|
1G - Long-range transport of pollutants (chemicals) (WE13/5) Comparison of oceanic air-water exchange, dry deposition and wet deposition fluxes of persistent organic pollutants at the global scale. Jurado, Elena 1, Jaward, Foday2, Lohmann, Rainer2, Dachs, Jordi1, Jones, Kevin, 1 Dept. Environmental Chemistry, IIQAB-CSIc, Barcelona, Catalunya, Spain2 Environmental Science Dept., Lancaster University, Lancaster, Lancaster, United Kingdom ABSTRACT- Long-range atmospheric transport and atmospheric deposition processes are key processes driving the distribution and transport of POPs at the global scale. The relative importance of air-water exchange, dry deposition and wet deposition is a function of the pollutant physical-chemical properties affecting the gas-particle partitioning and the magnitude of biogeophysical variables such as wind speed, precipitation, etc. For example, dry deposition dominates as a depositional process for polycyclic aromatic hydrocarbons due the important role of aerosol soot carbon for these compounds. Conversely, air-water exchange is the major transfer route of polychlorinated biphenyls from the atmosphere to the ocean. The objective of this study is to assess the relative importance of air-water exchange, dry deposition and wet deposition over the ocean at the global scale. This work is based on atmospheric field measurements of PAHs, PCBs and polychlorinated dibenzo dioxins and furans during several north-south Atlantic Ocean transects. Remote sensing estimations of temperature, rain precipitation, wind speed, etc and novel parameterizations of air-water exchange and wet deposition are used to estimate the magnitude of the transfer of POPs from the atmosphere to the ocean. This approach allows to estimate the spatial distribution, seasonality and relative importance of wet deposition, air-water exchange and dry deposition over the oceans and at the global scale. Key words: atmospheric deposition, persistent organic pollutants, air water exchange, global dynamics |
