Internal Waves on the Black Sea Shelf near the Heracles Peninsula: Modeling and Observation

Abstract

The purpose consists in a combined analysis of satellite observations of surface manifestations of internal waves near the Crimean coast and the results of numerical simulation of influence of seasonal thermohaline conditions and the relief on their structure, dynamics and intensification. Methods and Results. Based on the analysis of remote sensing data using high-resolution sensors of the Landsat-8 and Sentinel-2 satellites and the theoretical estimates, the main spatial and temporal characteristics of the internal waves on the Black Sea shelf near the Heracles Peninsula were determined. According to the temperature and salinity data obtained from the satellite measurements and the research vessels measurements in 1951-2008 from the Oceanographic Data Bank of Marine Hydrophysical Institute, the structure of density stratification was investigated, and buoyancy frequency profiles in the shelf and slope area from Yevpatoria to Yalta were obtained. Vertical velocity profiles of internal waves of the first three modes on the shelf were constructed. It was revealed that phase velocity of the internal waves of the first mode in the deep-sea part varied within the range of 2.6-5 m/s, the waves of the second modewithin 1.1-2.3 m/s, and the waves of the third modewithin 0.7-1.4 m/s. The average length of the waves detected from the satellite data was 0.4 km; the longest waves, about 1.1 km, were observed most often between Yevpatoria and Sevastopol, propagating predominantly to the northeast. Within the same train, wave dispersion occurred resulting in the wavelength diminution to 0.1-0.3 km. Conclusions. The stated assumption on the cause of generation of intense internal waves conditioned by the interaction of the Rim Current jet with the shelf edge was confirmed by the results of numerical calculations. Spatial and temporal characteristics of the internal waves, the integrated data of remote sensing and the modeling results make it possible to estimate vertical exchange at the shelf and to determine the depth of the maximum Brunt-Väisälä frequency.

Characteristics of Short-Period Internal Waves in the Avacha Bay Based on the In Situ and Satellite Observations in August-September, 2018

“…Hydrological features, along with a strong bottom slope and meanders of the Kamchatka Current, interacting with the pycnocline, create more favorable conditions for the generation of IIW trains in a shallow water polygon. For the White and Black Seas, for example, it is known [12,13] that SIWs of considerable height are generated under conditions of a shallow-lying thermocline with elevated temperature gradients when it interacts with meandering fronts. Fig.…”

Numerical Analysis of Hydrodynamic and Atmospheric Impact for Formation of Internal Waves Near the Heracles Peninsula

“…Наблюдаемые проявления внутренних волн на поверхности моря подтверждаются положением мест генерации, вызванных приливным воздействием: в западной и центральной части Каламитского залива, у берегов Севастополя и Ялты. Анализ наблюдений двумерной пространственной структуры внутренних волн по спутниковым снимкам свидетельствует о распространении этих волн в районе от Евпатории до Севастополя параллельно береговой линии или кромке шельфа, ориентированном на восток [17], что согласуется с направлением построенных баротропных приливных течений. Спектральный анализ колебаний уровня моря позволил выявить максимумы в высокочастотной части спектра, которые соответствуют как основным сейшевым модам Черного моря с периодами 4,8; 3,4 ч, так и наличию колебаний с периодами 2,7 -2 ч, близким к периодам наблюдаемых волн, зарегистрированных на спутниковых снимках.…”