Land Data Assimilation System (LDAS) combines multiple sources of observations (such as precipitation gauge data, satellite data, and radar precipitation measurements) to produce estimates of climatological properties at or near the Earth''s surface. This dataset is the primary (default) forcing file (File A) for Phase 2 of the North American …

This data product 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 netCDF (converted from the GRIB data files). 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. The monthly land surface forcing fields for NLDAS-2 are grouped into two files, "File A" and "File B". "File A" is the primary (default) forcing file and contains eleven meteorological forcing fields. Details about the generation of the NLDAS-2.0 forcing datasets can be found in Xia et al. (2012).

This data set contains the monthly climatology data of the primary forcing data for Phase 2 of the North American Land Data Assimilation System (NLDAS-2). The data are in 1/8th degree grid spacing. The temporal resolution is monthly, ranging from January to December. The NLDAS-2 monthly climatology data are the NLDAS-2 monthly data averaged over forty years (1981 - 2020). The file format is netCDF. The previous version of this dataset (NLDAS_MC 002) was a 30-year average and was stored in GRIB file format.A brief description about the NLDAS-2 hourly and monthly primary forcing data can be found from the NLDAS_FORA0125_H_2.0 and NLDAS_FORA0125_M_2.0 landing pages.Details about the generation of the NLDAS-2 forcing datasets can be found in Xia et al. (2012).For more information, please see the README Document.

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 monthly. The file format is WMO GRIB-1. The NLDAS-2 monthly Noah model data were generated from the NLDAS-2 hourly Noah model data, as monthly accumulation for rainfall, snowfall, subsurface runoff, surface runoff, total evapotranspiration, and snow melt, and monthly average for other variables. Monthly period of each month is from 00Z at start of the month to 23:59Z at end of the month, except the first month (Jan 1979) that starts from 00Z 02 Jan 1979. Also for the first month (Jan 1979), because the variables listed as instantaneous in the README file (http://hydro1.sci.gsfc.nasa.gov/data/s4pa/NLDAS/README.NLDAS2.pdf) do not have valid data exactly on 00Z 02 Jan 1979, and this one hour is not included in the average for this month only.

Brief description about the NLDAS-2 monthly Noah model can be found from the GCMD DIF for GES_DISC_NLDAS_NOAH0125_H_V002 at http://gcmd.gsfc.nasa.gov/getdif.htm?GES_DISC_NLDAS_NOAH0125_H_V002.

Details about the NLDAS-2 configuration of the Noah LSM can be found in Xia et al. (2012).

The NLDAS-2 Noah monthly data contain fifty-two fields. The data set applies a user-defined parameter table to indicate the contents and parameter number. The GRIBTAB file (http://disc.sci.gsfc.nasa.gov/hydrology/grib_tabs/gribtab_NLDAS_NOAH.002.txt) shows a list of parameters for this data set, along with their Product Definition Section (PDS) IDs and units.

For information about the vertical layers of the Soil Moisture Content (PDS 086), Soil Temperature (PDS 085), and Liquid Soil Moisture Content (PDS 151) please see the README Document at ftp://hydro1.sci.gsfc.nasa.gov/data/s4pa/NLDAS/README.NLDAS2.pdf or the GrADS ctl file at ftp://hydro1.sci.gsfc.nasa.gov/data/gds/NLDAS/NLDAS_NOAH0125_M.002.ctl.

The NLDAS2 forcing dataset at 1km resolution and a 1 hour time step. This dataset was used to force the conus1_baseline_85 simulation (https://hf-hydrodata.readthedocs.io/en/latest/gen_conus1_baseline_85.html). This dataset is bilinearly interpolated to the ParFlow-CONUS1 grid. The original NLDAS2 dataset can be found here (https://ldas.gsfc.nasa.gov/nldas).

This data set contains the secondary forcing hourly data "File B" 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 isnetCDF (converted from the GRIB data files).The non-precipitation land surface forcing fields for NLDAS-2 are derived from the analysis fields of the NCEP North American Regional Reanalysis (NARR). NARR analysis fields are 32-km spatial resolution and 3-hourly temporal frequency. Those NARR fields that are utilized to generate NLDAS-2 forcing fields are spatially interpolated to the finer resolution of the NLDAS 1/8th-degree grid and then temporally disaggregated to the NLDAS hourly frequency. NLDAS-2 is providing a second forcing file, "File B", in which the surface temperature, humidity, and wind fields are represented not at 2-meters and 10-meters above the height of the NLDAS terrain, but rather at the same height above the NLDAS terrain as the height above the NARR terrain of the lowest prognostic level of the NARR assimilation system (namely, the same height above the model terrain as the lowest prognostic level of the mesoscale Eta model, which is the assimilating model in NARR). The surface downward surface radiation field in "File B" is taken directly from NARR, without any bias correction. The precipitation and convective precipitation fields in "File B" are also taken directly from NARR, and are used to calculate the convective fraction provided in "File A". The aerodynamic conductance is "File B" is also taken from NARR.The hourly land surface forcing fields for NLDAS-2 are grouped into two files, "File A" and "File B". "File B" is the secondary (optional) forcing file and contains ten meteorological forcing fields. Details about the generation of the NLDAS-2 forcing datasets can be found in Xia et al. (2012).

