RT Journal Article
T1 From SMOS Soil Moisture to 3-hour Precipitation Estimates at 0.1 degrees Resolution in Africa
A1 Pellarin, Thierry
A1 Zoppis, Alexandre
A1 Román Cascón, Carlos
A1 Kerr, Yann H.
A1 Rodríguez Fernández, Nemesio
A1 Panthou, Geremy
A1 Philippon, Nathalie
A1 Cohard, Jean-Martial
AB Several recent studies have shown that knowledge of the spatiotemporal dynamics of soil moisture intrinsically contains information on precipitation. In this study, we show how SMOS measurements can be used to generate a near-real-time precipitation product with a spatial resolution of 0.1 degrees and a temporal resolution of 3 h. The principle consists of assimilating the SMOS data into a model that simulates the evolution of soil moisture, which is forced by a satellite precipitation product. The assimilation of SMOS soil moisture leads to an adjustment of the satellite precipitation rates. Using data from more than 200 rain gauges set up in Africa between 2010 and 2021, we show that the PrISM algorithm (for Precipitation Inferred from Soil Moisture) almost systematically improves the initial precipitation product. One of the original features of this study is that we used the IMERG-Early satellite precipitation product, which has a finer spatial resolution (0.1 degrees) than SMOS (~0.25 degrees). Despite this, the methodology reduces both the RMSE and bias of IMERG-Early. The RMSE is reduced from 8.0 to 6.3 mm/day, and the absolute bias is reduced from 0.81 to 0.63 mm/day on average over the 200 rain gauges. PrISM performs even slightly better on average than IMERG-Final in terms of RMSE (6.8 mm/day for IMERG-Final) but better scores are obtained by IMERG-Final in terms of absolute bias (0.35 mm/day), which utilizes a network of field measurements to correct the biases of the IMERG-Early product with a 2.5-month delay. Therefore, the use of SMOS soil moisture measurements for Africa can be an advantageous alternative to the use of gauge measurements for debiasing rainfall satellite products in real time.
PB MDPI
SN 2072-4292
YR 2022
FD 2022-02
LK https://hdl.handle.net/20.500.14352/72015
UL https://hdl.handle.net/20.500.14352/72015
LA eng
NO This research was funded by TOSCA (CNES, Centre national d'etudes spatiales, France) through the salary of A.Z during one year. The study was financially supported by ESA (grant number ESA/AO/1-7875/14/I-NC (4000114738/15/I-SBO).
NO TOSCA (CNES, Centre national d'etudes spatiales, France)
NO European Space Agency (ESA)
DS Docta Complutense
RD 9 abr 2025