During a presentation at the University of Maryland, Kai Yang presented an algorithm for retrieving tropospheric O3 from EPIC by estimating the stratosphere-troposphere separation of retrieved O3 profiles. This method differs from the traditional residual method, which relies on stratospheric O3 fields from separate sources.
Validation against near-coincident O3 sonde measurements revealed that EPIC data showed a bias towards lower values by a few DU, up to 5 DU, reflecting EPIC’s reduced sensitivity to O3 in the troposphere. The spatial and temporal distributions of tropospheric O3 were found to be consistent with seasonal means of TROPOMI tropospheric O3, highlighting variations influenced by atmospheric motion, pollution, lightning, and biomass burning.
In addition to O3 measurements, Yang shared data on sulfur dioxide (SO2) levels from recent volcanic eruptions at various locations around the world, including Hawaii, Russia, Italy, Guatemala, Mexico, and the Aleutian Islands. The maximum SO2 mass loadings detected by EPIC were 430 kt from the 2022 Mauna Loa and Kilauea eruptions and 351 kt from the 2023 Sheveluch eruption, showcasing the instrument’s ability to capture and monitor volcanic emissions with remarkable accuracy.
