NASA’s ASDC released the Global Space-based Stratospheric Aerosol Climatology (GloSSAC) Version 2.23 collection. Version 2.23 extends the dataset coverage from January 1, 1979, to December 31, 2024, and includes several minor revisions. This release includes the Stratospheric Aerosol and Gas Experiment III on the International Space Station (SAGE III/ISS) version 6.0 and Optical Spectrograph and InfraRed Imager System (OSIRIS) version 7.4.
Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) data have been unavailable since January 2022. To close the gap, the current version uses a two-step approach: SAGE III/ISS data are first temporally interpolated, followed by the use of time-interpolated OSIRIS data to fill remaining gaps in regions beyond 60°S/N.
GloSSAC is a 45-year database that tracks aerosol particles in the stratosphere, collected mainly from satellites. Scientists originally created GloSSAC to help climate models understand how stratospheric aerosols affect our climate from 1979 to 2014, and have since been updated through 2021.
The dataset primarily uses measurements from the Stratospheric Aerosol and Gas Experiment (SAGE) series up until mid-2005. After that, it relies on two other instruments: Optical Spectrograph and InfraRed Imager System (OSIRIS) and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO). The team also added data from SAGE III on the International Space Station to bring the record up to the present day and to verify methods for combining different measurements.
To create a complete picture, the team fills in any missing information using data from additional satellites, as well as ground-based stations, aircraft, and weather balloons. The result is a comprehensive, worldwide dataset with no gaps, primarily tracking aerosol extinction—a measure of how these particles scatter and absorb light—at two specific wavelengths (525 and 1020 nanometers), along with other measurements when available.