In Situ Stratospheric Chemistry Observations in Background and Convectively Injected Air over the United States during DCOTSS

The Dynamics and Chemistry of the Summer Stratosphere (DCOTSS) mission is a NASA Earth Venture Suborbital research project with the primary goals of investigating the impacts of convection from intense thunderstorms on the summertime stratosphere over the United States and also of characterizing the background stratosphere. Sampling on the high-altitude ER-2 aircraft for DCOTSS took place in summer 2021 and 2022 out of Palmdale, CA and Salina, KS. Numerous occurrences of elevated stratospheric water vapor were targeted and observed during the two years of observations, providing an unprecedented data set. This presentation will highlight results from the DCOTSS field deployments, with a focus on halogen photochemistry and kinetics using in situ measurements of ClO, ClONO₂, and other measured species from the mission. We will examine data both in background air and in air influenced by convection. One of the lesser-known stated objectives of DCOTSS was to sample a volcanic eruption as flights of opportunity if an explosive eruption occurred during the time period of the mission. Time permitting in this presentation, we will discuss the impact of the Hunga Tonga volcanic eruption on stratospheric chemistry in 2022.