Abstract:
This data set contains a series of land surface parameters simulated
from the Noah land-surface model (LSM) 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 hourly. The file format is WMO GRIB-1.
Details about the NLDAS-2 configuration of the Noah LSM can be
found
... in Xia et al. (2012).
The Noah model was developed as the land component of the NOAA NCEP
mesoscale Eta model [Betts et al. (1997); Chen et al. (1997); Ek et
al. (2003)]. As used in NLDAS-2, recent modifications were made to
Noah's cold-season [Livneh et al. (2010)] and warm-season [Wei et
al. (2012)] parameterizations. Noah serves as the land component in the
evolving Weather Research and Forecasting (WRF) regional atmospheric
model, the NOAA NCEP coupled Climate Forecast System (CFS), and the
Global Forecast System (GFS). The model simulates the soil freeze-thaw
process and its impact on soil heating/cooling and transpiration,
following Koren et al. (1999). The model has four soil layers with
spatially invariant thicknesses of 10, 30, 60, and 100 cm. The first
three layers form the root zone in non-forested regions, with the fourth
layer included in forested regions.
The Noah LSM was forced by the hourly NLDAS-2 forcing "File A" files,
and contains fifty-two 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.
PDS_IDs:Short_Name:Full_Name [Unit]
179:ACONDsfc:Aerodynamic conductance [m/s]
84:ALBDOsfc:Albedo [%]
162:ARAINsfc:Rainfall (unfrozen precipitation) [kg/m^2]
161:ASNOWsfc:Snowfall (frozen precipitation) [kg/m^2]
148:AVSFTsfc:Average surface skin temperature [K]
234:BGRUNsfc:Subsurface runoff (baseflow) [kg/m^2]
181:CCONDsfc:Canopy conductance [m/s]
223:CNWATsfc:Plant canopy surface water [kg/m^2]
205:DLWRFsfc:Longwave radiation flux downwards (surface) [W/m^2]
204:DSWRFsfc:Shortwave radiation flux downwards (surface) [W/m^2]
199:EVBSsfc:Direct evaporation from bare soil [W/m^2]
200:EVCWsfc:Canopy water evaporation [W/m^2]
57:EVPsfc:Total evapotranspiration [kg/m^2]
155:GFLUXsfc:Ground heat flux [W/m^2]
182:LAIsfc:Leaf area index (0-9) [unitless]
121:LHTFLsfc:Latent heat flux [W/m^2]
151:LSOIL0_10cm:0-10 cm liquid soil moisture content (non-frozen) [kg/m^2]
151:LSOIL10_40cm:10-40 cm liquid soil moisture content (non-frozen) [kg/m^2]
151:LSOIL40_100cm:40-100 cm liquid soil moisture content (non-frozen) [kg/m^2]
151:LSOIL100_200cm:100-200 cm liquid soil moisture content (non-frozen) [kg/m^2]
207:MSTAV0_100cm:0-100 cm Moisture availability [%]
207:MSTAV0_200cm:0-200 cm total column Moisture availability [%]
112:NLWRSsfc:Longwave radiation flux net (surface) [W/m^2]
111:NSWRSsfc:Shortwave radiation flux net (surface) [W/m^2]
145:PEVPRsfc:Potential evaporation rate [W/m^2]
248:RCQsfc:Humidity parameter in canopy conductance [fraction]
246:RCSsfc:Solar parameter in canopy conductance [fraction]
249:RCSOLsfc:Soil moisture parameter in canopy conductance [fraction]
247:RCTsfc:Temperature parameter in canopy conductance [fraction]
255:RSMACRsfc:Relative soil moisture availability control factor [0-1]
203:RSMINsfc:Minimal stomatal resistance [s/m]
250:RZSMgnd:Root zone soil moisture [kg/m^2]
198:SBSNOsfc:Sublimation (evaporation from snow) [W/m^2]
122:SHTFLsfc:Sensible heat flux [W/m^2]
66:SNODsfc:Snow depth [m]
229:SNOHFsfc:Snow phase-change heat flux [W/m^2]
99:SNOMsfc:Snow melt [kg/m^2]
238:SNOWCsfc:Snow cover [fraction]
86:SOILM0_10cm:0-10 cm layer 1 Soil moisture content [kg/m^2]
86:SOILM0_100cm:0-100 cm top 1 meter Soil moisture content [kg/m^2]
86:SOILM0_200cm:0-200 cm total column Soil moisture content [kg/m^2]
86:SOILM10_40cm:10-40 cm layer 2 Soil moisture content [kg/m^2]
86:SOILM40_100cm:40-100 cm layer 3 Soil moisture content [kg/m^2]
86:SOILM100_200cm:100-200 cm layer 4 Soil moisture content [kg/m^2]
235:SSRUNsfc:Surface runoff (non-infiltrating) [kg/m^2]
210:TRANSsfc:Transpiration [W/m^2]
85:TSOIL0_10cm:0-10 cm Soil temperature [K]
85:TSOIL10_40cm:10-40 cm Soil temperature [K]
85:TSOIL40_100cm:40-100 cm Soil temperature [K]
85:TSOIL100_200cm:100-200 cm Soil temperature [K]
87:VEGsfc:Vegetation [fraction]
65:WEASDsfc:Accumulated snow water-equivalent [kg/m^2]
WGRIB or other GRIB reader is required to read the files.
For more information, please see:
http://ldas.gsfc.nasa.gov/faq/#Tools 
