Near?Global Variability of Stratospheric Water Vapor Observed by SAGE III/ISS

The Stratospheric Aerosol and Gas Experiment III instrument on the International Space Station (SAGE III/ISS) has been making high quality solar occultation measurements of stratospheric water vapor since June 2017. Here we evaluate large-scale geophysical variability SAGE III/ISS for first 3 years observations (2017–2020) as part data validation retrieval version 5.1 (v5.1). Detailed comparisons v5.1 with Aura Microwave Limb Sounder (MLS) 5 retrievals show overall excellent agreement in terms seasonal mean structure variability. capture well-known variations including vertically propagating “tape recorder” tropics lower maxima linked to NH summer monsoons. vertical resolution (?2 km) from demonstrate contributions monsoons wet phase during Northern Hemisphere (NH) summer. Interannual over short record are also consistent between MLS stratosphere 16 30 km. We furthermore relative humidity (RH) derived measurements, highlighting detailed behavior links thermal near tropical tropopause. Spatial distributions RH at cold point tropopause (CPT) a close link minimum CPT temperature both winter summer, control