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A theoretical framework is presented that describes the transfer of momentum, heat and mass through the air–sea interface. It is based on the steady-state balance of turbulent kinetic energy, which allows the consistent derivation of turbulent velocity, and dissipation rate across the air–sea interface. The theory is of K – L -type with particular accuracy near the interface, which is considered to be fixed and aerodynamically smooth. Stationarity, horizontal homogeneity, and the invariance of the vertical fluxes have to be assumed. Mean profiles are discussed as results of numerical integration of the balance equations and as analytical two-or three-layer approximations. A wide range of field and laboratory data is used to determine four dimensionless tuning parameters. It is demonstrated how the stratification changes the wind and Schmidt number dependence of the gas transfer velocity. For realistic environmental conditions, profiles of velocity, temperature and carbon dioxide concentration are presented. They extend from some height in the air through the interface down to some depth in the sea. While the major transfer resistance of momentum lies within the turbulent atmospheric layer, the temperature profile is influenced by the skin layers at both sides. The flux of carbon dioxide is mainly controlled by the skin of the ocean. During calm situations the transfer is influenced by stratification changing to exclusively molecular transports for stable stratification but to free convection for unstable stratification. For passive tracers such as carbon dioxide a corresponding parameterisation of the transfer velocity is presented.

The near surface temperature profile is described by a combination of theories for the molecular skin layer (Soloviev and Schlussel, 1994) and the turbulent bulk layer (Monin and Ozmidov, 1985). The formulation presented by Soloviev et al. (1994) describes the temperature difference through the thermal molecular boundary layer, whereas similarity theories is appropriate for the turbulent bulk layers below. A combination of both theories allows for the relation of bulk temperatures at arbitrary depth of the well-mixing near-surface layer to the skin temperature of the infrared layer (10 μm thickness, from where thermal radiation is emitted into the atmosphere). In an example is shown, that for usual night-time conditions (surface heat flux of Q0 = 100 W/m2, 10-meter wind velocity varying between U10 = 0 … 25 m/s), the skin layer forms between 62 … 88 % of the oceanic temperature signal at 1 m depth. The contributions of the skin to the overall temperature signal are large for strong cooling (free convection) and strong winds (breaking of long surface waves).

A set of coupled nonlinear reaction-diffusion equations was formulated for the oxidation of CO on low-index plane Pt surfaces and solved for their spatiotemporal behaviour using continuation techniques and the method of global connections. A 2-variable model for Pt(111), consisting of the CO and O coverages as a function of time and space, gave rise to reaction fronts. In order to model the behaviour of Pt(111) or Pt(100) a third equation describing the respective adsorbate-driven phase transition had to be added. The resulting 3-variable system predicts extended regions of excitability, where pulses can be triggered. The front — respectively pulse — velocities as well as the critical radii for the nucleation were computed and compared to experimental data where available.