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Copyright Copernicus GmbH 2012

Abstract

Soil moisture availability is important in regulating photosynthesis and controlling land surface-climate feedbacks at both the local and global scale. Recently, global remote-sensing datasets for soil moisture have become available. In this paper we assess the possibility of using remotely sensed soil moisture - AMSR-E (LPRM) - to similate soil moisture dynamics of the process-based vegetation model ORCHIDEE by evaluating the correspondence between these two products using both correlation and autocorrelation analyses. We find that the soil moisture product of AMSR-E (LPRM) and the simulated soil moisture in ORCHIDEE correlate well in space and time, in particular when considering the root zone soil moisture of ORCHIDEE. However, the root zone soil moisture in ORCHIDEE has on average a higher temporal autocorrelation relative to AMSR-E (LPRM) and in situ measurements. This may be due to the different vertical depth of the two products - AMSR-E (LPRM) at the 2-5 cm surface depth and ORCHIDEE at the root zone (max. 2 m) depth - to uncertainty in precipitation forcing in ORCHIDEE, and to the fact that the structure of ORCHIDEE consists of a single-layer deep soil, which does not allow simulation of the proper cascade of time scales that characterize soil drying after each rain event. We conclude that assimilating soil moisture, using AMSR-E (LPRM) in a land surface model like ORCHIDEE with an improved hydrological model of more than one soil layer, may significantly improve the soil moisture dynamics, which could lead to improved CO2 and energy flux predictions.

Details

Title
A global analysis of soil moisture derived from satellite observations and a land surface model
Author
Rebel, K. T.; de Jeu, R. A. M.; Ciais, P.; Viovy, N.; Piao, S. L.; Kiely, G.; Dolman, A. J.
First page
833
Publication year
2012
Publication date
2012
Publisher
Copernicus GmbH
ISSN
10275606
e-ISSN
16077938
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
968892585
Copyright
Copyright Copernicus GmbH 2012