Assimilation of SMAP surface soil moisture retrievals into the FAO crop growth model AquaCrop v7.0
- 1KU Leuven, Earth and Environmental Sciences, Leuven, Belgium (michel.bechtold@kuleuven.be)
- 2TU Wien, Vienna, Austria
- 3NASA Goddard Space Flight Center, Greenbelt, USA
- 4KU Leuven, High Performance Computing, Leuven, Belgium
- 5Instituto de Agricultura Sostenible, Cordoba, Spain
- 6University of Cordoba, Cordoba, Spain
- 7formerly Food and Agriculture Organization of the United Nations, Rome, Italy
- 8UC Davis, USA
- 9Food and Agriculture Organization of the United Nations, Rome, Italy
Recently, the FAO crop model AquaCrop v7.0 has been released as open-source code along with the standard graphical user interface for single field applications, and Linux, Windows, and Mac stand-alone executables for plugin into regional or climate simulations (https://www.fao.org/aquacrop/en/). In addition, AquaCrop v7.0 has been coupled as the first crop model into NASA’s Land Information System (LIS) to support regional modeling and data assimilation (DA) using spatially complete re-analysis meteorological forcings, and to produce spatio-temporally complete geolocated NetCDF output for the first time. This presentation explores the potential of soil moisture updating for improving crop growth model estimates of AquaCrop.
Our DA setup uses the one-dimensional ensemble Kalman filter to assimilate the SMAP Level-2 surface soil moisture retrieval product from April 2015 through 2021 on a quarter-degree regular model grid over Europe. Prior to assimilation, a climatological rescaling is applied to remove the observation-minus-forecast bias. A preliminary evaluation against in-situ data of the International Soil Moisture Network indicates that topsoil (0-30 cm) soil moisture estimates of AquaCrop are improved through the DA compared to the model-only estimates. Our results show that the adjusted soil moisture strongly modulates biomass accumulation during the main growing period from April to June, particularly over moisture-limited areas. The impact on biomass will be further evaluated with the Copernicus Global Land Service dry matter productivity product as the observational reference.
How to cite: Bechtold, M., Busschaert, L., de Roos, S., Heyvaert, Z., Kumar, S., Mortelmans, J., Scherrer, S., Van den Bossche, M., Raes, D., Fereres, E., Garcia-Vila, M., Steduto, P., Hsiao, T., Salman, M., and De Lannoy, G.: Assimilation of SMAP surface soil moisture retrievals into the FAO crop growth model AquaCrop v7.0, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-8754, https://doi.org/10.5194/egusphere-egu23-8754, 2023.
