气候变化领域集成服务门户(CCPortal): Using SMAP Level-4 soil moisture to constrain MOD16 evapotranspiration over the contiguous USA

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DOI	10.1016/j.rse.2020.112277
	Using SMAP Level-4 soil moisture to constrain MOD16 evapotranspiration over the contiguous USA
	Brust C.; Kimball J.S.; Maneta M.P.; Jencso K.; He M.; Reichle R.H.
发表日期	2021
ISSN	00344257
卷号	255
英文摘要	Evapotranspiration (ET) is a key hydrologic variable linking the Earth's water, carbon and energy cycles. At large spatial scales, remote sensing-based (RS) models are often used to quantify ET. Despite the large number of RS ET models available, few include soil moisture as a key environmental input, which can degrade model accuracy and utility. Here, we use model assimilation enhanced soil moisture estimates from the NASA SMAP (Soil Moisture Active Passive) mission as a water supply control in the MOD16 ET algorithm framework. SMAP-derived daily surface (0-5 cm depth) and root zone (0-1 m depth) soil moisture are used with MODIS (Moderate Resolution Imaging Spectroradiometer) vegetation observations, and 4 km gridded regional surface meteorology (Gridmet) as primary inputs for estimating daily ET and underlying model soil and stomatal conductance terms. We calibrated the model environmental response parameters using tower eddy covariance ET observations representing major North American biomes. The model ET results were validated using a holdout set of tower observations spanning a large regional climate gradient. The updated ET estimates outperform the baseline MOD16 product across all tower validation sites (RMSE = 0.758 vs 1.108 mm day−1; R2 = 0.68 vs 0.45, respectively). Smaller relative improvements were obtained using a recalibrated model with 4 km Gridmet meteorology, but no soil moisture control (RMSE = 0.813 mm day−1; R2 = 0.66), indicating that these changes are essential for the improved model performance. The soil moisture-constrained model improvements and relative benefits from the SMAP observations are greater in arid climates, consistent with stronger soil moisture control on ET in water-limited regions. The use of SMAP soil moisture as an additional model constraint improves MOD16 regional performance and provides a new framework for investigating both soil and atmosphere controls on ET. © 2020 Elsevier Inc.
英文关键词	Evapotranspiration; MOD16; MODIS; SMAP; Soil moisture
语种	英语
scopus关键词	Climate models; Evapotranspiration; Meteorology; Moisture control; NASA; Radiometers; Remote sensing; Water supply; Algorithm framework; Atmosphere controls; Constrained models; Environmental response; Model performance; Moderate resolution imaging spectroradiometer; Stomatal conductance; Water-limited regions; Soil moisture
来源期刊	Remote Sensing of Environment
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/178968
作者单位	Numerical Terradynamic Simulation Group, W.A. Franke College of Forestry & Conservation, University of Montana, Missoula, MT 59812, United States; Department of Geosciences, University of Montana, Missoula, MT 59812, United States; Montana Climate Office, W.A. Franke College of Forestry & Conservation, University of Montana, Missoula, MT 59812, United States; Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing, 10087, China; Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD 20771, United States
推荐引用方式 GB/T 7714	Brust C.,Kimball J.S.,Maneta M.P.,et al. Using SMAP Level-4 soil moisture to constrain MOD16 evapotranspiration over the contiguous USA[J],2021,255.
APA	Brust C.,Kimball J.S.,Maneta M.P.,Jencso K.,He M.,&Reichle R.H..(2021).Using SMAP Level-4 soil moisture to constrain MOD16 evapotranspiration over the contiguous USA.Remote Sensing of Environment,255.
MLA	Brust C.,et al."Using SMAP Level-4 soil moisture to constrain MOD16 evapotranspiration over the contiguous USA".Remote Sensing of Environment 255(2021).