This monthly climatology data set contains a series of land surface parameters simulated from the Mosaic 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. The temporal resolution is monthly, ranging from January to December. The NLDAS-2 monthly climatology data are the monthly data averaged over forty years (1981 - 2020). The file format is netCDF. The previous version of this dataset (NLDAS_MC 002) was a 30-year average and was stored in GRIB file format.A brief description about the NLDAS-2 hourly and monthly Mosaic LSM data can be found from the NLDAS_MOS0125_H_2.0 and NLDAS_MOS0125_M_2.0 landing pages.Details about the NLDAS-2 configuration of the Mosaic LSM can be found in Xia et al. (2012).For more information, please see the README Document.

This data set contains a series of land surface parameters simulated from the VIC 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. The temporal resolution is monthly, ranging from January to December. The NLDAS-2 monthly climatology data are the NLDAS-2 monthly data averaged over forty years (1981 - 2020). The file format is netCDF. The previous version of this dataset (NLDAS_MC 002) was a 30-year average and was stored in GRIB file format.A brief description about the NLDAS-2 hourly and monthly VIC LSM data can be found from the NLDAS_VIC0125_H_2.0 and NLDAS_VIC0125_M_2.0 landing pages.Details about the NLDAS-2 configuration of the VIC LSM can be found in Xia et al. (2012). The version of the VIC model for the NLDAS-2 VIC data available from the NASA GES DISC is VIC-4.0.3; this version of the VIC model is the same as used in Sheffield et al. (2003).For more information, please see the README Document.

This data set contains the monthly climatology (MC) data of the secondary forcing data for Phase 2 of the North American Land Data Assimilation System (NLDAS-2). The data are in 1/8th degree grid spacing. The temporal resolution is monthly, ranging from January to December. The NLDAS-2 monthly climatology data are the NLDAS-2 monthly data averaged over forty years (1981 - 2020). The file format is netCDF. The previous version of this dataset (NLDAS_MC 002) was a 30-year average and was stored in GRIB file format.A brief description about the NLDAS-2 hourly and monthly secondary forcing data can be found from the NLDAS_FORB0125_H_2.0 and NLDAS_FORB0125_M_2.0 landing pages.Details about the generation of the NLDAS-2 forcing datasets can be found in Xia et al. (2012).For more information, please see the README Document.

Le système d'assimilation des données terrestres (LDAS, Land Data Assimilation System) combine plusieurs sources d'observations (telles que les données des pluviomètres, les données satellite et les mesures radar des précipitations) pour produire des estimations des propriétés climatologiques à la surface de la Terre ou à proximité. Cet ensemble de données est le fichier de forçage principal (par défaut) (fichier A) pour la phase 2 du North American Land Data Assimilation System (NLDAS-2). Les données sont espacées d'un huitième de degré sur la grille et la résolution temporelle est d'une heure. NLDAS est un projet collaboratif entre plusieurs groupes : le Centre de modélisation environnementale (EMC) de NOAA/NCEP, le Centre de vol spatial Goddard (GSFC) de la NASA, l'université de Princeton, l'université de Washington, l'Office of Hydrological Development (OHD) de NOAA/NWS et le Centre de prévision climatique (CPC) de NOAA/NCEP. NLDAS est un projet essentiel soutenu par le programme de prédiction du climat pour les Amériques (CPPA) de la NOAA. Documentation : Readme Tutoriel Documentation GES DISC Hydrology Documentation sur les tiges de données GES DISC

