Tuesday, 11 February 2003: 4:15 PM
An Evaluation of the NOAH Land Surface Model Implemented in the Global Land Data Assimilation System
The National Center for Environmental Prediction “NOAH” land surface model (NCEP NOAH LSM) has been set up and implemented in the Global Land Data Assimilation Systems (GLDAS) at NASA Goddard Space Flight Center. At NCEP, NOAH was originally designed around certain land surface parameterizations to be used for its current operational setting and incorporation into the Eta model runs. Using these parameterizations, a one-year base-line global simulation is generated to be compared with the GLDAS version of NOAH. Without making changes to the model physics, the NOAH LSM has been modified to run on the GLDAS subgrid “tiles” at various resolutions. The GLDAS vegetation type for each tile is mapped to equivalent SIB-1 vegetation types required for NOAH. GLDAS soils are mapped to the Zobler soil classes used by NOAH. Simulations were run at a 0.5 degree resolution using both the original NOAH parameters and those derived from GLDAS standard vegetation and soils. The tiling approach was used in the GLDAS version. The two one-year simulations are forced with NCEP’s Global Data Assimilation Systems (GDAS) atmospheric model output. Various aspects of the two model runs are examined to show what major differences within the year and of different regions were affected by the changes.