Assimilating Remotely Sensed Soil Moisture in the CLM Using 1D Kalman Filter
Wenge Ni-Meister | |
Jeff Walker | |
Paul Houser | |
Extended 1-D Kalman filter (EKF) has been implemented into the catchment model and was validated using identical twin experiment in North America by Jeff Walker | |
Ensemble Kalman filter (EnKF) has been implemented into the catchchment model and was validated using identical twin experiement in North America by Rolf Reichle | |
Currently we are assimilating the soil moisture data from SMMR into the the catchement model and validate the above two data assimilation methods using in-situ measurements in Eurasia and using the new catchment definitions |
Run the catchment model without data assimilation (case I) | |
Run the catchment model with data assimilation (case II) | |
Compare modeled soil moisture from the above two cases with the in situ SM measurements | |
New catchment definitions, soil parameters, and topographic information are from Sarith Mahanama. | ||
Vegetation parameters: | ||
Use Max Suarez’s SIB vegetation types + 9 year AVHRR greenness and LAI datasets from Pierre | ||
Generate MOSAIC vegetation parameters based on the code given by Randy Koster | ||
Convert to catchment-based vegetation parameters by choosing the dominant vegetation types | ||
Compare the histograms of the land cover types both from the new and old catchment definitions to validate our algorithm | ||
Forcings: ISLSCP forcings for the period of 1987-1988 | ||
Model predictions | ||
Moisture content at the surface layer (2cm), root zone layer (1m) and the whole soil profile | ||
Period : 1987-1988 | ||
SMMR | ||
at the very thin top surface (1cm), period: 1979-87 | ||
In-situ measurements | ||
Plant-available SM: originally recorded as percent wetness by mass of dry soil->volumetric SM –> subtract volumetric SM at wilting level -> Plant-available SM | ||
Different datasets (Russia (130 stations, 1978-85, Mongolia
(42 stations, 1964-93), China (43 stations, 1981-91) cover different years |
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Three datasets with different soil moisture definitions, how will we compare them? |
Vegetation Attenuation from Polarization Ratio
Use the ECMWF forcings from Jay’s group | |
Use the new snow model | |
Reprocess the in-situ data to check the seasonality of in-situ measurements | |
Run the data assimilation | |