Upper-Air Analysis for the Alamo Area Council of Governments

Sonoma Technology meteorologists investigated the relationship between temporal variability of mixing heights and regional and local ozone conditions near San Antonio during three events in fall 2021 when ozone concentrations were high. The analyses included local upper-air data collected by a radar wind profiler (RWP), sodar wind profilers (SWP), and a ceilometer, all deployed by Sonoma Technology. In addition, our meteorologists analyzed regional radiosonde measurements, radar and satellite imagery, surface weather observations, model forecasts, and smoke plume analyses to investigate conditions leading up to the days with high ozone concentrations in San Antonio. The locally sampled upper-air data clearly linked meteorological factors, such as upper-level high pressure, overnight inversions, and low-mixing heights, to high ozone levels. Smoke also enhanced ground-level ozone formation in San Antonio during the study period, when increased vertical mixing transported aloft smoke to the surface, contributing to ozone precursors. Overall, these studies demonstrated the usefulness of ceilometer and sodar wind profiler mixing height estimates in diagnosing low-level mixing heights and their potential influence on ozone formation and accumulation.