Sea Surface Micro-Structure: Relation to Air-Sea Fluxes, Bubble Transport and Electromagnetic Wave Radiation

摘要

Two directions of this progrma have progressed: (1) Analysis of sea surface structure on the millimeter scale. Past analyses have focussed on the spectrum of waves. This approach does not provide full information because of the non-linear relations between short gravity waves and capillary waves. We are focusing on typical dispersed capillary trains and attempting to relate them to the sharp crested short gravity waves on which they ride. Some of the statistical features that need quantification are the rates of production and decay of the trains and the energy flux implied by the decay rates. (2) We are designing a system to estimate the heat flux from to ocean to the atmosphere in relation to the shortest waves. It is known that the existence of capillaries greatly increases various fluxes across the air-sea boundary, but it is not at all clear how this occurs. Several processes may be at work -- convergence/ divergence of orbital motions in waves disturbs the boundary layer at the top of the water where heat flux is throttled by laminar flow. This will lead to variable temperatures at the various phases of capillary waves. Another process derives from the decay of capillary trains, This delivers horizontal momentum to the water in patches corresponding to the locations of the trains. Such a patchy driving force will encourage turbulent motions of a size corresponding to the length of the train. A third process is brought about by wind stress on short gravity waves and the capillaries.