High-frequency internal waves in the littoral zone of a large lake

Observations in the littoral zone of a large lake (Lake Constance) revealed strong and periodic fluctuations of temperature and current velocity on timescales between 10 and 15 min associated with high-frequency internal waves. The peak in the spectral energy of the current velocity fluctuations associated with high-frequency internal waves follows the seasonal dynamics of stratification, described by the stability frequency N. A comparison between the nearshore current velocity measurements in the littoral zone with temperature measurements in the pelagic of Lake Constance revealed a strong coupling between the occurrence of high-frequency internal waves in the littoral zone and the passage of the basin-scale internal Kelvin wave with a period of about 4 d.