气候变化领域集成服务门户(CCPortal): Microwave implementation of two-source energy balance approach for estimating evapotranspiration

CCPortal

DOI	10.5194/hess-22-1351-2018
	Microwave implementation of two-source energy balance approach for estimating evapotranspiration
	Holmes T.R.H.; Hain C.R.; Crow W.T.; Anderson M.C.; Kustas W.P.
发表日期	2018
ISSN	1027-5606
起始页码	1351
结束页码	1369
卷号	22 期号:2
英文摘要	A newly developed microwave (MW) land surface temperature (LST) product is used to substitute thermal infrared (TIR)-based LST in the Atmosphere-Land Exchange Inverse (ALEXI) modeling framework for estimating evapotranspiration (ET) from space. ALEXI implements a two-source energy balance (TSEB) land surface scheme in a time-differential approach, designed to minimize sensitivity to absolute biases in input records of LST through the analysis of the rate of temperature change in the morning. Thermal infrared retrievals of the diurnal LST curve, traditionally from geostationary platforms, are hindered by cloud cover, reducing model coverage on any given day. This study tests the utility of diurnal temperature information retrieved from a constellation of satellites with microwave radiometers that together provide six to eight observations of Ka-band brightness temperature per location per day. This represents the first ever attempt at a global implementation of ALEXI with MW-based LST and is intended as the first step towards providing all-weather capability to the ALEXI framework. The analysis is based on 9-year-long, global records of ALEXI ET generated using both MW- and TIR-based diurnal LST information as input. In this study, the MW-LST (MW-based LST) sampling is restricted to the same clear-sky days as in the IR-based implementation to be able to analyze the impact of changing the LST dataset separately from the impact of sampling all-sky conditions. The results show that long-term bulk ET estimates from both LST sources agree well, with a spatial correlation of 92 % for total ET in the Europe-Africa domain and agreement in seasonal (3-month) totals of 83-97 % depending on the time of year. Most importantly, the ALEXI-MW (MW-based ALEXI) also matches ALEXI-IR (IR-based ALEXI) very closely in terms of 3-month inter-annual anomalies, demonstrating its ability to capture the development and extent of drought conditions. Weekly ET output from the two parallel ALEXI implementations is further compared to a common ground measured reference provided by the Fluxnet consortium. Overall, the two model implementations generate similar performance metrics (correlation and RMSE) for all but the most challenging sites in terms of spatial heterogeneity and level of aridity. It is concluded that a constellation of MW satellites can effectively be used to provide LST for estimating ET through ALEXI, which is an important step towards all-sky satellite-based retrieval of ET using an energy balance framework. © Author(s) 2018.
语种	英语
scopus关键词	Energy balance; Evapotranspiration; Geostationary satellites; Infrared radiation; Inverse problems; Microwave devices; Satellites; Surface measurement; Brightness temperatures; Constellation of satellites; Differential approach; Land surface temperature; Microwave radiometers; Model implementation; Spatial correlations; Spatial heterogeneity; Atmospheric temperature; brightness temperature; data set; energy balance; evapotranspiration; numerical model; performance assessment; satellite data; Africa; Europe
来源期刊	Hydrology and Earth System Sciences
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/160108
作者单位	Holmes, T.R.H., Hydrological Sciences Lab, NASA Goddard Space Flight Center, Greenbelt, MD 20771, United States; Hain, C.R., Earth Science Office, NASA Marshall Space Flight Center, Huntsville, AL, United States; Crow, W.T., Hydrology and Remote Sensing Laboratory, USDA ARS, Beltsville, MD 20705, United States; Anderson, M.C., Hydrology and Remote Sensing Laboratory, USDA ARS, Beltsville, MD 20705, United States; Kustas, W.P., Hydrology and Remote Sensing Laboratory, USDA ARS, Beltsville, MD 20705, United States
推荐引用方式 GB/T 7714	Holmes T.R.H.,Hain C.R.,Crow W.T.,et al. Microwave implementation of two-source energy balance approach for estimating evapotranspiration[J],2018,22(2).
APA	Holmes T.R.H.,Hain C.R.,Crow W.T.,Anderson M.C.,&Kustas W.P..(2018).Microwave implementation of two-source energy balance approach for estimating evapotranspiration.Hydrology and Earth System Sciences,22(2).
MLA	Holmes T.R.H.,et al."Microwave implementation of two-source energy balance approach for estimating evapotranspiration".Hydrology and Earth System Sciences 22.2(2018).