Tropical cyclone Marlene and stratosphere-troposphere exchange

Convective tropical cyclones initiate exchanges of mass and energy between the troposphere and the stratosphere. Recent analyses of ozone and water va por measurements from Measurements of Ozone by Airbus In-Service Aircraft ( MOZAIC) data [Suhre et al., 1997] suggest that stratospheric ozone inputs t o the troposphere can occur in the tropics near zones of deep convection. I n the present paper, we analyze a case study of spectacular stratosphere-tr oposphere exchange directly linked to the strong tropical cyclone Marlene, that occurred near Mauritius and Reunion Island on April 1995. The amplitud e of the ozone peak (300 ppbv at 300 hPa) is comparable to those observed b y Suhre et al. In this case, ageostrophic phenomena dominate advective phen omena. Therefore convective effects can be at the origin of mesoscale tropo spheric ozone contaminations which affect the entire tropical free troposph ere.