SMAP Level-4 soil moisture and carbon data have been updated to Version 3 and are available at the NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC) via the following product pages:

SMAP L4 9 km EASE-Grid Surface and Root Zone Soil Moisture Geophysical Data (SPL4SMGP), Version 3
Data set DOI: http://dx.doi.org/10.5067/B59DT1D5UMB4

SMAP L4 9 km EASE-Grid Surface and Root Zone Soil Moisture Analysis Update (SPL4SMAU), Version 3
Data set DOI: http://dx.doi.org/10.5067/20ULJH6EZKFJ

SMAP L4 9 km EASE-Grid Surface and Root Zone Soil Moisture Land Model Constants (SPL4SMLM), Version 3
Data set DOI: http://dx.doi.org/10.5067/4IYTBSUKM57Q

SMAP L4 Global Daily 9 km Carbon Net Ecosystem Exchange (SPL4CMDL), Version 3
Data set DOI: http://dx.doi.org/10.5067/O4HAQJEWWUU8

Primary changes to SMAP Level-4 soil moisture data include:

• SMAP observations are now assimilated in Eastern Europe, the Middle East, and East Asia due to expanded coverage of the brightness temperature scaling parameters. The latter are based on two years of SMAP Version 3 brightness temperature observations where the SMOS climatology is unavailable due to RFI.
• An improved version of the model-only Nature Run (NRv4.1) simulation is used to derive the brightness temperature scaling parameters, the model soil moisture initial conditions, and the soil moisture climatology.

Primary changes to SMAP Level-4 carbon data include:

• Model now uses dynamic 8-day fPAR inputs obtained from the latest (Collection 6) MODIS fPAR record at 500 m resolution.
• Updated and recalibrated ancillary Biome Properties Look-Up Table (BPLUT) and re-initialized model initial global soil organic carbon (SOC) pools to reflect new MODIS Collection 6 fPAR inputs.

Due to a problem with the Antenna Azimuth file used to process the half-orbit 01966_A, the SMAP Science Data System (SDS) team has replaced the following files:

SMAP_L1B_TB_01966_A_20150614T231537_R14010_001.h5 (Regenerated 2017-02-11)
SMAP_L1C_TB_01966_A_20150614T231537_R14010_001.h5 (Regenerated 2017-02-14)
SMAP_L1C_TB_E_01966_A_20150614T231537_R14010_001.h5 (Regenerated 2017-02-14)
SMAP_L2_SM_P_E_01966_A_20150614T231537_R14010_001.h5 (Regenerated 2017-02-14)
SMAP_L2_SM_P_01966_A_20150614T231537_R14010_001.h5 (Regenerated 2017-02-16)

The SMAP SDS has corrected the Antenna Azimuth file and regenerated these half-orbits. Users are advised to download the replacement data files at their earliest convenience.

THE NSIDC Polaris Search and Order tool will be retired on 15 February 2017. Please contact NSIDC User Services via email: nsidc@nsidc.org with questions.

The SMAP Science Data System (SDS) has released several new and updated NASA Soil Moisture Active Passive (SMAP) radiometer data products at the NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC).

The following products have been updated to Version 4:

SMAP L2 Radiometer Half-Orbit 36 km EASE-Grid Soil Moisture (SPL2SMP)
Data Set DOI: http://dx.doi.org/10.5067/XPJTJT812XFY

SMAP L3 Radiometer Global Daily 36 km EASE-Grid Soil Moisture (SPL3SMP)
Data Set DOI: http://dx.doi.org/10.5067/OBBHQ5W22HME

The primary change implemented in this version is the addition of data from the 6:00 p.m. ascending half-orbit passes, which provides increased spatial coverage.