This file contains the time series of monthly evapotranspiration from the 13 HUC6 basins analyzed in the North American west and southwest which accompany the article 'GRACE-FO/ECOSTRESS synergies constrain fine-scale impacts on large-scale water balance'. The evapotranspiration is from 4 different sources: NLDAS-2 (publicly available to download online from https://disc.gsfc.nasa.gov/datasets?keywords=NLDAS), ECOSTRESS (publicly available to download online from https://lpdaacsvc.cr.usgs.gov/appeears/), GRACE-based (calculated with the water balance approach (Evapotranspiration = Precipitation - Runoff - change in total water storage) using publicly available MERRA-2 precipitation (https://disc.gsfc.nasa.gov/datasets?project=MERRA-2), United States Geological Survey streamflow (https://waterdata.usgs.gov/nwis/) and GRACE total water storage anomaly data (https://podaac.jpl.nasa.gov/dataset/TELLUS_GRAC-GRFO_MASCON_CRI_GRID_RL06_V2). The MODIS evapotranspiration timeseries were obtained from a dataset created by G. Halverson (reference: Halverson, G. (2018), Near Real-Time Monitoring of Global Evapotranspiration and its Application to Water Resource Management, California State University, Northridge, Northridge, California.) The evapotranspiration data has been aggregated to monthly for all data sets. For ECOSTRESS data which is daily, the monthly aggregate was created by averaging over all available ECOSTRESS observations in each month of record. The timeseries are available from 2003 to 2019 for ET-GRACE, MODIS and NLDAS-2, and available for 2019 for ECOSTRESS. Units are in mm / day.

These tabular data sets represent the average daily soil moisture water content (kg/m^2) for four different soil layers processed from North American Land Data Assimilation System (NLDAS-2) data (Xia and others, 2012) for the period of record 1980 through 2020 and compiled for three spatial components: 1) select United States Geological Survey stream gage basins (Staub and Wieczorek, 2023), 2) individual reach flowline catchments of the Upper Colorado (ucol) portion of the Geospatial Fabric for the National Hydrologic Model, version 1.1 (nhgfv11, Bock and others, 2020 ), and 3) the upstream watersheds of each individual nhgfv11 flowline catchments. Flowline reach catchment information characterizes data at the local scale using the python tool set called gdptools (McDonald, 2021). Upstream watershed values for each reach catchment were computed using the published python software package Xstrm (Wieferich and others). The following mean daily soil moisture water content layers we ...

The NLDAS grid is a 1/8th degree grid that covers the entire contiguous US. This dataset contains the NLDAS2 forcing data at 1/8th degree resolution and a 1 hour time step. This dataset was used to force the conus1_baseline_mod simulation (https://hf-hydrodata.readthedocs.io/en/latest/gen_conus1_baseline_mod.html). This dataset is adjusted and bias corrected per the description in O'Neill et al GMD 2021 (https://gmd.copernicus.org/articles/14/7223/2021/).

This dataset contains monthly primary forcing data 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 2007 to Dec 2016. The temporal resolution is monthly.

Reference:

David Mocko, NASA/GSFC/HSL (2012), NLDAS Primary Forcing Data L4 Monthly 0.125 x 0.125 degree V002, Greenbelt, Maryland, USA, Goddard Earth Sciences Data and Information Services Center (GES DISC), Accessed: [Data Access Date], 10.5067/Z62LT6J96R4F

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.

This study evaluates the consistency between in-situ measurements and gridded datasets for precipitation and temperature within the Great Salt Lake Basin, highlighting the significant implications for hydrological modelling and climate analysis. We analysed five widely recognized gridded datasets: GRIDMET, DAYMET, PRISM, NLDAS-2, and CONUS404, utilizing statistical metrics such as the Pearson Correlation Coefficient, Root Mean Square Error (RMSE), and Kling-Gupta Efficiency to assess their accuracy and reliability against ground truth data from 30 meteorological stations. Our findings indicate that the PRISM dataset outperformed others, demonstrating the lowest median RMSE values for both precipitation (approximately 1.9 mm/day) and temperature (approximately 0.9°C), which is attributed to its advanced interpolation methods that effectively incorporate orographic adjustments. In contrast, NLDAS-2 and CONUS404, despite their finer temporal resolutions, showed greater error variability and lower performance metrics, which may limit their utility for detailed hydrological applications. Through the use of visual analytical tools such as heatmaps and boxplots, we were able to vividly illustrate the performance disparities across the datasets, thereby providing a clear comparative analysis that underscores the strengths and weaknesses of each dataset. The study emphasizes the need for careful selection of gridded datasets based on specific regional characteristics to improve the accuracy and reliability of hydro climatological studies and supports better-informed decisions in climate-related adaptations and policy-making. The insights gained from this analysis aim to guide researchers and practitioners in selecting the most appropriate datasets that align with the unique climatic and topographical conditions of the Great Salt Lake Basin, enhancing the efficacy of environmental forecasting and resource management strategies.

