FLDAS¶

FEWS NET Land Data Assimilation System (FLDAS — NASA land modelling system for the Famine Early Warning Systems Network; global 0.1° monthly and Central Asia 0.01° daily)

Available

At a glance¶

Note on period: The global final version (FLDAS_NOAH01_C_GL_M) and the anomalies (MA) start in 1982-01, the preliminary version (FLDAS_NOAH01_CP_GL_M) in 2019-01, and the monthly climatology (MC) averages 1982–2016. The Central Asia daily product (FLDAS_NOAHMP001_G_CA_D) starts on 2000-10-01. On 2026-10-13 the data extended to 2026-08 (final), 2026-09 (preliminary) and 2026-10-11 (Central Asia daily).

Overview¶

FLDAS is a land surface modelling system that NASA GSFC runs with its Land Information System (LIS) for the USAID-funded Famine Early Warning Systems Network (FEWS NET). It produces soil moisture, evapotranspiration, runoff and snow to support food and water security decisions in data-sparse developing countries. The main public product is a global 0.1° monthly record from 1982, made by driving Noah 3.6.1 with CHIRPS precipitation and MERRA-2 (final) or GDAS (preliminary) meteorology; Central Asia, including Afghanistan, has a 0.01° daily product from Noah-MP 4.0.1. Despite the name, the public products are open-loop simulations without data assimilation.

What changes with the successor¶

FLDAS Central Asia Noah 3.6 daily (FLDAS_NOAH001_G_CA_D) → FLDAS2 Central Asia Noah-MP daily (FLDAS_NOAHMP001_G_CA_D)¶

Transition: 2023-10

An FLDAS2 product rebuilt with Noah-MP 4.0.1 over the same domain, resolution and period (2000-10 onward) was released in November 2023; the Noah 3.6 daily product stopped updating on 1 October 2023 and was announced for decommissioning in March 2024. On 2026-10-13 the Noah 3.6 collection no longer appears in NASA CMR.

Sources: NASA LDAS — FLDAS Central Asia · README for FLDAS2 Noah-MP Central Asia

FLDAS Africa regional products (East, Southern, West Africa) → FLDAS global product (0.1° monthly)¶

Transition: 2019-11

The separate East, Southern and West Africa monthly and daily products were retired in September–November 2019 and replaced by a quasi-global monthly product with the same Noah 0.1° configuration.

Sources: README for FLDAS

Available variables¶

Main variables from the GES DISC README tables (Tables 5a and 5c; FLDAS2 Table 6). Names are the netCDF variable names; variables with _f are forcing, not model output. Some README entries differ between tables (e.g. the unit of Qs_tavg, or Snowcover_inst capitalisation in the Central Asia product), so check them in a downloaded file.

instantaneous mean accumulated maximum minimum static — instantaneous: value at the time stamp · mean/accumulated/maximum/minimum: over the indicated interval · static: does not change with time

Water fluxes (global monthly, monthly mean rates)¶

Energy fluxes and surface (global monthly)¶

Soil (global monthly, 4 layers)¶

Snow (global monthly, instantaneous)¶

Forcing (global monthly, monthly means)¶

Central Asia Noah-MP daily (FLDAS_NOAHMP001_G_CA_D)¶

Monthly anomalies and climatology (FLDAS_NOAH01_C_GL_MA, MC)¶

The full variable list is in the official documentation.

