NLDAS Forcing Data L4 Monthly 0.125 x 0.125 degree V001 (NLDAS_FOR0125_M) at GES DISC
This data set contains the forcing data for Phase 1 of the North American Land Data Assimilation System (NLDAS-1). The data are in 1/8th degree grid spacing and range from Aug. 1996 to Dec. 2007. The temporal resolution is monthly. The file format is WMO GRIB-1. The NLDAS-1 monthly forcing data, containing 17 variables, were generated from the NLDAS-1 hourly forcing data. More information about ... how monthly data were generated can be found from below the variable list.
Brief description about the NLDAS-1 hourly forcing data can be found from the GCMD DIF for GES_DISC_NLDAS_FOR0125_H_V001 at http://gcmd.gsfc.nasa.gov/getdif.htm?GES_DISC_NLDAS_FOR0125_H_V001.
The data set applies a user-defined parameter table to indicate the contents and parameter number. The following table shows a list of parameters, their Product Definition Section (PDS) IDs and units.
63:ACPCPsfc:Convective precipitation monthly total from EDAS [kg/m^2]
153:CONVAPCPsfc:Convective precipitation monthly total [kg/m^2]
61:APCPsfc:Precipitation monthly total [kg/m^2]
118:BRTMPsfc:Surface brightness temperature from GOES-UMD Pinker [K]
157:CAPEsfc:Convective Available Potential Energy [J/kg]
205:DLWRFsfc:Longwave radiation flux downwards (surface) [W/m^2]
204:DSWRFsfc:Shortwave radiation flux downwards (surface) [W/m^2]
101:PARsfc:PAR Photosynthetically Active Radiation from GOES-UMD Pinker [W/m^2]
201:PEDASsfc:Precipitation monthly total from EDAS [kg/m^2]
202:PRDARsfc:Precipitation monthly total from StageII [kg/m^2]
1:PRESsfc:Surface pressure [Pa]
206:RGOESsfc:Shortwave radiation flux downwards (surface) from GOES-UMD Pinker [W/m^2]
51:SPFH2m:2-m above ground Specific humidity [kg/kg]
11:TMP2m:2-m above ground Temperature [K]
33:UGRD10m:10-m above ground Zonal wind speed [m/s]
34:VGRD10m:10-m above ground Meridional wind speed [m/s]
209:RSWRFsfc:Shortwave radiation flux downwards (surface) blended from EDAS and GOES-UMD Pinker [W/m^2]
The variables, DLWRFsfc, DSWRFsfc, PRESsfc, SPFH2m, TMP2m, UGRD10m, and VGRD10m, are the monthly average from 00Z01 of month to 23:59Zlastdayofmonth.
The variables, BRTMPsfc and CAPEsfc, are the monthly average from 00Z01 of month to 23:59Zlastdayofmonth, except if any hour has an undefined value of -9999, then do not include the hour in the monthly average.
The variables, PARsfc and RGOESsfc, are the monthly average from 00Z01 of month to 23:59Zlastdayofmonth, except if any hour has an undefined value of -9999, then reassign the variable as zero and include the hour in the monthly average.
The variables, ACPCPsfc, APCPsfc, PEDASsfc, and PRDARsfc, are the monthly accumulation from 00Z01 of month to 23:59Zlastdayofmonth. However, the ACPCPsfc is actually the sum of the (ACPCPsfc/PEDASsfc)*APCPsfc from each hour, where the ratio of (ACPCPsfc/PEDASsfc) is the fraction of convective precipitation from EDAS, and then multiplied by the APCPsfc to get the convective precipitation. For PRDARsfc accumulation, if hourly PRDARsfc is undefined or negative, fill the hour with a zero value.
The last variable, RSWRFsfc, is the monthly average from 00Z01 of month to 23:59Zlastdayofmonth, except represents the monthly average of the hourly "blend" of the DSWRFsfc from EDAS and RGOESsfc from GEOS. The blend algorithm is that, for each hour, the RGOESsfc from GEOS is used for all the grid points where it is available, but for where it is not available, the DSWRFsfc from EDAS is used. Because the spatial extent/availability of GEOS varies from hour to hour, this blend is done for hourly data first, and then the monthly average is applied to the hourly blended data. This last variable thus best represents the shortwave radiation flux downwards at the surface that is used in the NLDAS-1 LSMs. More about this blending/supplementation can be found from http://ldas.gsfc.nasa.gov/nldas/NLDAS1forcing.php.
WGRIB or other GRIB reader is required to read the files.
For more information, please see: http://ldas.gsfc.nasa.gov/faq/#Tools
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Precipitation monthly total
NLDAS-1 Forcing monthly 0.125 degree \ Precipitation monthly total August 1996 [kg/m^2]
Data Set Citation
Hydrological Sciences Laboratory at NASA/Goddard Space Flight Center (GSFC/HSL)
NLDAS Forcing Data L4 Monthly 0.125 x 0.125 degree
Dataset Release Date:
Dataset Release Place:
Greenbelt, Maryland, USA
Goddard Earth Sciences Data and Information Services Center (GES DISC)
The data are provisional and subject to change as model improvements are implemented and new input data sets become available.
Data Set Progress
gsfc-help-disc at lists.nasa.gov
Goddard Earth Sciences Data and Information Services Center
NASA Goddard Space Flight Center
Province or State:
Cosgrove, B. A., D. Lohmann, K. E. Mitchell, P. R. Houser, E. F. Wood, J. Schaake, A. Robock, C. Marshall, J. Sheffield, L. Luo, Q. Duan, R. T. Pinker, J. D. Tarpley, R. W. Higgins, and J. Meng (2003), Real-time and retrospective forcing in the North American Land Data Assimilation System (NLDAS) project, J. Geophys. Res., 108(D22), 8842, doi:10.1029/2002JD003118.
Higgins, ... R. W., W. Shi, E. Yarosh, and R. Joyce (2000), Improved United States precipitation quality control system and analysis, NCEP/Clim. Predict. Cent. Atlas 7, Clim. Predict. Cent., Camp Springs, Md.
Pinker, R. T., J. D. Tarpley, I. Laszlo, K. E. Mitchell, P. R. Houser, E. F. Wood, J. C. Schaake, A. Robock, D. Lohmann, B. A. Cosgrove, J. Sheffield, Q. Duan, L. Luo, and R. W. Higgins (2003), Surface radiation budgets in support of the GEWEX Continental-Scale International Project (GCIP) and the GEWEX Americas Prediction Project (GAPP), including the North American Land Data Assimilation System (NLDAS) project, J. Geophys. Res., 108(D22), 8844, doi:10.1029/2002JD003301.
Rogers, E., D. Deaven and G. J. DiMego, 1995: The regional analysis system for the operational "early" Eta model: original 80-km configuration and recent changes. Wea. Forecasting, 10, 810-825.
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Creation and Review Dates
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