In addition, the following products are new to the SMAP collection:

SMAP Enhanced L1C Radiometer Half-Orbit 9 km EASE-Grid Brightness Temperatures (SPL1CTB_E)
Data Set DOI: http://dx.doi.org/10.5067/2C9O9KT6JAWS

SMAP Enhanced L2 Radiometer Half-Orbit 9 km EASE-Grid Soil Moisture (SPL2SMP_E)
Data Set DOI: http://dx.doi.org/10.5067/CE0K6JS5WQMM

SMAP Enhanced L3 Radiometer Global Daily 9 km EASE-Grid Soil Moisture (SPL3SMP_E)
Data Set DOI: http://dx.doi.org/10.5067/ZRO7EXJ8O3XI

SMAP L3 Radiometer Northern Hemisphere Daily 36 km EASE-Grid Freeze/Thaw State (SPL3FTP)
Data Set DOI: http://dx.doi.org/10.5067/RDEJQEETCNWV

SMAP Enhanced L3 Radiometer Northern Hemisphere Daily 9 km EASE-Grid Freeze/Thaw State (SPL3FTP_E)
Data Set DOI: http://dx.doi.org/10.5067/Z08PIR8RGVR2

The new enhanced radiometer products (SPL1CTB_E, SPL2SMP_E, SPL3SMP_E, and SPL3FTP_E) obtain the maximum value from the SMAP radiometer by using Backus-Gilbert optimal interpolation techniques to provide data on a finer (9 km) grid posting than the standard 36 km.

The new radiometer freeze/thaw products (SPL3FTP and SPL3FTP_E) are daily composites of Northern Hemisphere freeze/thaw conditions retrieved by the SMAP radiometer.

As of 07 December 2016, the SMAP Science Data System (SDS) has begun forward processing all products listed above. Data reprocessing from the beginning of the SMAP mission to 07 December 2016 will begin in January 2017. Registered users will be notified when reprocessing is complete.

To access data, documentation, and tools, refer to the SMAP Web site at the NSIDC DAAC: http://nsidc.org/data/smap/

The SMAP Science Data System (SDS) has completed reprocessing of the NASA SMAP Level-1B, -1C, -2, and -3 data products to Validated Version 3. Additionally, SMAP Level-4 products have been reprocessed to Validated Version 2.

During reprocessing, Level-1B, -1C, -2 and -3 data spanning the time period 19 November 2015 to 02 February 2016 were regenerated and replaced due to an issue with a spacecraft ancillary input file. The affected files end with R13080_001.h5. Users who currently have files within this date range may want to download the replacements, as portions of the right edge of the swath near 270° antenna azimuth were erroneously set to fill values.

Changes implemented in these versions are summarized on the SMAP Data Versions page: http://nsidc.org/data/smap/data_versions

To access data, documentation, and tools, visit the SMAP website at the NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC): http://nsidc.org/data/smap/

Note that SMAP Level-1 radar data and documentation are accessible through the NASA Alaska Satellite Facility Distributed Active Archive Center (ASF DAAC): https://www.asf.alaska.edu/smap/

The SMAP_L1C_TB_01966_A_20150614T231537_R13080_001.h5 file was removed from the SMAP L1C Radiometer Half-Orbit 36 km EASE-Grid Brightness Temperatures Data Set because of a problem with the Antenna Azimuth file used to process this half-orbit. The SMAP Science Data System (SDS) is working to correct the Antenna Azimuth file and regenerate these half-orbits. Once we receive the new file, we will let you know.

If you have any questions, please contact our User Services Office via e-mail: nsidc@nsidc.org. We apologize for any inconvenience this may cause you.

The SMAP Science Data System (SDS) has completed reprocessing of NASA SMAP Level-2 and -3 radar and combined radar/radiometer data to Beta Version 2. The following data sets are now available for the full radar time series, 13 April 2015 to 07 July 2015, at the NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC):

SMAP L2 Radar Half-Orbit 3 km EASE-Grid Soil Moisture (SPL2SMA)
Data Set DOI: http://dx.doi.org/10.5067/6O6GPHUJ2QXM

SMAP L2 Radar/Radiometer Half-Orbit 9 km EASE-Grid Soil Moisture (SPL2SMAP)
Data Set DOI: http://dx.doi.org/10.5067/LZIP2VM2GIA5

