Varying applicability of four different satellite-derived soil moisture products to global gridded crop model evaluation

tSatellite-derived daily surface soil moisture products have been increasingly available, but their appli-cability to global gridded crop model (GGCM) evaluation is unclear. This study compares four differentsoil moisture products with the flux tower site observation at 18 cropland sites across the world whereeither of maize, soybean, rice and wheat is grown. These products include the first and second versionsof Climate Change Initiative Soil Moisture (CCISM-1 and CCISM-2) datasets distributed by the EuropeanSpace Agency and two different AMSR-E (Advanced Microwave Scanning Radiometer–Earth ObservingSystem)-derived soil moisture datasets, separately provided by the Japan Aerospace Exploration Agency(AMSRE-J) and U.S. National Aeronautics and Space Administration (AMSRE-N). The comparison demon-strates varying reliability of these products in representing major characteristics of temporal pattern ofcropland soil moisture by product and crop. Possible reasons for the varying reliability include the differ-ences in sensors, algorithms, bands and criteria used when estimating soil moisture. Both the CCISM-1and CCISM-2 products appear the most reliable for soybean- and wheat-growing area. However, the per-centage of valid data of these products is always lower than other products due to relatively strict criteriawhen merging data derived from multiple sources, although the CCISM-2 product has much more datawith valid retrievals than the CCISM-1 product. The reliability of the AMSRE-J product is the highest formaize- and rice-growing areas and comparable to or slightly lower than the CCISM products for soybean-and wheat-growing areas. The AMSRE-N is the least reliable in most location-crop combinations. The reli-ability of the products for rice-growing area is far lower than that of other upland crops likely due to theextensive use of irrigation and patch distribution of rice paddy in the area examined here. We concludethat the CCISM-1, CCISM-2 and AMSRE-J products are applicable to GGCM evaluation, while the AMSRE-Nproduct is not. However, we encourage users to integrate these products with in situ soil moisture dataespecially when GGCMs simulations for rice are evaluated.

SAKAI Toru;  IIZUMI Toshichika;  OKADA Masashi;  NISHIMORI Motoki;  GRÜNWALD T.;  PRUEGER John;  CESCATTI Alessandro;  KORRES Wolfgang;  SCHMIDT Marius;  CARRARA Arnaud;  LOUBET B.;  CESCHIA Eric; 

2018-01-16

ELSEVIER SCIENCE BV

JRC99973

0303-2434,   

https://ac.els-cdn.com/S0303243415300349/1-s2.0-S0303243415300349-main.pdf?_tid=c953b112-fae5-11e7-bed3-00000aacb361&acdnat=1516125237_ffa7f63234af35ec37144436588e5927,    https://publications.jrc.ec.europa.eu/repository/handle/JRC99973,   

10.1016/j.jag.2015.09.011,