Chemical And Physical Structure Of The Lower Atmosphere Of The Tropical Eastern North Atlantic

The chemical processes which occur in the lowermost atmosphere over the oceans have a profound effect on the global environment. There are many aspects of the marine atmosphere that we are yet to fully understand; particularly how the ocean and atmosphere interact with one another and which trace species are exchanged between them. It has been proposed that the release of halogen (Cl, Br, I) containing compounds from the surface ocean to the atmosphere can have a major impact on the destruction of low level ozone and the formation of fine particles, both entitles with climate forcing properties. Many of the species which may be released from the sea surface are highly reactive however and may exist in the atmosphere on timescales of the order of minutes. It is possible therefore that distinct concentration gradients may exist in the lower most atmosphere for certain compounds, and this may strongly impact on the environmental influence of such ocean - atmosphere fluxes. In this project we propose to measure the chemical profile of the remote marine boundary layer from 30 m above the sea surface upwards, and into the free troposphere as high as 4500 m. The chemical profiles will be determined in conjunction with other experiments making observations of ocean and atmospheric properties on a research vessel and at an atmospheric observatory. The chemical profiles obtained from an aircraft will subsequently place these point observations in a wider spatial context.