The spacing of Langmuir circulation under modest wind

Abstract

Spacing characteristics of Langmuir circulation (LC) are computed by large eddy simulation (LES) model under modest wind. LC is an organized vertical motion, evidenced as buoyant materials forming lines nearly parallel to the wind direction. The horizontal distribution of velocity computed by LES shows clear lines formed by LC. These lines grow and parallel to each other for a while, which we call the stable state, before they fi nally form Y-junctions. We computed spacing between every two parallel lines by averaging them under the stable state. Statistically, spacing results of 154 tests (seven wind speed cases of 22 test runs each) show high correlations between spacing and wind speed, as well as mixed layer depth. The relationship of spacing and wind is important for future LC parameterization of upper-ocean mixing.