Air-Sea Exchange of Gases and Particles

Introductory Meteorology and Fluid Dynamics.- 1. Some Deductions from Basic Physics.- 2. Large-Scale Atmospheric Circulations.- 3. Synoptic Scale Circulations.- 4. Mesoscale Circulations.- 5. Convection and Stability.- 6. Turbulence and the Planetary Boundary Layer.- 7. Interface Dynamics.- 7.1 Flow at a solid, level surface.- 7.2 Flow at a fluid interface.- 7.3 Stability effects in the surface layer.- 7.4 Parameterization.- 8. Practical Aspects of Atmospheric Transports.- 8.1 Vertical transports.- 8.2 Horizontal transports.- Introductory Physical Oceanography.- Large-scale Oceanography.- Geostrophic, baroclinic and barotropic motions.- "Ekman" transport.- "Sverdrup" transport.- Westward intensifcation.- Physical properties of sea water.- Water property distributions and tracers.- Thermohaline circulation.- Diffusion and mixing.- Turbulent mixing.- Mesoscale Oceanography.- Ocean eddies.- Gulf stream rings.- Frontal processes.- Tides and large-scale waves.- Internal waves.- The Oceanic Mixed Layer.- Time and space scales.- Modelling the mixed layer.- Forcing variables.- Solar radiation.- Wind forcing.- Buoyancy.- Conservation relations.- Shear instabilities.- Entrainment.- Advection.- Langmuir circulations.- Role of the mixed layer in ocean dynamics and climate.- Sea Surface Waves.- Wave breaking.- Wave generation and growth.- Appendix : Definitions.- Microbiological and Organic-Chemical Processes in the Surface and Mixed Layers.- 1. Planktonic Microorganisms and Their Trophic Structure.- 1.1 Evolution of decomposing and synthesizing microorganisms and their processes.- 1.2 Trophic structure and transfer.- 1.3 Primary producers (the Phototrophs and Chemolithotrophs).- 1.4 Saprotrophs (the Heterotrophic Bacteria).- 1.5 Biotrophs (the Protozoa).- 2. Uptake and Release of Gases During the Synthesis and Decay of Organic Matter and its Control by the Solar Cycle.- 2.1 Cycling of gases and organic matter by aerobic processes.- 2.2 Cycling of gases and organic matter by anaerobic processes.- 2.3 Diel cycle of chemical activity.- 2.4 Size fractions of plankton and organic matter.- 2.5 Physical factors that control microbiological processes.- 3. Organic-Microbial Films that Form the Sea's Skin.- 3.1 Physical factors holding molecules and microbes at the sea-air interface.- 3.2 Nature of the organic films.- 3.3 Nature of the microorganisms colonizing and aggregating at the surface film.- 3.4 Spatial and temporal variation in the film.- 3.5 Crucial function of the surface film.- Gases and Their Precipitation Scavenging in the Marine Atmosphere.- 1. Introduction.- 2. Trace Gas Concentrations in Marine Air.- 2.1 Concentrations of long-lived species.- 2.2 Concentrations of short-lived species.- 2.3 Concentrations of free radicals.- 3. Homogeneous Marine Air Chemistry.- 3.1 Photochemical considerations.- 3.2 Pseudo-steady state.- 3.3 The NO-NO2-O3 subsystem.- 3.4 The CH4-CO oxidation sequence.- 3.5 The HOx and ROx radical chemistry.- 3.6 The chemistry of SO2.- 4. Exchange of Simple Soluble Gases with Hydrometeors.- 4.1 Basic principles.- 4.2 The overall mass transfer coefficient.- 4.3 Individual phase-controlled processes.- 5. Exchange of Reactive and Ionizable Gases.- 5.1 Equilibrium considerations.- 5.2 Enhancement of mass transfer rate.- 5.3 SO2 absorption by water.- 6. The Role of Circulation Within Drops.- 6.1 The work of Kronig and Brink.- 6.2 Circulation with chemical reaction.- 6.3 Comparison of theory with experimental results.- 7. Heterogeneous Processes.- 7.1 General transport equations.- 7.2 Particle-gas interaction.- 7.3 Hydrometeor-gas interaction.- 8. Scavenging in Complex Systems.- 8.1 Spatial effects and equilibrium and reversible scavenging.- 8.2 Simultaneous absorption of several gases.- Gas Transfer: Experiments and Geochemical Implications.