On the distribution and variability of ozone in the tropical upper troposphere: Implications for tropical deep convection and chemical-dynamical coupling

Tropical ozonesonde measurements display events of substantially reduced or near-zero ozone in the upper troposphere that can be coherent over broad spatial scales. Available observations indicate that these events occur most frequently between about 300 and 100 mbar in the tropical southwest Pacific region. The spatial structure of the events suggests linkages to deep convection as the primary cause, with the potential for long-range transport from the southwest Pacific to other locations. Observations are sparse in time as well as space, but suggest possible long-term changes in tropical ozone transport and the frequency of deep convection there since the 1980s.