[A-OS18] Physical Oceanography (General)

[AOS18-P06] Wave gradient and its influences within the marine atmospheric boundary layer

*Yuchun Lin¹ (1.National Taiwan Ocean University)

Keywords:Wave height gradient, wind stress curl and divergence

Surface winds within the marine atmospheric boundary layer (MABL) are often modified by the surface status underneath. The small-scale features of sea surface temperature (SST) gradient are previously shown to positively couple with the wind stress divergence and curl by perturbing the turbulences of wind in the MABL. In this study, we propose similar idea on ocean surface wave that could also modify the ocean surface wind. By analyzing the satellite measured surface wave height and wind, a negative relation between ocean surface wave height gradients and wind stresses is found over the eastern ocean basin, where the wave status mixed with wind sea and swell. The results show that the small-scale feature of wave height gradients signal a reversed energy transfer from the ocean surface to the atmosphere. These regions are mainly dominated by swell, which carries higher energy and moves faster than surface wind.