The marine environment is characterized by complex interactions between the upper ocean and the atmospheric boundary layer. Oceanic fronts, particularly thermal fronts, and eddies are the most active areas for the air-sea interaction. They are the areas where two water masses, having different properties, mix. Their spatial and temporal scales range from meters to hundreds of kilometer and seconds to several days. There are several reasons for the atmosphere to be affected by oceanic fronts and eddies. Firstly as air is blown across the ocean, SST gradient, an air?sea temperature difference and air?sea humidity difference is generated. This leads to changes in near-surface stability and surface stress as well as latent and sensible heat. Secondly, the turbulent fluctuations of heat, moisture and momentum may be transported deeper into the boundary layer by large fronts and eddies resulting the formation of active weather systems. And last but not least the surface currents of ocean fronts or eddies will impact the relative motion of the air and ocean, acting to change the surface stress, thus affecting the atmosphere as well as feeding back onto the ocean.