The Stratospheric Aerosol and Gas Experiment III installed on the International Space Station (SAGE III/ISS) mission team announces public release of newly versioned science products. This SAGE III/ISS Version 6.0 (v6) includes Solar Level 1B, Solar Level 2, and Lunar Level 2 data products.
Details of v6.0 can be found in the Release Notes and the Data Products User’s Guide. Pay special attention to these documents as the contents have changed from past versions for all three types of scientific data formats containing SAGE III/ISS data.
Major product enhancements include: filling transmission gaps, Level 1 uncertainty improvement, changes of ozone absorption cross-sections, and covariance in solar aerosol uncertainty. Derived Level 2 products developed by the SAGE Science Team that were previously available separately (aerosol/cloud flag and particle size distribution) are now included with the solar L2 package. Observations cover June 2017 through the present. Until further notice, all forward processing of SAGE III/ISS will be under v6.0, which is the suggested version, but prior legacy versions are available upon request from ASDC.
One illustration of improved data collection efficiency involves sunspots. The SAGE solar occultation data analysis has always filtered-out sunspots as part of the regular processing to release high-precision science products. Figure 1 is an example of a sunspot in the raw data, which is typically excluded when computing the Level 1 atmospheric transmission that is then used in the Level 2 processing. Early in the SAGE III/ISS mission, the exclusion of sunspot-contaminated data had little impact on the number of complete science products. However, with solar cycle 25 the increase in frequency and size of sunspots led to discarding enough scans to cause some solar occultation events to yield no science products. Figure 2 is a striking comparison of the number of sunspots measured by the NOAA Space Weather Prediction Center and the percentage of SAGE III/ISS data flagged with sunspots. To address this loss of science products, in v6 the algorithm team implemented a gap-filling technique for small gaps (< 4 points) in the fundamental data. This capability gained 103 events with accuracy similar to the non-sunspot cases. Figure 3 is the resultant v6 time-series of vertically resolved aerosol extinction coefficient at a wavelength of 1021 nm for the tropics with various terrestrial events impacting the stratosphere annotated.
Information about v6, including data availability, user documentation and quality statements, relevant links, and tools for working with the data can be found at the ASDC.
The mission will continue to provide plots of the scientific products on the browse portal for superior quality data: Quicklook and Expedited

Figure 1: Example of sunspots in SAGE III/ISS raw data for a sunset occultation event. Panels a & b are pixel (sensor) counts for multiple scans across the Sun without and with correction using the disturbance monitoring package (DMP). Panels c-e show the SAGE footprint on Sun with SDO HMI image. The abrupt dip of intensity shown in panels a & b are typically flagged and excluded when computing the Level 1 atmospheric transmission. Credit: C. Hill, https://sage.nasa.gov//wp/wp-content/uploads/2024/11/CharlesHill_SAGEIII_DMP-STM2024.pdf

Figure 2: NOAA Space Weather Prediction Center Sunspot Number and SAGE III/ISS fraction of data with sunspots. Credit: R. Manion

Figure 3: Vertically resolved SAGE III/ISS aerosol extinction coefficient at 1021 nm for the tropics. Major terrestrial events impacting the stratosphere are approximately annotated. Credit: NASA