Role of the Land Plume in the Transport of Ozone over the Ocean during Indoex (1999)

Observations from aircraft, an island station, and two research vessels are used to investigate the development of an elevated mixed layer or land plume over the Arabian sea during the Indian Ocean Experiment Intensive Field Phase 1999 (INDOEX) through air mass modification. Much of the transport of aerosols and gases occurs in this plume located above a well-mixed convective marine boundary layer with a depth of 800–1000 m. The depth of the land plume is approximately 2000 m with the peak ozone concentrations occurring near the centre of this land plume. Significant latitudinal variations in the concentration of ozone occur in the marine boundary layer and in the plume. Mean ozone concentrations in the land plume decreased with distance from the Indian coastline.