SMAP L4 Global Daily 9 km EASE-Grid Carbon Net Ecosystem Exchange, Version 7
Data set id:
DOI: 10.5067/3K9F0S1Q5J2U
This is the most recent version of these data.
Version Summary
Changes to this version primarily involve replacing MODIS fPAR with VIIRS fPAR as the new baseline fPAR input for the carbon model processing; and BPLUT recalibration and SOC re-initialization in response to updates to the upstream SPL4SMGP input datasets. Specifically:
- Replaced NASA EOS MODIS (MOD15A2H) fPAR with NOAA/NASA Suomi NPP VIIRS (VNP15A2H) fPAR as the new baseline 8-day fPAR inputs to the L4C model; generated a new ancillary global clear-sky fPAR climatology from the long-term (2012-2021) VIIRS record. This update enables extended L4C operations beyond the EOS MODIS era through ongoing VIIRS operations.
- Revised SPL4CMDL global BPLUT calibration and SOC initialization using soil moisture and soil temperature data from the latest SMAP L4SM Open Loop (OL7000) ensemble Catchment land model simulation. The revision results in a calibration that is more consistent with the ensemble SPL4SMGP inputs used in SPL4C production than the calibration with the single-member, unperturbed L4SM Nature Run (NR) data used in prior L4C product releases.
- The carbon model BPLUT, Vv7040, was recalibrated using the FLUXNET2015 global tower site record, which includes 356 sites representing all major global PFT classes.


The Level-4 (L4) carbon product (SPL4CMDL) provides global gridded daily estimates of net ecosystem carbon (CO2) exchange derived using a satellite data based terrestrial carbon flux model informed by the following: Soil Moisture Active Passive (SMAP) L-band microwave observations, land cover and vegetation inputs from the Moderate Resolution Imaging Spectroradiometer (MODIS), Visible Infrared Imaging Radiometer Suite (VIIRS), and the Goddard Earth Observing System Model, Version 5 (GEOS-5) land model assimilation system. Parameters are computed using an Earth-fixed, global cylindrical 9 km Equal-Area Scalable Earth Grid, Version 2.0 (EASE-Grid 2.0) projection.
Aqua, GEOS-5, L4_C, SMAP, Suomi-NPP, Terra
Data Format(s):
Temporal Coverage:
31 March 2015 to present
Temporal Resolution:
  • 1 day
Spatial Resolution:
  • 9 km
  • 9 km
Spatial Reference System(s):
WGS 84 / NSIDC EASE-Grid 2.0 Global
Spatial Coverage:
Blue outlined yellow areas on the map below indicate the spatial coverage for this data set.

Data Access & Tools

A free NASA Earthdata Login account is required to access these data. Learn More

Help Articles

General Questions & FAQs

OPeNDAP, the Open-source Project for a Network Data Access Protocol, is a NASA community standard DAP that provides a simple way for researchers to access and work with data over the internet.
SMAP Ancillary data sets are used to produce SMAP Level-1, -2, -3, and -4 standard data products.
The following table describes both the required and actual latencies for the different SMAP radiometer data sets. Latency is defined as the time (# days, hh:mm:ss) from data acquisition to product generation.
This short article describes the customization services available for SMAP data using Earthdata Search.

How to Articles

Many NSIDC DAAC data sets can be accessed using the NSIDC DAAC's Data Access Tool. This tool provides the ability to search and filter data with spatial and temporal constraints using a map-based interface.Users have the option to
To convert HDF5 files into binary format you will need to use the h5dump utility, which is part of the HDF5 distribution available from the HDF Group. How you install HDF5 depends on your operating system.
This step-by-step tutorial demonstrates how to access MODIS and SMAP data using the Application for Extracting and Exploring Analysis Ready Samples (AppEEARS). AppEEARS allows users to access, explore, and download point and area data with spatial, temporal, and parameter subsets.
The following are instructions on how to import and geolocate SMAP Level-3 Radiometer Soil Moisture HDF5 data in ENVI. Testing notes Software: ENVI Software version: 5.3 Platform: Windows 7
This How to guide outlines the steps for properly importing, projecting and visualizing HDF and NetCDF files in ArcMap. A couple of things to note before you start:
Data subscriptions are available for select NSIDC DAAC data collections. Once signed up, the subscription service automatically sends you new data as they are delivered from active NASA satellite missions.
All data from the NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC) can be accessed directly from our HTTPS file system, using wget or curl. Basic command line instructions are provided in the article below. 
NASA Earthdata Search is a map-based interface where a user can search for Earth science data, filter results based on spatial and temporal constraints, and order data with customizations including re-formatting, re-projecting, and spatial and parameter subsetting.
NASA Worldview is a map interface that allows users to interactively browse imagery, create visualizations, and download the underlying data.
NASA's Global Imagery Browse Services (GIBS) provides up to date, full resolution imagery for selected NSIDC DAAC data sets.