A Comparison of Stratospheric Smoke Events Seen by SAGE II (1984-2005) and SAGE III (2017-2021)

The Stratospheric Aerosol and Gas Experiment (SAGE II) operated for over 20 years (1984-2005) and collected near global observations of aerosol extinction coefficient from the upper troposphere to about40 km. SAGE III has flown aboard the International Space Station (ISS) since 2017 and has collected comparable aerosol measurements during this period. The SAGE II record is dominated by recovery from El Chichón (1982) and the Pinatubo eruption of 1991 with a few smaller volcanic events that are detectable in the data set. In addition, a number of pyrocumulus events injected smoke into the lower stratosphere with magnitudes that are comparable to the smaller volcanic events. The shorter SAGE III/ISS record is qualitatively different than SAGE II’s with a number of small to moderate volcanic eruptions in both low and high latitudes (e.g., Ambae in 2018 and Raikoke in 2020) as well several smokeevents including the two largest events seen by SAGE-like instruments: the BC pyrocumulus event in 2017 and the Australian brush fires of 2020/2021. In this paper, I will review the detection and quantification of the magnitude of these smoke events with a particular focus on the differences between the two data periods.