How to get the data¶

• NASA GES DISC — FLDAS dataset list — HTTPS download / earthaccess / Earthdata Search / OPeNDAP / subsetting
  • Global final FLDAS_NOAH01_C_GL_M, preliminary FLDAS_NOAH01_CP_GL_M, anomalies FLDAS_NOAH01_C_GL_MA, climatology FLDAS_NOAH01_C_GL_MC, and Central Asia daily FLDAS_NOAHMP001_G_CA_D, all version 001. A free Earthdata Login is required. The old server (hydro1.gesdisc.eosdis.nasa.gov) may close after 30 September 2026, so switch to data.gesdisc.earthdata.nasa.gov or earthaccess.
• AWS us-west-2 direct access (S3) — Cloud storage (S3, in-region us-west-2 only)
  • Example: s3://gesdisc-cumulus-prod-protected/FLDAS/FLDAS_NOAH01_C_GL_M.001/ — temporary credentials are required.
• NASA Giovanni — Web maps and time series; NetCDF, GeoTIFF and KMZ downloads
  • Lets you check area-mean time series and anomaly maps before downloading.
• NASA LDAS — FLDAS model descriptions — Documentation and maps
  • Describes the Global, Central Asia and Forecast systems and their parameter data. The 0.25° Africa and Middle East forecasts are available on request, not from a public archive.

Example code¶

Uses earthaccess to download the 2024 global final monthly files and compute monthly precipitation and evapotranspiration (mm) over Korea. You will be asked for your Earthdata credentials on the first run. Check the coordinate names in the downloaded file (lon and lat are assumed below).

import earthaccess
import xarray as xr

earthaccess.login()  # free NASA Earthdata account
results = earthaccess.search_data(
    short_name="FLDAS_NOAH01_C_GL_M", version="001",
    temporal=("2024-01-01", "2024-12-31"),
    bounding_box=(124, 33, 132, 39),   # (west, south, east, north)
)
files = earthaccess.download(results, "fldas_global_monthly")

ds = xr.open_mfdataset(files, combine="by_coords")
print(ds)                                   # check coordinate and variable names
sub = ds.sel(lon=slice(124, 132), lat=slice(33, 39))
days = sub["time"].dt.days_in_month

precip_mm = sub["Rainf_f_tavg"] * 86400 * days   # monthly mean rate (kg m-2 s-1) -> monthly total (mm)
et_mm = sub["Evap_tavg"] * 86400 * days          # monthly evapotranspiration (mm)
print((precip_mm - et_mm).mean(["lat", "lon"]).values)

Practical tips¶

• The preliminary (CP: GDAS, CHIRPS-Prelim) and final (C: MERRA-2, CHIRPS) versions use different forcing and give different values for the same month. The preliminary run restarts each month from the previous month's final state, so if you filled the latest months with preliminary data, replace them once the final data appear and state which version you used.
• CHIRPS covers only 50°S–50°N; poleward of that, MERRA-2 (final) or GDAS (preliminary) precipitation is used. Precipitation characteristics can change near the 50° latitude lines.
• Soil moisture is in m3 m-3 (volumetric). Convert units before comparing with GLDAS (kg m-2).
• Water fluxes are rates in kg m-2 s-1. Monthly totals are × 86400 × days in the month; summing the raw values without converting gives numbers hundreds of thousands of times too small.
• The anomaly files (MA) use the 1982–2016 climatology (MC). Anomalies on the NASA LDAS web maps or FEWS NET products may use other baselines (e.g. 1991–2020), so state your baseline when you compute your own.
• In November 2020, invalid model values over inland water were masked with the MODIS (MOD44W) land mask. Re-download data obtained before then (forcing variables _f were not affected).
• NASA LDAS reports reprocessing of the global preliminary run for May 2023, Central Asia Noah 3.6 for 2023-05-22 to 06-25, and Central Asia Noah-MP for 2021-10-01 to 2023-03-25 and 2023-05-22 to 06-21 (no posting date shown). Re-download these periods if you obtained them earlier.
• The NASA LDAS FAQ still lists East, Southern and West Africa regional domains, but according to the GES DISC README the regional products were retired in 2019 and replaced by the global product.

