Journal cover Journal topic
Geoscientific Model Development An interactive open-access journal of the European Geosciences Union
doi:10.5194/gmd-2016-162
© Author(s) 2016. This work is distributed
under the Creative Commons Attribution 3.0 License.
Model description paper
05 Aug 2016
Review status
A revision of this discussion paper is under review for the journal Geoscientific Model Development (GMD).
GLEAM v3: satellite-based land evaporation and root-zone soil moisture
Brecht Martens1, Diego G. Miralles2,1, Hans Lievens1, Robin van der Schalie3,2, Richard A. M. de Jeu3, Diego Férnandez-Prieto4, Hylke E. Beck5, Wouter A. Dorigo6,1, and Niko E. C. Verhoest1 1Laboratory of Hydrology and Water Management, Ghent University, Coupure links 653, 9000 Ghent, Belgium
2Department of Earth Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1085–1087, 1081 HV Amsterdam, Netherlands
3Transmissivity/VanderSat B.V., Space Technology Center, Huygensstraat 34, 2201 DK Noordwijk, Netherlands
4European Space Research Institute (ESRIN), European Space Agency (ESA), Via Galileo Galilei 64, 00044 Frascati, Italy
5Joint Research Centre (JRC), European Comission, Via Enrico Fermi 2749, 21027 Ispra, Italy
6Department of Geodesy and Geo-Information, Vienna University of Technology, Gußhausstraße 25–29, 1040 Vienna, Austria
Abstract. The Global Land Evaporation Amsterdam Model (GLEAM) is a set of algorithms dedicated to the estimation of terrestrial evaporation and root-zone soil moisture from satellite data. Ever since its development in 2011, the model has been regularly revised aiming at the optimal incorporation of new satellite-observed geophysical variables, and improving the representation of physical processes. In this study, the next version of this model (v3) is presented. Key changes relative to the previous version include: (1) a revised formulation of the evaporative stress, (2) an optimized drainage algorithm, and (3) a new soil moisture data assimilation system. GLEAM v3 is used to produce three new data sets of terrestrial evaporation and root-zone soil moisture, including a 35-year data set spanning the period 1980–2014 (v3.0a, based on satellite-observed soil moisture, vegetation optical depth and snow water equivalents, reanalysis air temperature and radiation, and a multi-source precipitation product), and two fully satellite-based data sets. The latter two share most of their forcing, except for the vegetation optical depth and soil moisture products, which are based on observations from different passive and active C- and L-band microwave sensors (European Space Agency Climate Change Initiative data sets) for the first data set (v3.0b, spanning the period 2003–2015) and observations from the Soil Moisture and Ocean Salinity satellite in the second data set (v3.0c, spanning the period 2011–2015). These three data sets are described in detail, compared against analogous data sets generated using the previous version of GLEAM (v2), and validated against measurements from 64 eddy-covariance towers and 2338 soil moisture sensors across a broad range of ecosystems. Results indicate that the quality of the v3 soil moisture is consistently better than the one from v2: average correlations against in situ surface soil moisture measurements increase from 0.61 to 0.64 in case of the v3.0a data set and the representation of soil moisture in the second layer improves as well, with correlations increasing from 0.47 to 0.53. Similar improvements are observed for the two fully satellite-based data sets. Despite regional differences, the quality of the evaporation fluxes remains overall similar as the one obtained using the previous version of GLEAM, with average correlations against eddy-covariance measurements between 0.78 and 0.80 for the three different data sets. These global data sets of terrestrial evaporation and root-zone soil moisture are now openly available at http://GLEAM.eu and may be used for large-scale hydrological applications, climate studies and research on land-atmosphere feedbacks.

Citation: Martens, B., Miralles, D. G., Lievens, H., van der Schalie, R., de Jeu, R. A. M., Férnandez-Prieto, D., Beck, H. E., Dorigo, W. A., and Verhoest, N. E. C.: GLEAM v3: satellite-based land evaporation and root-zone soil moisture, Geosci. Model Dev. Discuss., doi:10.5194/gmd-2016-162, in review, 2016.
Brecht Martens et al.
Brecht Martens et al.
Brecht Martens et al.

Viewed

Total article views: 684 (including HTML, PDF, and XML)

HTML PDF XML Total BibTeX EndNote
445 228 11 684 9 18

Views and downloads (calculated since 05 Aug 2016)

Cumulative views and downloads (calculated since 05 Aug 2016)

Viewed (geographical distribution)

Total article views: 684 (including HTML, PDF, and XML)

Thereof 678 with geography defined and 6 with unknown origin.

Country # Views %
  • 1

Saved

Discussed

Latest update: 29 Mar 2017
Publications Copernicus
Download
Short summary
Terrestrial evaporation is a key component of the hydrological cycle and reliable datasets of this variable are of major importance. The Global Land Evaporation Amsterdam Model (GLEAM, http://GLEAM.eu) is a set of algorithms which estimates evaporation based on satellite observations. The 3rd version of GLEAM, presented in this study, includes an improved parameterization of different model components. As a result, the accuracy of the GLEAM datasets has been improved upon previous versions.
Terrestrial evaporation is a key component of the hydrological cycle and reliable datasets of...
Share