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Description

NASA Global Land Data Assimilation System Version 2 (GLDAS-2) has three components: GLDAS-2.0, GLDAS-2.1, and GLDAS-2.2. GLDAS-2.0 is forced entirely with the Princeton meteorological forcing input data and provides a temporally consistent series from 1948 through 2014. GLDAS-2.1 is forced with a combination of model and observation data from 2000 to present. GLDAS-2.2 product suites use data assimilation (DA), whereas the GLDAS-2.0 and GLDAS-2.1 products are "open-loop" (i.e., no data assimilation). The choice of forcing data, as well as DA observation source, variable, and scheme, vary for different GLDAS-2.2 products.

This data set, GLDAS-2.0 0.25 degree daily, contains a series of land surface parameters simulated from the Catchment Land Surface Model 3.6, and currently covers from January 1948 to December 2014.

The GLDAS-2.0 model simulations were initialized on January 1, 1948, using soil moisture and other state fields from the LSM climatology for that day of the year. The simulations were forced by the global meteorological forcing data set from Princeton University (Sheffield et al., 2006). Each simulation uses the common GLDAS data sets for land water mask (MOD44W: Carroll et al., 2009) and elevation (GTOPO30) along with the model default land cover and soils datasets. Catchment model uses the Mosaic land cover classification and soils, topographic, and other model-specific parameters were derived in a consistent manner as in the NASA/GMAO’s GEOS-5 climate modeling system. The MODIS based land surface parameters are used in the current GLDAS-2.0 and GLDAS-2.1 products.

The GLDAS-2.0 data are archived and distributed in netCDF format.

Version Description

NASA Global Land Data Assimilation System Version 2 (GLDAS-2) has three components: GLDAS-2.0, GLDAS-2.1, and GLDAS-2.2. GLDAS-2.0 is forced entirely with the Princeton meteorological forcing input data and provides a temporally consistent series from 1948 through 2014. GLDAS-2.1 is forced with a combination of model and observation data from 2000 to present. GLDAS-2.2 product suites use data assimilation (DA), whereas the GLDAS-2.0 and GLDAS-2.1 products are "open-loop" (i.e., no data assimilation). The choice of forcing data, as well as DA observation source, variable, and scheme, vary for different GLDAS-2.2 products. This is the GLDAS-2.0 Catchment 0.25 degree daily data product.

Product Summary

Platforms
Catchment-LSM
Instruments
NOT APPLICABLE
Spatial Extent

N: 90 S: -60 E: 180 W: -180

Geographic Region
GLOBAL LAND
Coordinate System
CARTESIAN
Granule Spatial Representation
CARTESIAN
Temporal Extent
1948-01-01 to 2014-12-30
Data Partner
Goddard Earth Sciences Data and Information Services Center (formerly Goddard DAAC), Terrestrial Information Systems Laboratory, Earth Sciences Division, Science and Exploration Directorate, Goddard Space Flight Center, NASA (NASA/GSFC/SED/ESD/TISL/GESDI
Concept ID
C1453188197-GES_DISC
Data State
COMPLETE
Number of Files/Granules
24471
Processing Level
4
Published
Updated
Science Keywords
Surface Pressure ,
Heat Flux ,
Longwave Radiation ,
Shortwave Radiation ,
Surface Temperature ,
Humidity ,
Evapotranspiration ,
Surface Winds ,
Rain ,
Precipitation Rate ,
Snow ,
Soil Moisture/Water Content ,
Soil Temperature ,
Land Surface Temperature ,
Snow Water Equivalent ,
Runoff

Citation

Citation is critically important for dataset documentation and discovery. This dataset is openly shared, without restriction, in accordance with the EOSDIS Data Use and Citation Guidance.

Copy Citation

Li, B. (2018). GLDAS Catchment Land Surface Model L4 daily 0.25 x 0.25 degree, Version 2.0 [Data set]. NASA Goddard Earth Sciences Data and Information Services Center. https://doi.org/10.5067/LYHA9088MFWQ Date Accessed: 2025-12-12

Documents

READ-ME

GENERAL DOCUMENTATION

Variables

Variables are a set of physical properties whose values determine the characteristics or behavior of something. For example, temperature and pressure are variables of the atmosphere. Parameters and variables can be used interchangeably. Variable level attributes provide individual information for each variable.

The Name in this table is the variable name. Fill value indicates missing or undefined data points in a variable. Valid range is the range of values the variable can store. Scale factor is used to increase or decrease the size of an object and can be used to correct for distortion. For questions on a specific variable, please use the Earthdata Forum.

