unit shifts in soil moisture, these regions will experience the most change in how their surface water and energy are coupled.
MIT Department
Massachusetts Institute of Technology. Department of Civil and Environmental Engineering
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
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DOI of Published Version
10.1029/2022wr032472
