Changes to this version include: - The Level-4 soil moisture algorithm was re-calibrated to work with the substantially changed calibration of the assimilated Level-1C brightness temperatures. - The brightness temperature scaling parameters in the updated Level-4 soil moisture algorithm are based on five years of SMAP observations (April 2015 – March 2020). - The land surface modeling system underpinning the updated Level-4 soil moisture algorithm was revised in the following ways: * Improved surface aerodynamic roughness length (z0) formulation, including use of a stem area index. * Corrected an error in the fitting procedure used for one of the topography-related functions in the Catchment model, which potentially affected the simulation of soil moisture in about 2% of all land surface elements (De Lannoy et al. 2014). * Updated calibration of the microwave radiative transfer model parameters. - The updated Level-4 soil moisture algorithm includes major software upgrades, including full compliance with the Earth System Modeling Framework, a modular and extensible software design approach, for improved support of future science development. - Minor bug fixes. For the full major and minor version history, go to https://nsidc.org/data/smap/data_versions.