| Popis: |
The optical properties of the atmosphere over the ocean are determined by the presence of anthropogenic, rural and marine aerosols, in a ratio that is changing with the residence time ofthe air mass over the ocean. Continental aerosols are removed by a variety of processes, whereas sea spray aerosol is produced at the surface due to the interaction between wind and waves, new particles are formed and physical and chemical processes result in complex mixtures. A parameterisation of the air mass characteristics in terms of an air mass parameter (amp) has been proposed. The amp is related to the residence time ofthe air mass over the ocean and several routine measurements were proposed to quantify this parameter. In open ocean conditions this approach appears to work well, but in coastal regions significant discrepancies with experimental data have been observed. In EOPACE, an appreciable effort is made to fmd a better indicator for the amp. The April 1996 cruise with the RV 'Point Sur' offthe Californian coast was mainly dedicated to characterisation ofthe air mass, using measurements of aerosol particle size distributions and chemical composition, lidar and radiosonde profiles, and meteorological data, together with satellite images of aerosol optical depth retrieved form AVHRR data.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only. |