This monthly climatology 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. The temporal resolution is monthly, ranging from January to December. The NLDAS-2 monthly climatology data are the monthly data averaged over forty years (1981 - 2020). The file format is netCDF. The previous version of this dataset (NLDAS_MC 002) was a 30-year average and was stored in GRIB file format.A brief description about the NLDAS-2 hourly and monthly Noah LSM data can be found from the dataset landing pages for NLDAS_NOAH0125_H_2.0 and NLDAS_NOAH0125_M_2.0.Details about the NLDAS-2 configuration of the Noah LSM can be found in Xia et al. (2012).For more information, please see the README Document.

This dataset contains the 1980–2015 monthly evapotranspiration simulated by a 48-member perturbed-physics ensemble configured from the Noah LSM with multi-physics options (Noah‑MP v3.6). Simulation outputs include total evapotranspiration and its constituents (canopy evaporation, soil evaporation, and transpiration). The file name has four parts: the variable collection, the used parameterization, the time period, the suffix, and the compression format.

The 48 physics configurations are generated by combining four runoff parameterizations (run1: SIMGM, run2: SIMTOP, run3: NOAHR, run4: BATS), two parameterizations of stomatal conductance (can1: Ball–Berry, can2: Jarvis), three parameterizations of soil moisture stress factor (btr1:NOAHB, btr2: CLM, btr3: SSiB), and two parameterizations of near-surface atmospheric turbulence (tub1: M-O, tub2: Chen97).

The simulation domain covers the all of conterminous United States (25°–53°N, 125°–67°W), which is also called the NLDAS-2 testbed (Xia et al., 2012a, b). The simulations were performed at a spatial resolution of 0.125°, which is the same as for NLDAS-2 models. Details of the simulation settings and spin-up run can be found in Section 2.3 of Zheng et al. (2019) and Section 2.2 of Fei et al. (2021).

This dataset contains the 1980–2015 monthly terrestrial water budget simulated by a 48-member perturbed-physics ensemble configured from the Noah LSM with multi-physics options (Noah‑MP v3.6). Simulation outputs include total evapotranspiration and its constituents (canopy evaporation, soil evaporation, and transpiration), runoff (the surface and subsurface components), as well as terrestrial water storage (snow water equivalent, four-layer soil water content from the surface down to 2 m, and the groundwater storage anomaly). The file name has four parts: the abbreviation for "terrestrial water budget", the used parameterization, the time scale, and the suffix.

The 48 physics configurations are generated by combining four runoff parameterizations (run1: SIMGM, run2: SIMTOP, run3: NOAHR, run4: BATS), two parameterizations of stomatal conductance (can1: Ball–Berry, can2: Jarvis), three parameterizations of soil moisture stress factor (btr1:NOAHB, btr2: CLM, btr3: SSiB), and two parameterizations of near-surface atmospheric turbulence (tub1: M-O, tub2: Chen97).

The simulation domain covers the all of conterminous United States (25°–53°N, 125°–67°W), which is also called the NLDAS-2 testbed (Xia et al., 2012a, b). The simulations were performed at a spatial resolution of 0.125°, which is the same as for NLDAS-2 models. Details of the simulation settings and spin-up run can be found in Section 2.3 of Zheng et al. (2019) and Section 2.2 of Fei et al. (2021).

NWM v2.0 Pocono test case with restart and 6 months of forcing. Restart file was generated from running the model from 2017-01-01 to 2017-12-31 using NLDAS2 forcings. 6 months of NLDAS2 forcings which have been regridded are included.

This dataset contains the 1980–2015 monthly terrestrial water storage simulated by a 48-member perturbed-physics ensemble configured from the Noah LSM with multi-physics options (Noah‑MP v3.6). Simulation outputs include the total terrestrial water storage and its constituents (snow water equivalent, four-layer soil water content from the surface down to 2 m, and the groundwater storage anomaly). The file name has four parts: the variable collection, the used parameterization, the time scale, and the suffix. The 48 physics configurations are generated by combining four runoff parameterizations (run1: SIMGM, run2: SIMTOP, run3: NOAHR, run4: BATS), two parameterizations of stomatal conductance (can1: Ball–Berry, can2: Jarvis), three parameterizations of soil moisture stress factor (btr1:NOAHB, btr2: CLM, btr3: SSiB), and two parameterizations of near-surface atmospheric turbulence (tub1: M-O, tub2: Chen97). The simulation domain covers the all of conterminous United States (25°–53°N, 125°–67°W), which is also called the NLDAS-2 testbed (Xia et al., 2012a, b). The simulations were performed at a spatial resolution of 0.125°, which is the same as for NLDAS-2 models. Details of the simulation settings and spin-up run can be found in Section 2.3 of Zheng et al. (2019) and Section 2.2 of Fei et al. (2021).