April 19, 2023, 1:27 p.m.


The SAGE III/ISS Mission is proud to announce the second official release of SAGE III/ISS products (v5.3) that are suitable for use in both validation and research studies for the data products as described in the Data Product User’s Guide (DPUG). The nominal monthly release of new SAGE III/ISS events will be processed only with the v5.3 algorithm starting with February 2023. Legacy v5.2 products remain publicly available for events from June 2017 through January 2023. This statement applies to SAGE III/ISS v5.3 Solar Level 1B, Solar Level 2, and Lunar Level 2 data products. The SAGE III/ISS Team recommends upgrading to v5.3 from v5.2 because of improvements in the process of quality assurance and a novel correction scheme for mechanical disturbances resulting in reduced product uncertainties.

Vertical profiles of ozone, nitrogen dioxide (NO2), and water vapor (H2O) concentrations, as well as multi-wavelength aerosol extinction coefficient, are included in the solar Level 2 data product files. Three ozone profiles are available in this release of the solar products: an UV based mesospheric product (i.e., “Ozone_Mes” in the product files) and two Chappuis-based products. One Chappuis-based product uses a spectrally-focused fitting retrieval (i.e., “Ozone_MLR”) while the other uses a broad-spectrum retrieval scheme that is similar to that of SAGE II (i.e.,“Ozone_AO3”). Composite ozone and retrieved temperature/pressure products are not included in the v5.3 data set. Vertical profiles of ozone, nitrogen dioxide (NO2), and nitrogen trioxide (NO3) concentrations are included in the lunar Level 2 product files. Chlorine Dioxide (OClO) from lunar occultation is not included in this release. The channel wavelengths used in solar and lunar retrievals are available in the Data Product User’s Guide (DPUG).

When compared to v5.2, v5.3 improvements resulted in a net gain of 127 solar events through the end of 2022. There was a net loss of 11 lunar events between versions for this period.

Reader Software:

A reader software package is available to access the products in their native format using Python or IDL. HDF5-formatted products are compatible with open-source readers. See the reader package for examples. Product formats have changed slightly from previous versions, so new readers are required for this release. Readers for previous versions of SAGE III data are not compatible with this version. The v5.3 readers do provide backward compatibility through v5.0.

Data Access Methods:

Direct Data Download

Earthdata Search


For questions regarding data usage, please ask us on the Earthdata Forum

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