Observations of ozone production in a dissipating tropical convective cell during TC4 G. A. Morris1, A. M. Thompson2, K. E. Pickering3, S. Chen2, E. J. Bucsela4, and P. A. Kucera5 1Dept. of Physics and Astronomy, Valparaiso University, Valparaiso, IN, USA 2Dept. of Meteorology, Pennsylvania State University, University Park, PA, USA 3Atmospheric Chemistry and Dynamics Branch, Laboratory for Atmospheres, NASA Goddard Space Flight Center, Greenbelt, MD, USA 4SRI International, Menlo Park, CA, USA 5Research Applications Laboratory, NCAR, Boulder, CO, USA
Abstract. From 13 July–9 August 2007, 25 ozonesondes were launched from Las Tablas,
Panama as part of the Tropical Composition, Cloud, and Climate Coupling
(TC4) mission. On 5 August, a strong convective cell formed in the Gulf of
Panama. World Wide Lightning Location Network (WWLLN) data indicated 563
flashes (09:00–17:00 UTC) in the Gulf. NO2 data from the Ozone Monitoring
Instrument (OMI) show enhancements, suggesting lightning production of NOx.
At 15:05 UTC, an ozonesonde ascended into the southern edge of the now
dissipating convective cell as it moved west across the Azuero Peninsula.
The balloon oscillated from 2.5–5.1 km five times (15:12–17:00 UTC),
providing a unique examination of ozone (O3) photochemistry on the edge
of a convective cell. Ozone increased at a rate of ~1.6–4.6 ppbv/hr
between the first and last ascent, resulting cell wide in an increase of
~(2.1–2.5) × 106 moles of O3. This estimate
agrees to within a factor of two of our estimates of photochemical lightning
O3 production from the WWLLN flashes, from the radar-inferred lightning
flash data, and from the OMI NO2 data (~1.2, ~1.0, and ~1.7 × 106 moles, respectively), though all estimates have large
uncertainties. Examination of DC-8 in situ and lidar O3 data gathered around
the Gulf that day suggests 70–97% of the O3 change occurred in
2.5–5.1 km layer. A photochemical box model initialized with nearby TC4
aircraft trace gas data suggests these O3 production rates are possible
with our present understanding of photochemistry.
Citation: Morris, G. A., Thompson, A. M., Pickering, K. E., Chen, S., Bucsela, E. J., and Kucera, P. A.: Observations of ozone production in a dissipating tropical convective cell during TC4, Atmos. Chem. Phys., 10, 11189-11208, doi:10.5194/acp-10-11189-2010, 2010.