Name Description Units Data Type Fill Value Valid Range Scale Factor
ACond_tavg Aerodynamic conductance is a measure of how effectively vapor flows through stomata openings, total leaf area, and soil surface. Aerodynamic conductance is the inverse of aerodynamic resistance. This is a GLDAS Catchment Land Surface Model output variable, averaged over each day, measured in m s-1. m s-1 float32 -9999 N/A 1
AvgSurfT_tavg Average surface skin temperature is the temperature of the surface layer of the Earth measured at the ground level, not several meters above the surface. This is a GLDAS Catchment Land Surface Model output variable, averaged over each day, measured in K. K float32 -9999 N/A 1
CanopInt_tavg Plant canopy surface water, otherwise known as canopy interception, is the rainfall that is intercepted by the canopy of a tree and successively evaporates from the leaves. This is a GLDAS Catchment Land Surface Model output variable, averaged over each day, measured in kg m-2 (equivalent to mm). kg m-2 float32 -9999 N/A 1
ECanop_tavg Canopy water evaporation is the amount of water intercepted by the vegetation and subsequently evaporated. This is a GLDAS Catchment Land Surface Model output variable, averaged over each day, measured in kg m-2 s-1 (equivalent to mm s-1). kg m-2 s-1 float32 -9999 N/A 1
ESoil_tavg Evaporation from bare soil is the process of evaporation when it is largely independent of soil moisture content. This is a GLDAS Catchment Land Surface Model output variable, averaged over each day, measured in kg m-2 s-1 (equivalent to mm s-1). kg m-2 s-1 float32 -9999 N/A 1
EvapSnow_tavg Snow evaporation is the measure of snow changing from a solid to a gas, generally due to wind and humidity between the snow and the air. This is a GLDAS Catchment Land Surface Model output variable, averaged over each day, measured in kg m-2 s-1 (equivalent to mm s-1). kg m-2 s-1 float32 -9999 N/A 1
Evap_tavg Evapotranspiration is the combination of evaporation from the land surface and transpiration from plants. This is a GLDAS Catchment Land Surface Model output variable, averaged over each day, measured in kg m-2 s-1 (equivalent to mm s-1). kg m-2 s-1 float32 -9999 N/A 1
GWS_tavg Ground water storage is the part of precipitation that seeps down through the soil until it reaches rock material that is saturated with water, and is calculated as the remainder of terrestrial water storage after removing root zone soil moisture, snow water requivalent, and plant canopy surface water. This is a GLDAS Catchment Land Surface Model output variable, averaged over each day, measured in mm. mm float32 -9999 N/A 1
LWdown_f_tavg Downward longwave radiation flux is the component of net radiation that is downward infrared radiation from the atmosphere and clouds. This is a GLDAS Catchment Land Surface Model forcing variable, averaged over each day, measured in W m-2. W m-2 float32 -9999 N/A 1
Lwnet_tavg Net longwave radiation flux is the combination of both downward infrared radiation from the atmosphere and clouds, as well as upward emission by the underlying surface. This is a GLDAS Catchment Land Surface Model output variable, averaged over each day, measured in W m-2. W m-2 float32 -9999 N/A 1
Psurf_f_tavg Surface air pressure is the force exerted on a surface by the weight of the air above it. This is a GLDAS Catchment Land Surface Model forcing variable, averaged over each day, measured in Pa. Pa float32 -9999 N/A 1
Qair_f_tavg Specific humidity is the ratio of the mass of water vapor to the total mass of the air in an air parcel. This is a GLDAS Catchment Land Surface Model forcing variable, averaged over each day, measured in kg kg-1. kg kg-1 float32 -9999 N/A 1
Qg_tavg Ground heat flux is the transfer of energy to and from the surface. This is a GLDAS Catchment Land Surface Model output variable, averaged over each day, measured in W m-2. W m-2 float32 -9999 N/A 1
Qh_tavg Sensible heat is the energy required to change the temperature of a substance with no phase change. This is a GLDAS Catchment Land Surface Model output variable, averaged over each day, measured in W m-2. W m-2 float32 -9999 N/A 1
Qle_tavg Latent heat is the energy absorbed by or released from a substance during a change in its physical state that occurs without changing its temperature. This is a GLDAS Catchment Land Surface Model output variable, averaged over each day, measured in W m-2. W m-2 float32 -9999 N/A 1
Qsb_tavg Baseflow-groundwater runoff is the component of runoff that infiltrates the surface. This is a GLDAS Catchment Land Surface Model output variable, averaged over each day, measured in kg m-2 s-1 (equivalent to mm s-1). kg m-2 s-1 float32 -9999 N/A 1
Qsm_tavg Snow melt is the surface runoff produced from melting snow. This is a GLDAS Catchment Land Surface Model output variable, averaged over each day, measured in kg m-2 s-1 (equivalent to mm s-1). kg m-2 s-1 float32 -9999 N/A 1
