Justin Sheffield's Web Pages: Current Research: NLDAS


From the LDAS web page http://ldas.gsfc.nasa.gov/: The North American LDAS system is being developed to improve reanalysis and forecast simulations by numerical weather prediction (NWP) models. Specifically, this system will reduce the errors in the stores of soil moisture and energy which are often present in NWP models and which degrade the accuracy of forecasts. NLDAS is currently running retrospectively and in near real-time on a 1/8th-degree grid. The system is currently forced by terrestrial precipitation data, space-based radiation data and numerical model output. In order to create an optimal scheme, the project involves several LSMs, many sources of data, and several institutions.

Parameter Data

The VIC model requires spatially distributed soil, vegetation and elevation parameters.

Parameter Data

To run the NLDAS version of VIC you need the following parameter data and run file
run file
soils file
snowbands file
veg file
veg library file

Publications

Sheffield, J., M. Pan, E. F. Wood, K. E. Mitchell, P. R. Houser, J. C. Schaake, A. Robock, D. Lohmann, B. A. Cosgrove, Q. Duan, L. Luo, R. W. Higgins, R. T. Pinker, J. D. Tarpley, B. H. Ramsay, Snow Process Modeling in the North American Land Data Assimilation System (NLDAS). Part I: Evaluation of Model Simulated Snow Cover Extent, 2003.

Pan, M., J. Sheffield, E. F. Wood, K. E. Mitchell, P. R. Houser, J. C. Schaake, A. Robock, D. Lohmann, B. A. Cosgrove, Q. Duan, L. Luo, R. W. Higgins, R. T. Pinker, J. D. Tarpley, Snow Process Modeling in the North American Land Data Assimilation System (NLDAS). Part II: Evaluation of Model Simulated Snow Water Equivalent, 2003.

GAPP Mississippi River Conference Abstracts

Masks

Forcings

All variables are instantaneous except for precipitation which is an accumulation

From EDAS:
1               2 Meter Temperature [k]                         11
2               2 Meter Specific Humidity [kg/kg]               51
3               Surface Pressure [Pa]                           1
4               U wind component 10m [m/s]                      33
5               V wind component 10m [m/s]                      34
6               Downward Short Wave Radiation [W/m2]            204
7               Downward Long Wave Radiation [W/m2]             205
8               Total Precipitation [kg/m2]                     61
9               Convective Precipitation [kg/m2]                63
10              Convective Avail Pot Energy (CAPE) [J/kg]       157

From GOES (Pinker)
11              Downward Short Wave Radiation [W/m2]            204
12              Skin Temperature [K]                            118
13              PAR [W/m2]                                      101

From EDAS/StageIV/Gage Combo
14              Total Precipitation [kg/m2]                     61

From StageIV
15              Total Precipitation [kg/m2]                     61

PU versus UW

Comparison between Princeton near-term retrospective (1996-1999) and UW long-term retrospective (1950-1999)

PU versus UW