Marine Striations in Marginal Seas and the Mediterranean Sea

The previous studies revealed that the oceanic striations are ubiquitous in the world oceans, in particular in the open oceans. But the situations are not clear in the marginal seas and the intercontinental seas. In this study we show firstly the horizontal and vertical distribution of striations in several marginal seas, such as the South China Sea, the Japan Sea, the Gulf of Mexico, and the Mediterranean Sea. Comparing to the open oceans, the striations in the marginal seas and the Mediterranean Sea have much narrower bandwidth, more zonzonal orientations in horizontal, and baroclinic structures and deep intensification in vertical. Then by power spectral analysis, the typical bandwidth of striation is about 60km in the marginal seas and 100km in the Mediterranean Sea. The orientations of oceanic striations are highly corresponding to the potential vorticity contours on isentropic surfaces. In vertica profiles, striations are always extend from the sea surface to a certain depth, but within the South China Sea and the Gulf of Mexico, they are baroclinic till to 1,000m depth and intensified at more than 3,000m depth. The differences of striations between open oceans and marginal seas are mainly dominate by the background flow, which indicate that the processes of coherent mesoscale features are more influenced by background flow in these kind of sea basins.