Qs_tavg Storm surface runoff is the component of runoff that flows over the ground surfaces that cannot absorb the water. This is a GLDAS Catchment Land Surface Model output variable, averaged over each day, measured in kg m-2 s-1 (equivalent to mm s-1). kg m-2 s-1 float32 -9999 N/A 1
Rainf_f_tavg Total precipitation rate is a measure of intensity of both frozen and liquid precipitation over an interval of time with the assumption that the intensity was constant over that period. This is a GLDAS Catchment Land Surface Model forcing variable, averaged over each day, measured in kg m-2 s-1 (equivalent to mm s-1). kg m-2 s-1 float32 -9999 N/A 1
Rainf_tavg Rain precipitation rate is a measure of intensity of liquid precipitation over an interval of time with the assumption that the intensity was constant over that time period. This is a GLDAS Catchment Land Surface Model output variable, averaged over each day, measured in kg m-2 s-1 (equivalent to mm s-1). kg m-2 s-1 float32 -9999 N/A 1
SnowDepth_tavg Snow depth is a measure of the vertical height of frozen precipitation on the ground. This is a GLDAS Catchment Land Surface Model output variable, averaged over each day, measured in m. m float32 -9999 N/A 1
Snowf_tavg Snow precipitation rate is a measure of intensity of frozen precipitation over an interval of time with the assumption that the intensity was constant over that time period. This is a GLDAS Catchment Land Surface Model output variable, averaged over each day, measured in kg m-2 s-1 (equivalent to mm s-1). kg m-2 s-1 float32 -9999 N/A 1
SnowT_tavg Snow surface temperature is the temperature of the surface layer of snow covered ground. This is a GLDAS Catchment Land Surface Model output variable, averaged over each day, measured in K. K float32 -9999 N/A 1
SoilMoist_P_tavg Soil moisture is the water that is held in the spaces between soil particles. This is a GLDAS Catchment Land Surface Model output variable representing the full soil profile, averaged over each day, measured in kg m-2 (equivalent to mm). kg m-2 float32 -9999 N/A 1
SoilMoist_RZ_tavg Soil moisture is the water that is held in the spaces between soil particles. This is a GLDAS Catchment Land Surface Model output variable representing the root zone (0 to 100 cm below the surface), averaged over each day, measured in kg m-2 (equivalent to mm). kg m-2 float32 -9999 N/A 1
SoilMoist_S_tavg Soil moisture is the water that is held in the spaces between soil particles. This is a GLDAS Catchment Land Surface Model output variable representing the surface layer (0 to 2 cm below the surface), averaged over each day, measured in kg m-2 (equivalent to mm). kg m-2 float32 -9999 N/A 1
SWdown_f_tavg Downward shortwave radiation flux is the component of net radiation that is emitted by the sun and transmitted through the atmosphere. This is a GLDAS Catchment Land Surface Model forcing variable, averaged over each day, measured in W m-2. W m-2 float32 -9999 N/A 1
SWE_tavg Snow depth water equivalent (or SWE) is a measure of the amount of liquid water contained within the snowpack, or the depth of water that would cover the ground if the snow cover was in a liquid state. This is a GLDAS Catchment Land Surface Model output variable, averaged over each day, measured in kg m-2 (equivalent to mm). kg m-2 float32 -9999 N/A 1
Swnet_tavg Net shortwave radiation flux is the combination of the radiation emitted by the sun and transmitted through the atmosphere, and the radiation that is reflected by the underlying surface. This is a GLDAS Catchment Land Surface Model output variable, averaged over each day, measured in W m-2. W m-2 float32 -9999 N/A 1
Tair_f_tavg Air temperature is a measure of the level of kinetic energy of the atoms in the air, influenced by latitude, surface type, proximity to coast, elevation, and atmospheric and oceanic circulations. This is a GLDAS Catchment Land Surface Model forcing variable, averaged over each day, measured in K near the surface. K float32 -9999 N/A 1
TVeg_tavg Transpiration is the evaporation of water from plants, in which moisture is carried through plants from roots to small pores on the underside of leaves, where it changes to vapor and is released into the atmosphere. This is a GLDAS Catchment Land Surface Model output variable, averaged over each day, measured in kg m-2 s-1 (equivalent to mm s-1). kg m-2 s-1 float32 -9999 N/A 1
TWS_tavg Terrestrial water storage is the combination of all water on the land surface and in the subsurface, and is calculated as the sum of soil water, snow water equivalent, canopy water, and groundwater. This is a GLDAS Catchment Land Surface Model output variable, averaged over each day, measured in mm. mm float32 -9999 N/A 1
Wind_f_tavg Wind speed is measured as sustained air flow due to pressure and temperature differences. This is a GLDAS Catchment Land Surface Model forcing variable, averaged over each day, measured in m s-1. m s-1 float32 -9999 N/A 1
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