The Ekman spiral and Langmuir circulation

Lake Water Langmuir

The orbital motion of water induced by surface waves penetrates some metres beneath the sea surface. The direct effect of the wind, however, penetrates to a depth of scores of metres. This is because of a larger scale physical force balance than the microscale pressure anomalies causing wave motion. The resulting flow varies with depth in the Ekman spiral. Small-scale circulation cells driven by this spiral are known as Langmuir circulation cells. In the winter of 1893 4 Fridtjof Nansen's...