Physical Oceanography, Vol. 13, No.
MATHEMATICAL MODELING OF MARINE SYSTEMS
ON THE MECHANISM OF CYCLONIC CIRCULATION IN LAKE KINNERET
N. B. Shapiro, V. A. Ivanov, and É. N. Mikhailova
UDC 551.465, 556.02
In summer, the circulation of water in Lake Kinneret stratified in the vertical direction is charac-
terized by the presence of a quasistationary jet coastal cyclonic current [S. Serruya, Ver. Int. Ve-
rein. Limnol., 19, 73 (1975) and S. Serruya (ed.), Lake Kinneret, Junk, Hague (1978)]. This
circulation cannot be described by a fairly complete three-dimensional baroclinic model [V. A.
Ivanov, S. P. Lyubartseva, et al., Morsk. Gidrofiz. Zh., No.
6, 26 (2001)] if the motion is in-
duced by the action of monthly average external factors. Within the framework of a two-layer
model of round lake with parabolic bottom, it was shown [H.
Ou and J.
Bennett, J. Phys.
6, 1112 (1979)] that cyclonic currents may appear under the action of daily vari-
ations of spatially homogeneous winds caused by the influence of nonlinearity and friction on the
forced Kelvin internal waves. Daily variations of the wind in the investigated region are con-
nected with the consecutive transformations of the local land breeze (i.e., a relatively weak wind
blowing from the land to the lake and characterized by the presence of wind convergence) into
the large-scale sea breeze (i.e., a practically uniform strong wind blowing from the Mediterran-
ean Sea) and vice versa. However, the numerical experiments performed by using the three-di-
mensional model of Lake Kinneret [V.
Ivanov, S. P. Lyubartseva, et al., Morsk. Gidrofiz.
6, 26 (2001)] show that, for the correct description of the circulation of waters in the
lake, it is necessary to take into account not only the time variability of the wind [see H.
R. Bennett, J. Phys. Oceanogr., No.
6, 1112 (1979)] but also its horizontal inhomogeneity,
i.e., the cyclonic vorticity of the wind, predominant in its daily variation. The indicated cyclonic
vorticity is formed during the period of land breeze as a result of the wind convergence caused
by the rotation of the Earth.
In , we present the results of numerical simulation of the seasonal variability of circulation of waters and
thermal stratification in Lake Kinneret. The numerical analysis was carried out within the framework of a multi-
layer quasiisopycnic model including the upper mixed layer (UML). As external factors, we took the action of
the atmosphere (wind stresses, heat fluxes, precipitations, and evaporation), the discharge of River Jordan, and
the use of water for economic needs. The monthly average climatic fields taken from the literature [1, 2] were
linearly interpolated in time. The atmospheric fields (of velocity and direction of winds, air temperature, cloudi-
ness, albedo, pressure of water vapor, precipitations, and the short-wave flux of solar radiation) were regarded as
horizontally homogeneous. The solution obtained in  gives a qualitatively correct description of the annual
behavior and space structure of the temperature field. Thus, in winter, the lake is practically homogeneous in the
vertical direction and the computed circulation of water is determined by the bottom topography and the
direction of winds and agrees with the generally accepted picture of currents in the lake. In summer, the lake is
strongly stratified (in the deep-water part, it, in fact, splits into two layers and has an actual topography of ther-
mocline) and the computed field of currents does not completely agree with the data of observations.
Marine Hydrophysical Institute, Ukrainian Academy of Sciences, Sevastopol. Translated from Morskoi Gidrofizicheskii Zhurnal,
30–45, January–February, 2003. Original article submitted September 3, 2001.
0928-5105/03/1301–0027 $25.00 © 2003 Plenum Publishing Corporation 27