Validation, calibration, and improvement of remote sensing ET algorithms in mountainous regions using scintillometers /
| Main Authors: | , |
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| Format: | Government Document Software eBook |
| Language: | English |
| Published: |
Las Cruces, N.M. :
New Mexico Water Resources Research Institute, New Mexico State University,
May 2015.
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| Series: | WRRI report ;
no. 366. |
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| Abstract: | The overall goal of this study was to improve the remote sensing estimates of evapotranspiration in mountainous regions by field studies at New Mexico sites that are representative of large parts of the mountainous regions in the arid southwest. In particular, we proposed to validate sensible and latent heat fluxes estimated from the remote sensing Surface Energy Balance Algorithms for Land (SEBAL) model using large aperture scintillometer (LAS) ground measurements over mountainous landscapes in New Mexico. Unfortunately, research is not always predictable. In our study, shortly after the award of the grant we suspected and later confirmed with intercomparison measurements that the sensible heat flux measurements by the ten large aperture Kipp & Zonen scintillometers of Hendrickx's research group contained a considerable interinstrument error. Therefore, we had no choice but to shift the focus of the study toward (1) conducting a rigorous quantitative inter-comparison study for Kipp & Zonen large aperture scintillometers and (2) testing whether the biased scintillometers can still be used for field energy balance studies. Our conclusions are: (1) the first generation Kipp & Zonen LASs does indeed have a large inter-instrument bias that can exceed 21%; (2) these LASs can be used for field energy balance studies after calibration against a reference LAS or eddy covariance sensible heat flux measurements over homogeneous terrain. Our inter-comparison study by Kleissl et al. [2008] has been cited 56 times by studies reconfirming our findings or investigating error causes and remediation. More importantly the manufacturer Kipp & Zonen has redesigned its LAS and has started the production of the next generation LAS without inter-instrument biases. The New Mexico Scintillometer Network has taught us many valuable lessons on how to utilize scintillometry [Kleissl et al., 2009a] for statewide validation of evapotranspiration remote sensing algorithms in New Mexico. |
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| Item Description: | Title from PDF title page. "The research on which this report is based was financed in part by the U.S. Department of the Interior, Geological Survey (award 06HQGR0187), through the New Mexico Water Resources Research Institute (contract Q01112). Other sponsors also have contributed to this study: NSF EPSCoR grant EPS-0447691; U.S. Department of Agriculture, CSREES grant Number: 2003-35102-13654; and the NSF Science and Technology Center program Sustainability of Semi-Arid Hydrology and Riparian Areas (SAHRA; EAR-4619876800)." |
| Physical Description: | 1 CD-ROM (viii, 38 pages) : illustrations (some color), color maps ; 4 3/4 in. Also available online from WRRI, NMSU website. |
| Bibliography: | Includes bibliographical references (pages 31-38). |