This study quantifies the air volume injected into the stratosphere by overshooting convection detected by GOES-16/17 geostationary infrared imagery and NOAA NEXRAD precipitation echo top during the 2021 and 2022 Dynamics and Chemistry of the Summer Stratosphere (DCOTSS) missions. This analysis seeks to address a key DCOTSS science question, namely “How much tropospheric air and water is irreversibly injected into the stratosphere by convection?” A novel method for defining individual storms or a cluster of adjacent storms as objects and tracking them throughout their lifetime facilitates the analysis. Overshooting convection injected 2,178,154 - 5,360,162 km3 of air into the stratosphere in 2021 and 6,017,486 – 10,642,008 km3 in 2022 over the North American study domain with GOES being higher than GridRad during both years. GOES overshooting detections were more uncertain due to difficulty differentiating updrafts from adjacent broad areas of cold outflow. Overshooting volume from the top 10 storm objects each year contributed 37 to 52% of the total domain wide volume. Total object-lifetime volume from these top 10 events ranged from ~90,000-790,000 km3 for GOES and ~49,000-560,000 km3 for GridRad. It was found that overshooting seldomly exceeded 5% of the total anvil area, demonstrating that very small regions within convection are responsible for impacting stratosphere composition. Despite differences in overshooting characteristics by the two sensors, airmasses initiated from GOES and NEXRAD overshooting and advected forward in time had similar spatial and vertical distributions, indicating that geostationary satellite data could be used to study the long-range transport of overshooting airmasses.

The 15 January 2022 eruption of the Hunga volcano (Tonga) generated a rich spectrum of waves, some of which achieved global propagation. Among numerous platforms mon- itoring the event, two stratospheric balloons flying over the tropical Pacific provided unique observations of infrasonic wave arrivals, detecting five complete revolutions. Combined with ground measurements from the infrasound network of the International Monitor- ing System, balloon-borne observations may provide additional constraint on the scenario of the eruption, as suggested by the correlation between bursts of acoustic wave emis- sion and peaks of maximum volcanic plume top height. Balloon records also highlight previously unobserved long-range propagation of infrasound modes and their dispersion patterns. A comparison between ground- and balloon-based measurements emphasizes superior signal-to-noise ratios onboard the balloons and further demonstrates their po- tential for infrasound studies.

The eruption of the submarine Hunga volcano in January 2022 was associated with a powerful blast that injected volcanic material to altitudes up to 58 km. From a combination of various types of satellite and ground-based observations supported by transport modeling, we show evidence for an unprecedented increase in the global stratospheric water mass by 13% as compared to climatological levels, and a 5-fold increase of stratospheric aerosol load, the highest in the last three decades. Owing to the extreme injection altitude, the volcanic plume has circumnavigated the Earth in only one week and dispersed nearly pole-to-pole in three months. The unique nature and magnitude of the global stratospheric perturbation by the Hunga eruption ranks it among the most remarkable climatic events in the modern observation era, with a range of potential persistent repercussions for stratospheric composition and climate.