Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 3 6 2003 10.5194/acpd-3-5725-2003 http://www.atmos-chem-phys-discuss.net/3/5725/2003/ http://www.atmos-chem-phys-discuss.net/3/5725/2003/acpd-3-5725-2003.html http://www.atmos-chem-phys-discuss.net/3/5725/2003/acpd-3-5725-2003.pdf 5725 5754 2003-11-13 Space-borne observations link the tropical Atlantic ozone maximum and paradox to lightning G. S. Jenkins J.-H. Ryu Department of Meteorology, Penn State University, 503 Walker Building, University Park, Pennsylvania, USA The causes of high tropospheric column ozone values over the Tropical Atlantic Ocean during September, October, and November (SON) are investigated by examining lightning during 1998–2001. The cause for high tropospheric column ozone in the hemisphere opposite of biomass burning (tropical ozone paradox) is also examined. Our results show that lightning is central to high tropospheric column ozone during SON and responsible for the tropical ozone paradox during December, January, and February (DJF) and June, July and August (JJA). During SON large numbers of flashes are observed in South America, Central and West Africa enriching the tropospheric column ozone over the Tropical Atlantic Ocean. During JJA the largest numbers of lightning flashes are observed in West Africa, enriching tropospheric column ozone to the north of 5° S in the absence biomass burning. During DJF, lightning is concentrated in South America and Central Africa enriching tropospheric column ozone south of the Equator in the absence of biomass burning.