Notices and change history¶

References for your paper¶

Dataset citation¶

FLDAS global monthly, final (MERRA-2 and CHIRPS) — DOI 10.5067/5NHC22T9375G

@misc{fldas_noah01_c_gl_m,
  author    = {McNally, Amy},
  title     = {{FLDAS} Noah Land Surface Model {L4} Global Monthly 0.1 x 0.1 degree ({MERRA-2} and {CHIRPS})},
  year      = {2018},
  publisher = {Goddard Earth Sciences Data and Information Services Center (GES DISC)},
  address   = {Greenbelt, MD, USA},
  doi       = {10.5067/5NHC22T9375G}
}

FLDAS global monthly, preliminary (GDAS and CHIRPS-Prelim) — DOI 10.5067/L8GPRQWAWHE3

@misc{fldas_noah01_cp_gl_m,
  author    = {Jacob, Jossy and Slinski, Kimberly},
  title     = {{FLDAS} Noah Land Surface Model {L4} Global Monthly 0.1 x 0.1 degree ({GDAS} and {CHIRPS-PRELIM})},
  year      = {2021},
  publisher = {Goddard Earth Sciences Data and Information Services Center (GES DISC)},
  address   = {Greenbelt, MD, USA},
  doi       = {10.5067/L8GPRQWAWHE3}
}

FLDAS2 Noah-MP Central Asia daily — DOI 10.5067/C4IOYF41EEZB

@misc{fldas2_noahmp001_g_ca_d,
  author    = {Slinski, Kimberly and Sarmiento, Daniel},
  title     = {{FLDAS2} {Noah-MP} {GDAS} Land Surface Model {L4} Central Asia Daily 0.01 degree x 0.01 degree},
  year      = {2023},
  publisher = {Goddard Earth Sciences Data and Information Services Center (GES DISC)},
  address   = {Greenbelt, MD, USA},
  doi       = {10.5067/C4IOYF41EEZB}
}

Reference papers¶

FLDAS reference paper (sub-Saharan Africa) — DOI 10.1038/sdata.2017.12

@article{mcnally2017fldas,
  author  = {McNally, Amy and Arsenault, Kristi and Kumar, Sujay and Shukla, Shraddhanand and Peterson, Pete and Wang, Shugong and Funk, Chris and Peters-Lidard, Christa D. and Verdin, James P.},
  title   = {A land data assimilation system for sub-{Saharan} {Africa} food and water security applications},
  journal = {Scientific Data},
  volume  = {4},
  pages   = {170012},
  year    = {2017},
  doi     = {10.1038/sdata.2017.12}
}

FLDAS Central Asia dataset — DOI 10.5194/essd-14-3115-2022

@article{mcnally2022centralasia,
  author  = {McNally, Amy and Jacob, Jossy and Arsenault, Kristi and Slinski, Kimberly and Sarmiento, Daniel P. and Hoell, Andrew and Pervez, Shahriar and Rowland, James and Budde, Mike and Kumar, Sujay and Peters-Lidard, Christa and Verdin, James P.},
  title   = {A {Central} {Asia} hydrologic monitoring dataset for food and water security applications in {Afghanistan}},
  journal = {Earth System Science Data},
  volume  = {14},
  number  = {7},
  pages   = {3115--3135},
  year    = {2022},
  doi     = {10.5194/essd-14-3115-2022}
}

Acknowledgements¶

Cite the DOI of each product you use (anomalies FLDAS_NOAH01_C_GL_MA 10.5067/GNKZZBAYDF4W, climatology FLDAS_NOAH01_C_GL_MC 10.5067/9JBLK69HNL3V). NASA asks that publications include: "The data used in this study were acquired as part of the mission of NASA's Earth Science Division and archived and distributed by the Goddard Earth Sciences (GES) Data and Information Services Center (DISC)."

Information on the datasets used in this study was compiled with the help of the Korean Climate Data Navigator (KCDN) (Sim, 2026; https://doi.org/10.5281/zenodo.23300923).

Links¶

• NASA LDAS — FLDAS
• NASA LDAS — FLDAS Global (final and preliminary run schedule)
• README for FLDAS (variable tables, DOI table)
• README for FLDAS2 Noah-MP Central Asia
• GES DISC FLDAS_NOAH01_C_GL_M 001
• NASA LDAS — Reprocessed FLDAS Data