- 1. Introduction.- 2. Laboratory Sutdies of Air-Water Gas Transfer.- 2.1 Physical transfer processes.- 2.2 Modelling approaches.- 2.3 Gases for which ra ? rw.- 2.4 Chemical transfer processes.- 3. Air-Sea Gas Transfer in the Field.- 3.1 Gases for which rw ? ra.- 3.2 The role of bubbles.- 3.3 Gases for which ra ? rw.- 4. Possible Role of Natural and Pollutant Films in Air-Sea Gas Transfer.- 4.1 Laboratory studies.- 4.2 The role of films in gas transfer at the sea surface.- 5. The Role of Air-Sea Gas Exchange in Geochemical Cycling.- 5.1 Introduction.- 5.2 Hydrogen.- 5.3 Carbon.- 5.4 Nitrogen.- 5.5 Oxygen.- 5.6 Sulphur.- 5.7 Chlorine.- 5.8 Iodine.- 5.9 Conclusions.- Air-to-Sea Transfer of Particles.- 1. Introduction.- 2. Residence Times.- 2.1 Aerosol particles.- 2.2 Wet and dry deposition velocities.- 2.3 A simple model for ?w and ?d.- 2.4 Scavenging ratios and ?w.- 2.5 Scavening rates and ?w.- 2.6 Scavenging efficiencies and ?w.- 2.7 Scavenging as a stochastic process.- 2.8 Summary.- 3. Scavenging by Precipitation.- 3.1 Rain scavenging by bugs.- 3.2 Scavenging rates and the collection efficiency.- 3.3 Collection by diffusion.- 3.4 Impaction, interception, etc..- 3.5 Collision efficiency summary.- 3.6 Approximate scavenging rates.- 4. Scavenging by Storms.- 4.1 Bomb debris data and Junge's model.- 4.2 Particle-ize dependence of scavenging ratios.- 4.3 Scavenging and precipitation efficiencies.- 4.4 Storm efficiencies.- 4.5 Summary for ?w.- 5. Dry Deposition of Particles.- 5.1 The dry flux.- 5.2 Turbulence.- 5.3 A simple two-layer model.- 5.4 Some small-scale problems.- 6. More Problems with Dry Deposition.- 6.1 The continuity equation and boundary conditions.- 6.2 Resuspension and spray scavenging.- 6.3 The constant-flux condition.- 6.4 Resistance models.- 6.5 Horizontal and vertical concentration gradients.- 6.6 Actual deposition and mass-mean values.- 6.7 Residence times, revisited.- The Production, Distribution and Bacterial Enrichment of the Sea-Salt Aerosol.- 1. Introduction.- 2. Production of the Sea-Salt Aerosol.- 2.1 Bubble-size distributions.- 2.2 Bubble dissolution.- 2.3 Percentage of sea surface producing sea-salt particles.- 2.4 Ejection of sea-salt particles from the sea.- 2.5 Seawater in the atmosphere.- 3. Distribtuion of the Sea-Salt Aerosol.- 3.1 Sea-salt concentration as a function of wind speed.- 3.2 Size distribution of sea-salt particles.- 3.3 The sea-salt inversion.- 3.4 An attempt to find the salt inversion.- 4. Enrichment of Bacteria in Jet and Film Drops.- 4.1 Jet drop enrichment.- 4.2 Film drop enrichment.- 4.3 Health hazards.- 4.4 Bacterial as ice nuclei.- 5. Conclusions.- Particle Geochemistry in the Atmosphere and Oceans.- 1. Introduction.- 2. Geochemistry of Marine Aerosols.- 2.1 Introduction.- 2.2 Rationale.- 2.3 The data bank.- 2.4 Basic criteria for source identification.- 2.5 General considerations of the composition of crustal and oceanic source aerosols.- 2.6 Two examples of source differentation for marine aerosols.- 2.7 Tracers and source markers.- 2.8 Interaction between trace pases and particles in the marine atmosphere.- 2.9 Conclusions.- 3. Geochemistry of Particle Transfer Between the Atmosphere and the Oceans.- 3.1 Introduction.- 3.2 Bubbles and the chemical composition of sea-source aerosols.- 3.3 Enrichment processes at the air-sea and bubble-seawater interfaces.- 3.4 The fate of reactive elements entering the ocean.- 4. Assessment of Particulate Fluxes from and to the Air-Sea Interface : Geochemical Implications.- 4.1 Introduction.- 4.2 Basis for the calculation of atmospheric particulate fluxes.- 4.3 General considerations of the role of air-sea particulate exchange in geochemical cycling.- 4.4 A case example: The air-sea exchange of trace metals.- 5. Conclusions.- APPENDIX A - List of Symbols.- APPENDIX B - Annotated Bibliography of Sampling.