Wednesday, 14 January 2004: 9:00 AM
Space-borne observations link the tropical Atlantic ozone maximum and paradox to lightning
Room 612
The tropospheric column ozone has higher values over the tropical Atlantic Ocean than other areas. It should be teleconnected to sources like biomass burning and lightning over the land because no source exists over the ocean. Biomass burning and, particularly, lightning shows an obvious annual variation when they are averaged over divided regions based on their seasonal migration. On the other hand, the Tropical Tropospheric Ozone (TTO) has the more complicated annual variation because it can be affected by the variation of the two sources and also by the horizontal and vertical circulation which transports ozone towards the Atlantic Ocean. We have calculated the correlation coefficient of TTO over the tropical Atlantic Ocean with fire and lightning over land. The TTO over the southern tropical Atlantic Ocean has a maximum value during September, October and November (SON). It is highly correlated with the fire over the South Africa and the Eastern Africa and the lightning over South America. Even if the correlation coefficient of the TTO over the southern tropical Atlantic Ocean with the lightning over central Africa is low, we found that lightning over central Africa can also elevate tropospheric ozone over the southern tropical Atlantic Ocean. The TTO over the northern tropical Atlantic Ocean has a high value during June, July and August (JJA). It is positively correlated with fires over central Africa in the southern hemisphere, while negatively correlated with fires over west Africa in the northern hemisphere, which implies the tropical ozone paradox. On the other hand, TTO is highly correlated with lightning over the west Africa and the northern part of South America.
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