NLDAS-3

The third phase of North American Land Data Assimilation System (NLDAS-3) is currently in development. We're expanding spatial coverage to all of North America and Central America, improving spatial resolution to 1-km, reducing latency, upgrading land-surface modeling, and realizing the original vision of assimilating remote sensing data for near real-time insights.

The NLDAS-3 meteorological model input (forcing) data is now publicly available. Instructions for access are provided on the NLDAS-3 GitHub README. Hourly, daily, and monthly collections are provided. Variables are listed in Table 1 below, with the daily collection also including daily-minimum and daily-maximum near-surface air temperature fields.

Please read a NASA EarthData VEDA story on the development of NLDAS-3. It includes some sample not-final precipitation data from NLDAS-3 as well as Jupyter Notebooks to examine the data and compare it to NLDAS-2 precipitation.

Please feel free to ask questions and contribute to discussions on the NLDAS-3 GitHub.

POC (Points of Contact) for NLDAS-3:

Dr. Sujay Kumar (NASA Goddard SFC): sujay.v.kumar@nasa.gov
Dr. Chris Hain (NASA Marshall SFC): christopher.hain@nasa.gov

To receive updates on NLDAS-3 datasets and workshops, please sign up using this Google Form.

Third NLDAS-3 workshop (10 April 2025):

Recording of NLDAS-3 Drought Monitoring Workshop (co-hosted with NOAA NIDIS and the National Drought Mitigation Center).

Slides presented during the 3rd NLDAS-3 workshop.

Feedback and breakout sessions slides from the 3rd NLDAS-3 workshop.

Second NLDAS-3 workshop (29 July 2024):

Recording of 2nd NLDAS-3 Stakeholder Workshop, with updates on NLDAS-3 development.

Following this workshop, we published a question/answers and discussion document on NLDAS-3.

First NLDAS-3 workshop (08 November 2023):

Recording of 1st NLDAS-3 Stakeholder Workshop.

Table 1: List of NLDAS-3 meteorological model input (forcing) variables. Data is available hourly, daily-averaged, and monthly-averaged. The daily collection also includes fields of the daily-minimum and daily-maximum near-surface air temperature.

Variable	Short Name	Units
Near-surface air temperature	Tair	K
Near-surface specific humidity	Qair	kg kg^-1
Surface pressure	PSurf	Pa
Northward wind	Wind_N	m s^-1
Eastward wind	Wind_E	m s^-1
Downward longwave radiation at the surface	LWdown	W m^-2
Downward shortwave radiation at the surface	SWdown	W m^-2
Total precipitation rate	Rainf	kg m^-2

Table 2: List of expected Noah-MP LSM output variables from NLDAS-3. Data is daily-averaged except where noted below.

Variable	Short Name	Units
Surface net downward shortwave flux	SWnet_tavg	W m^-2
Surface net downward longwave flux	LWnet_tavg	W m^-2
Surface upward latent heat flux	Qle_tavg	W m^-2
Surface upward sensible heat flux	Qh_tavg	W m^-2
Downward heat flux in soil	Qg_tavg	W m^-2
Snowfall rate (frozen)	Snowf_tavg	kg m^-2 s^-1
Rainfall rate (liquid)	Rainf_tavg	kg m^-2 s^-1
Total evapotranspiration	Evap_tavg	kg m^-2 s^-1
Surface runoff amount	Qs_tavg	kg m^-2 s^-1
Subsurface runoff amount	Qsb_tavg	kg m^-2 s^-1
Surface temperature	AvgSurfT_tavg	K
Daily minimum surface temperature	AvgSurfT_min	K
Daily maximum surface temperature	AvgSurfT_max	K
Liquid water content of surface snow	SWE_tavg	kg m^-2
Snow depth	SnowDepth_tavg	m
Soil moisture - 4 layers [0-10cm; 10-40cm; 40-100cm; 100-200cm]	SoilMoist_tavg	m³ m^-3
Soil temperature - 4 layers [0-10cm; 10-40cm; 40-100cm; 100-200cm]	SoilTemp_tavg	K
Potential evapotranspiration	PotEvap_tavg	kg m^-2 s^-1
Vapor pressure deficit	VPD_tavg	Pa
Vegetation transpiration	TVeg_tavg	kg m^-2 s^-1
Bare soil evaporation	ESoil_tavg	kg m^-2 s^-1
Total canopy water storage	CanopInt_tavg	kg m^-2
Water table depth	WaterTableD_tavg	m
Terrestrial water storage	TWS_tavg	mm
Groundwater storage	GWS_tavg	mm
Surface snow area fraction	Snowcover_tavg	[-]
Gross primary productivity	GPP_tavg	g m^-2s^-1
Net primary productivity	NPP_tavg	g m^-2 s^-1
Net ecosystem exchange	NEE_tavg	g m^-2 s^-1
Leaf area index	LAI_tavg	[-]

Table 3: List of expected HyMAP routing output variables from NLDAS-3. Data is daily-averaged.

Variable	Short Name	Units
Streamflow	Streamflow_tavg	m³ s^-1
River depth	RiverDepth_tavg	m
Flooded fraction	FloodedFrac_tavg	[-]
Surface water elevation	SurfElev_tavg	m
Surface water storage	SWS_tavg	mm

Get the Data

LDAS datasets are available from the NASA GES DISC

The NASA Goddard Earth Sciences Data and Information Services Center (GES DISC) provides access to LDAS datasets using multiple methods, including HTTPS, GDS, and the ability to subset spatially, temporally, and/or by variable:

These datasets are also available via Giovanni. Giovanni is an online application developed by the GES DISC that allows researchers to rapidly explore data, so that spatial-temporal variability, anomalous conditions, and patterns of interest can be directly and easily analyzed online before optionally downloading the data. Supported download formats include NetCDF, GeoTIFF, and KMZ.

Latest News

NLDAS-2 data re-processed from 2022-08-01 to 2024-03-01

NLDAS-2 datasets for all collections (FORA, FORB, MOS, NOAH, and VIC) were re-processed for the dates 2022-08-81 to 2024-03-01.

NLDAS-2 GRIB-1 files no longer updated as of 1 August 2024

The NLDAS Version 002 (GRIB-1) files are no longer being updated daily from the GES DISC starting from files valid at 23Z on August 1, 2024.

Reprocessed FLDAS Data

Output data for several FLDAS model runs and selected periods have been reprocessed.