Knowledge of the soil moisture state is critical to our understanding of the global water and energy cycles yet routine observation is hindered by the cost of establishing appropriate sampling arrays and the high spatial variability of the soil moisture state. Passive microwave sensors aboard existing and proposed satellite platforms offer the best solution for estimating the surface soil moisture content, which can then be assimilated into land surface parameterization schemes for estimates of root zone soil moisture. One promising satellite mission planned for launch in early 2008 is the Soil Moisture and Ocean Salinity Mission (SMOS). To date, however, very few ground-based networks have been established for ongoing validation and calibration of the satellite observations. To establish appropriate soil moisture networks it is important, from a financial standpoint, that we can minimize the costs associated with validation/calibration by determining the minimum number of sites required to characterize the mean soil moisture of a satellite pixel. Using data from the SMEX 2002, SMEX 2003, and NAFE 2005 field experiments we have estimated the minimum sampling density necessary at the satellite pixel scale to characterize the mean and have used this information to establish two in situ soil moisture monitoring networks in Ontario and Saskatchewan Canada. Details of these new soil moisture observatories will also be presented.
AGU Fall Meeting Abstracts
- Pub Date:
- December 2007
- 1866 Soil moisture;
- 1895 Instruments and techniques: monitoring