Two thirds of the planet earth are covered by oceans. Exchange processes across the ocean/atmosphere interface play a major role for the global distribution of momentum, energy, heat, water vapor, and various chemical species and thus are of significant importance for the global climate and global distribution of pollutants. The wind blowing over the ocean surface drives the air-sea exchange processes. Energy is transferred into a turbulent shear flow at the water surface and into wind waves. Both processes contribute to the near-surface turbulence in the water. The shape of the water surface directly mirrors these processes. Various remote sensing techniques such as radar scatterometry and altimetry, make use of these relations to infer parameters such as wind speed, wind direction, wave slope and significant wave height. However, all these techniques are mostly based on empirical or semi-empirical parameterization since the knowledge about the fine-scale structure of the water surface is lacking.