Observations and simulations of ocean surface and marine atmosphere boundary layers are rapidly growing for meso-scale and diurnal to weekly and intra-seasonal variations. This session will focus on processes and interactions of both layers at these scales, particularly those involving sea surface temperature variations. Of equal interest are the generation of SST and mixed layer depth patterns and variabilities, and the interactions of such signals with the low level atmosphere. Relevant processes include, in the ocean, mild SST gradients to sharp fronts, eddies, filaments, tropical instability waves, warm pools and cold tongues, mixed layer thickness changes, and in the atmosphere, surface wind modulations, Madden-Julian waves, cyclones, and convective systems. Retroactions and coupling studies are naturally welcome, in coastal or open ocean areas, as well as work that relates the small scales to basin scale variations or links variability on the synoptic to intraseasonal timescales to interannual variability. The tropical regions are of particular interest due to the intensity of air-sea coupling, but we welcome contributions on comparable mid-latitudes processes.