SMAP L3 Radar Global Daily 3 km EASE-Grid Soil Moisture (SPL3SMA)
Data Set DOI: http://dx.doi.org/10.5067/6QFA65R4RPOH

SMAP L3 Radar/Radiometer Global Daily 9 km EASE-Grid Soil Moisture (SPL3SMAP)
Data Set DOI: http://dx.doi.org/10.5067/F88YVH7CVNXS

SMAP L3 Radar Northern Hemisphere Daily 3 km EASE-Grid Freeze/Thaw State (SPL3FTA)
Data Set DOI: http://dx.doi.org/10.5067/GO4QPNEM0BKF

We are pleased to announce that all data from the NASA Soil Moisture Active Passive (SMAP) mission are now available at the National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC) and the NASA Alaska Satellite Facility Distributed Active Archive Center (ASF DAAC). The two NASA DAACs jointly manage SMAP science data on behalf of the NASA ESDIS Project.

SMAP combines coincident L-band radar and radiometer measurements to produce global, high-resolution soil moisture and freeze/thaw estimates. SMAP data available at the NSIDC DAAC include Level-1 through Level-4 radiometer data, Level-2 and Level-3 radar and combined radar/radiometer data, and Level-4 radiometer data. SMAP Level-1 radar data are available at the ASF DAAC.

Currently, Level-2 through Level-4 SMAP data are Beta-quality. Users should note that Beta-quality data use preliminary algorithms that are still being validated and are thus subject to uncertainties. Level-1 SMAP data have been processed to Validated. To access SMAP data and documentation, refer to the SMAP Data page.

We are pleased to announce that the beta version of Level-1 radiometer data from NASA’s Soil Moisture Active Passive (SMAP) mission is now available at the NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC). In addition, the beta version of Level-1 radar data is now available at the NASA Alaska Satellite Facility (ASF DAAC). SMAP combines coincident L-band radar and radiometer measurements to produce global, high-resolution soil moisture estimates.

As of 30 July 2015, the SMAP Science Data System (SDS) began forward processing Version 1 (beta) radiometer data, which will be made available at the NSIDC DAAC within 12 hours of satellite observation. Reprocessing of data from 31 March 2015 to 29 July 2015 to Version 1 has also begun and data will be made available as they are processed. This reprocessing is expected to be completed in the coming weeks, after which registered data users will receive an announcement.

The beta version (Version 1) of SMAP data sets available at the NSIDC DAAC include:

• SMAP L1A Radiometer Time-Ordered Parsed Telemetry
  Data Set DOI: http://dx.doi.org/10.5067/3G0GFQR7OT5E
• SMAP L1B Radiometer Half-Orbit Time-Ordered Brightness Temperatures
  Data Set DOI:  http://dx.doi.org/10.5067/1V33MVRRLCCT
• SMAP L1C Radiometer Half-Orbit 36 km EASE-Grid Brightness Temperatures
  Data Set DOI: http://dx.doi.org/10.5067/RP9DZ1CC6XNP

For Level-1 radar data, visit the ASF DAAC.

Data users should be aware that these data use preliminary algorithms that are still being validated and are thus subject to uncertainties. The validated release (Version 2) of all Level-1 data sets is expected to occur in the coming months, along with the beta release of the Level-2, -3, and -4 data sets.

New validation field campaign data from the Soil Moisture Active Passive Validation Experiment 2012 (SMAPVEX12) are now available at the NASA National Snow and Ice Data Center
Distributed Active Archive Center (NSIDC DAAC), including:

• Core-Based In Situ Soil Moisture Data for Agricultural Area
• Core-Based Soil Texture Data
• In Situ Vegetation Data for Forest Area

To access all currently available SMAPVEX12 data sets and documentation, visit the SMAP Validation Data Web page.

From 4:30 p.m. Wednesday, June 04 until noon Friday, June 06  (USA Mountain Time), our Web site and FTP server will be unavailable due to system maintenance. We apologize for any inconvenience this may cause you.