NLDAS Primary Forcing Data L4 Monthly 0.125 x 0.125 degree V002 (NLDAS_FORA0125_M) at GES DISCEntry ID: GES_DISC_NLDAS_FORA0125_M_V002
Abstract: This data set contains the monthly primary forcing data "File A" for Phase 2 of the North American Land Data Assimilation System (NLDAS-2). The data are in 1/8th degree grid spacing and range from Jan 1979 to the present. The temporal resolution is monthly. The file format is WMO GRIB-1. The NLDAS-2 monthly primary forcing data were generated from the NLDAS-2 hourly primary forcing data, as ... monthly accumulation for total precipitation, convective precipitation, and potential evaporation, and monthly average for other variables. The convective precipitation monthly total is the hourly convective fraction multiplied by the hourly precipitation (both from the
NLDAS-2 "File A" files), and then summed over all hours of the month. Monthly period of each month is from 00Z at start of the month to 23:59Z at end of the month. The one exception to this is the first month (Jan. 1979) that starts from 00Z 02 Jan 1979, except for the monthly accumulated precipitation and convective precipitation that both start from 12Z 01 Jan 1979.
Brief description about the NLDAS-2 hourly primary forcing data can be found from the GCMD DIF for GES_DISC_NLDAS_FORA0125_H_V002 at http://gcmd.gsfc.nasa.gov/getdif.htm?GES_DISC_NLDAS_FORA0125_H_V002.
Details about the generation of the NLDAS-2 forcing datasets can be found in Xia et al. (2012).
The monthly land surface forcing fields for NLDAS-2 are grouped into two GRIB files, "File A" and "File B". "File A" is the primary (default) forcing file and contains eleven fields. 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.
61:APCPsfc:Precipitation monthly total [kg/m^2]
157:CAPE180_0mb:180-0 mb above ground Convective Available Potential Energy [J/kg]
153:CONVAPCPsfc:Convective precipitation monthly total [kg/m^2]
205:DLWRFsfc:Longwave radiation flux downwards (surface) [W/m^2]
204:DSWRFsfc:Shortwave radiation flux downwards (surface) [W/m^2]
228:PEVAPsfc:Potential evaporation monthly total [kg/m^2]
1:PRESsfc:Surface pressure [Pa]
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]
WGRIB or other GRIB reader is required to read the files.
For more information, please see: http://ldas.gsfc.nasa.gov/faq/#Tools
Data Set Citation
Dataset Originator/Creator: Hydrological Sciences Laboratory at NASA/Goddard Space Flight Center (GSFC/HSL)
Dataset Title: NLDAS Primary Forcing Data L4 Monthly 0.125 x 0.125 degree
Dataset Release Date: 10.01.2012
Dataset Release Place: Greenbelt, Maryland, USA
Dataset Publisher: Goddard Earth Sciences Data and Information Services Center (GES DISC)
Version: 002Online Resource: http://disc.sci.gsfc.nasa.gov/hydrology
Start Date: 1979-01-01
Latitude Resolution: 0.125 degree
Longitude Resolution: 0.125 degree
Temporal Resolution: monthly
Temporal Resolution Range: Monthly - < Annual
ATMOSPHERE > ATMOSPHERIC PRESSURE > SURFACE PRESSURE
ATMOSPHERE > ATMOSPHERIC TEMPERATURE > SURFACE AIR TEMPERATURE
ATMOSPHERE > ATMOSPHERIC WATER VAPOR > EVAPORATION
ATMOSPHERE > ATMOSPHERIC WATER VAPOR > HUMIDITY
ATMOSPHERE > ATMOSPHERIC WINDS > SURFACE WINDS
ATMOSPHERE > PRECIPITATION > RAIN
ATMOSPHERE > ATMOSPHERIC RADIATION > LONGWAVE RADIATION
ATMOSPHERE > ATMOSPHERIC RADIATION > SHORTWAVE RADIATION
ISO Topic Category
Quality The data are provisional and subject to change as model improvements are implemented and new input data sets become available.
Access Constraints None
Use Constraints None
Data Set Progress
Distribution Media: Online (HTTP)
Distribution Format: GRIB
Fees: No Fee
Role: TECHNICAL CONTACT
Email: gsfc-help-disc at lists.nasa.gov
Goddard Earth Sciences Data and Information Services Center Code 610.2 NASA Goddard Space Flight Center
Province or State: MD
Postal Code: 20771
Xia, Y., K. Mitchell, M. Ek, J. Sheffield, B. Cosgrove, E. Wood, L. Luo, C. Alonge, H. Wei, J. Meng, B. Livneh, D. Lettenmaier, V. Koren, Q. Duan, K. Mo, Y. Fan, and D. Mocko, (2012), Continental-scale water and energy flux analysis and validation for the North American Land Data Assimilation System project phase 2 (NLDAS-2): 1. Intercomparison and application of model products, J. Geophys. Res., ... 117, D03109, doi:10.1029/2011JD016048.
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.
Mahrt L., and M. Ek, 1984: The Influence of Atmospheric Stability on Potential Evaporation. J. Applied Meteorology, Vol 23, Issue 2, pp. 222–234. DOI: 10.1175/1520-0450(1984)023<0222:TIOASO>2.0.CO;2
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.
Extended Metadata Properties
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Creation and Review Dates
DIF Creation Date: 2012-08-15
Last DIF Revision Date: 2012-11-01