Abstract
Abstract. This paper presents a comparison and an evaluation of five soil moisture products based on satellite-based passive and active microwave measurements. Products are evaluated for 2005–2006 against ground measurements obtained from the soil moisture network deployed in Mali (Sahel) in the framework of the African Monsoon Multidisciplinary Analysis project. It is shown that the accuracy of the soil moisture products is sensitive to the retrieval approach as well as to the sensor type (active or passive) and to the signal frequency (from 5.6 GHz to 18.8 GHz). The spatial patterns of surface soil moisture are compared between the different products at meso-scale (14.5° N–17.5° N and 2° W–1° W). A general good consistency between the different satellite soil moisture products is shown in terms of meso-scale spatial distribution, in particular after convective rainfall occurrences. Comparison to ground measurement shows that although soil moisture products obtained from satellite generally over-estimate soil moisture values during the dry season, most of them capture soil moisture temporal variations in good agreement with ground station measurements.
Highlights
Surface soil moisture is a key variable which controls the water and energy exchanges at the soil-vegetation-atmosphere interface. Koster et al (2004) showed that the soil moisture feedback with precipitation is very strong in the three regions of the US Great Plains, Asia and West Africa
Lowest soil moisture values from the AMSR-E/National Snow and Ice Data Center (NSIDC) product are in the range of 4% to 5.6% at the pixel scale and 2.4% at the mesoscale
This paper provides an inter-comparison and evaluation of five products derived from three different satellite sensors: four surface soil moisture and one soil moisture index which is converted to volumetric values to be comparable to the other products
Summary
Surface soil moisture is a key variable which controls the water and energy exchanges at the soil-vegetation-atmosphere interface. Koster et al (2004) showed that the soil moisture feedback with precipitation is very strong in the three regions of the US Great Plains, Asia and West Africa. Due to its high temporal and spatial variability, it is difficult to provide accurate quantitative information on soil moisture at regional and global scales. Several coordinated land surface modelling activities have provided insight into quantitative soil moisture characterisation at regional and global scale (Dirmeyer et al, 2006; Boone et al, 2009). Satellite remote sensing approaches open the possibility to provide spatially integrated information on soil moisture over large areas. Microwave remote sensing at low frequencies is the most efficient approach to characterise soil moisture from space, with low atmospheric contribution (Njoku and Entekhabi, 1996; Jones et al, 2004; Wagner et al, 2007; Kerr, 2007)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
