@article{c7859b1d49444b369429be612450ad99,
title = "Combining the triangle method with thermal inertia to estimate regional evapotranspiration - Applied to MSG-SEVIRI data in the Senegal River basin",
abstract = "Spatially distributed estimates of evaporative fraction and actual evapotranspiration are pursued using a simple remote sensing technique based on a remotely sensed vegetation index (NDVI) and diurnal changes in land surface temperature. The technique, known as the triangle method, is improved by utilizing the high temporal resolution of the geostationary MSG-SEVIRI sensor. With 15 min acquisition intervals, the MSG-SEVIRI data allow for a precise estimation of the morning rise in land surface temperature which is a strong proxy for total daytime sensible heat fluxes. Combining the diurnal change in surface temperature, dT s with an interpretation of the triangular shaped dT s - NDVI space allows for a direct estimation of evaporative fraction. The mean daytime energy available for evapotranspiration (R n - G) is estimated using several remote sensors and limited ancillary data. Finally regional estimates of actual evapotranspiration are made by combining evaporative fraction and available energy estimates. The estimated evaporative fraction (EF) and actual evapotranspiration (ET) for the Senegal River basin have been validated against field observations for the rainy season 2005. The validation results showed low biases and RMSE and R 2 of 0.13 [-] and 0.63 for EF and RMSE of 41.45 W m - 2 and R 2 of 0.66 for ET.",
keywords = "Evaporative fraction, Evapotranspiration, MSG SEVIRI, NDVI, Remote sensing, Surface temperature, Thermal inertia, Triangle method",
author = "Simon Stisen and Inge Sandholt and Anette Norgaard and Rasmus Fensholt and Jensen, {Karsten H{\o}gh}",
note = "Funding Information: The authors would like to thank EUMETSAT for making the MSG toolbox available; Yves Govaerts and M. Clerici, both EUMETSAT for support in relation to the SEVIRI processing; CESBIO for making the SMAC code available on the Internet and Beatrice Berthelot for the sensor specific coefficients; David Taylor for making his MSG data Manager available, for his flexibility and always prompt replies; Henrik Steen Andersen, The Danish Meteorological Institute for facilitating license agreement with EUMETSAT; Mads Olander Rasmussen for the help on the MSG acquisition at the Institute of Geography; Bo Dalberg and Cheikh Mbow for setting up the instrumentation at the Dahra test site. This work contributes to the AMMA project. Based on a French initiative, AMMA was built by an international scientific group and is currently funded by a large number of agencies, especially from France, UK, US and Africa. It has been the beneficiary of a major financial contribution from the European Community's Sixth Framework Research Program. Detailed information on scientific coordination and funding is available on the AMMA International web site http://www.amma-international.org . The work was supported in part by the Danish Research Councils, ESA-related research under Grant 990249, in part by the Danish Agricultural and Veterinary Research Council under Grant 23-01-0153, and in part by the Danish Scientific Research Council under Grant 21-03-0578. All MODIS data are received through the EOS Data Gateway {\textcopyright} 2005 to the MODIS Land Discipline Group. All MSG Data {\textcopyright} 2005 to EUMETSAT. Finally the authors wish to thank an anonymous reviewer for very constructive comments and a good discussion.",
year = "2008",
month = mar,
day = "18",
doi = "10.1016/j.rse.2007.08.013",
language = "English",
volume = "112",
pages = "1242--1255",
journal = "Remote Sensing of Environment",
issn = "0034-4257",
publisher = "Elsevier",
number = "3",
}