HR: 10:20h
AN: H12A-01 [Abstracts]
TI: Brightness Temperature Versus Surface Soil Moisture Assimilation
AU: Walker, J P
EM: j.walker@unimelb.edu.au
AF: University of Melbourne, Department of Civil and Environmental Engineering, Parkville, VIC 3010
Australia
AU: * Kandel, D D
EM: d.kandel@civenv.unimelb.edu.au
AF: University of Melbourne, Department of Civil and Environmental Engineering, Parkville, VIC 3010
Australia
AB:
Accurate initialisation of land surface soil moisture and temperature is crucial for improved weather and climate prediction
in coupled land-ocean-atmosphere models. Remote sensing methods provide the necessary measurements for constraining off-line
land surface model predictions to be used in coupled-model initialisation. Low frequency passive microwave is the remote
sensor of choice as it has all-weather capability with 1 to 3 day repeat coverage, and is sensitive to both near-surface soil
moisture and temperature. However, to be useful for prediction studies, deeper soil moisture and temperature must be
inferred from the near-surface observations using a data assimilation framework. The current practice of data assimilation
uses a derived near-surface soil moisture product rather than the passive microwave measurements of brightness temperatures
directly. The potential advantages for assimilating the brightness temperature are i) a capability to constrain soil
temperature in addition to soil moisture prediction, and ii) that soil temperature estimates used in deriving the soil
moisture product may be poor, yielding a poor near-surface soil moisture retrieval. However, it is currently unclear if it is
better to assimilate the derived soil moisture product or the raw brightness temperature observations. Therefore, this study
explores the potential improvement in soil moisture prediction accuracy achieved by direct assimilation of brightness
temperature data relative to a retrieved soil moisture product. This study uses C-band data from the Scanning Multifrequency
Microwave Radiometer (SMMR) and the Catchment Land Surface Model for all of Australia.
DE: 1866 Soil moisture
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting