Abstract. The Caspian Sea is the largest enclosed basin on Earth and a
unique subject for the analysis of tidal dynamics. Tides in the basin are
produced directly by the tide-generating forces. Using the Princeton Ocean
Model (POM), we examine details of the spatial and temporal features of the
tidal dynamics in the Caspian Sea. We present tidal charts of the amplitudes
and phase lags of the major tidal constituents, together with maps of the
form factor, tidal range, and tidal current speed. Semi-diurnal tides in the
Caspian Sea are determined by a Taylor amphidromic system with
anticlockwise rotation. The largest M2 amplitude is 6 cm and is
located in Türkmen Aylagy (called Turkmen Bay hereafter). For the diurnal constituents, the Absheron Peninsula
separates two individual amphidromes with anticlockwise rotation in the
north and in the south. The maximum K1 amplitudes (up to 0.7–0.8 cm)
are located in (1) the south-eastern part of the basin, (2) Türkmenbaşy Gulf, (3) Mangyshlak Bay; and (4) Kizlyar Bay. As a
result, the semi-diurnal tides prevail over diurnal tides in the Caspian Sea.
The maximum tidal range, of up to 21 cm, has been found in Turkmen Bay. The
strongest tidal currents have been located in the straits to the north and
south of Ogurja Ada, where speeds reach 22 and 19 cm s−1, respectively.
Numerical simulations of the tides using different mean sea levels (within a
range of 5 m) indicate that spatial features of the Caspian Sea tides are
strongly sensitive to changes in mean sea level.
An early ‘Little Ice Age’ brackish water invasion along the south coast of the Caspian Sea (sediment of Langarud wetland) and its wider impacts on environment and people