Au cours des dernières décennies, les communautés de recherches océanographiques et atmosphérique ont démontrées que pour améliorer notre compréhension du couplage entre l'atmosphère et l'océan, et le paramétrage du flux de masse entre l'océan et l'atmosphère (gaz, aérosols, par exemple) , de moment (pour la génération de vagues et de courants marins) et d'énergie (flux de chaleur et énergie cinétique pour les courants et le processus de mélange près de la surface ) dans les modèles couplés océan-atmosphère, les vagues doivent être prises en compte. La physique du couplage dépend de la cinématique et de la dynamique du champ de vagues, y compris les processus de génération de vagues liées au vent, les interactions non-linéaires, ondes-ondes et la dissipation des vagues, cette dernière étant normalement considérée comme dominée par le déferlement. Nous présentons ici une série d'études expérimentales et numériques, démontrant l'importance du champ de vagues sur les interactions océan - atmosphère. / Over the last several decades there has been growing recognition from both the traditional oceanographic and atmospheric science communities that to better understand the coupling between the atmosphere and the ocean, and reflect that understanding in improved air-sea fluxes of mass (e.g. gases, aerosols), momentum (e.g. generation of waves and currents) and energy (e.g. heat and kinetic energy for currents and mixing) in coupled ocean-atmosphere models, surface-wave processes must be taken into account. The underlying physics of the coupling depends on the kinematics and dynamics of the wave field, including processes of wind-wave growth, nonlinear wave-wave interactions, wave-current interactions and wave dissipation, with the last normally considered dominated by wave breaking. Here we present a series of experiments, both numerical and field observations, focusing on surface wave effects on air-sea interaction processes.

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<p>The uncertainty of the climate and health effects of aerosols is still large, one important reason being lack of knowledge of the primary emissions. This thesis combines laboratory and field experiments, and process modelling in an effort to better quantify the submicrometre aerosol emissions and to understand some of the processes in the atmosphere.</p><p>A parameterisation was derived for the source flux of sea salt particles (particles m^-2s^-1) in the size range 0.02-2.8 µm dry diameter (D_p), it is the first parameterisation to almost cover two full decades of the submicrometre sea salt aerosol production, and to include the effect of water temperature. This sea salt parameterisation was validated for temperate water in the 0.1-1.1 μm D_p range using in situ size resolved emissions of marine aerosol particles, which were measured with the eddy covariance (EC) method. For periods sampled air was heated to 300ºC in order to evaporate semi-volatile organics and isolate the sea salt fraction. Comparisons with the total aerosol emissions suggest that in these emissions organic carbon and sea salt are internally mixed in the same particles. Finally an aerosol dynamics model was modified for marine conditions. In the model parameterised emissions of sea salt was included together with aerosol dynamics, chemistry and clouds representative for the marine boundary layer. The sea salt emissions are together with secondary sulphate, and cloud processing able to reproduce a typical marine aerosol size distribution and cloud condensation nuclei population.</p><p>Measurements with the EC method of the road traffic related aerosol source number flux for D_p>0.011 µm show that the major part of the aerosol fluxes is due to road traffic emissions. Both an emission factor for the whole fleet mix in Stockholm (1.4x10¹⁴ vehicle^-1 km^-1) and separate emission factors for light- and heavy-duty vehicles (HDV) were deduced. The result shows that during weekdays 70-80% of the emissions come from HDV.</p>

The uncertainty of the climate and health effects of aerosols is still large, one important reason being lack of knowledge of the primary emissions. This thesis combines laboratory and field experiments, and process modelling in an effort to better quantify the submicrometre aerosol emissions and to understand some of the processes in the atmosphere. A parameterisation was derived for the source flux of sea salt particles (particles m-2 s-1) in the size range 0.02-2.8 µm dry diameter (Dp), it is the first parameterisation to almost cover two full decades of the submicrometre sea salt aerosol production, and to include the effect of water temperature. This sea salt parameterisation was validated for temperate water in the 0.1-1.1 μm Dp range using in situ size resolved emissions of marine aerosol particles, which were measured with the eddy covariance (EC) method. For periods sampled air was heated to 300ºC in order to evaporate semi-volatile organics and isolate the sea salt fraction. Comparisons with the total aerosol emissions suggest that in these emissions organic carbon and sea salt are internally mixed in the same particles. Finally an aerosol dynamics model was modified for marine conditions. In the model parameterised emissions of sea salt was included together with aerosol dynamics, chemistry and clouds representative for the marine boundary layer. The sea salt emissions are together with secondary sulphate, and cloud processing able to reproduce a typical marine aerosol size distribution and cloud condensation nuclei population. Measurements with the EC method of the road traffic related aerosol source number flux for Dp&gt;0.011 µm show that the major part of the aerosol fluxes is due to road traffic emissions. Both an emission factor for the whole fleet mix in Stockholm (1.4x1014 vehicle-1 km-1) and separate emission factors for light- and heavy-duty vehicles (HDV) were deduced. The result shows that during weekdays 70-80% of the emissions come from HDV.

No description available.