Surface Circulation of Lakes and Nearly Land-Locked Seas

Abstract

The pattern of surface circulation has been mapped for more than 40 lakes, marginal seas, estuaries, and lagoons. All are within the northern hemisphere, and all except one are known to have a counterclockwise pattern. This consistent pattern is attributed to the drag of wind blowing across the bodies of water. Warmer surface water is displaced to the right-hand shore zone (facing downwind), where it produces greater surface turbulence and, thus, greater wind drag. This effect leads to counterclockwise water circulation regardless of the direction and, within limits, the duration of the wind.During studies of northern hemisphere lakes and water bodies marginal to the ocean, we have noted a consistent counterclockwise circulation of surface waters. "Circulation" is here defined to mean a long-term pattern of motion, or residual motion remaining after the irregular water movements involved in wind drift, seiches, and other short-term phenomena are averaged. The averaging period is taken to be long compared with the typical passage time of weather cycles. Experimentally, such long-term patterns of flow may be directly determined, e.g., by releasing batches of drift bottles and tracing their paths of long period drift.Charts of this circulation pattern were assembled, and the cause of the pattern was examined in the expectation that it may be useful to other workers, particularly in connection with predictions of pollution down-current from points of sewage and industrial discharge into large bodies of water. Information about circulation patterns of lakes is very scarce in limnological journals, as these mainly are limited to strictly biological problems. Moreover, most studies of water movements in lakes are restricted to seiches, internal waves, and other movements in a vertical plane. Investigations of circulation in marginal seas and estuaries are more common than in lakes, possibly because of the natural landward extension of oceanographic methods. Many marginal seas are separated from the ocean by barriers caused by crustal deformation that allow little exchange of water. These are included in the discussion below. Estuaries and lagoons separated from the ocean by barriers produced by sand deposition, and marginal seas widely open to the ocean (Kars Sea, Chukchi Sea, Norwegian Sea, Bering Sea, and the North Sea) often have circulation patterns similar to those of lakes and the nearly land-locked seas, but they are omitted here because of possible control by currents from the open ocean. PatternsThe charts of horizontal circulation in lakes and nearly landlocked bodies of ocean water are so thinly and widely scattered in physical and geological literature that we probably have missed some of the published examples. Most of the ones we found are illustrated in simplified form in Figs. 1 and 2. Examples of patterns from lakes of North America listed from north to south are: Lake Superior (1), Lake Huron (1-3), Lake Michigan (1, 4), Lake Ontario (1, 5), Lake Erie (1, 6), Great Salt Lake (7), and the Salto...

Evaluation of Thermal Stratification and Flow Field Reproduced by a Three-Dimensional Hydrodynamic Model in Lake Biwa, Japan

“…It was pointed out that the third circulation flow did not exist; therefore, there were only two circulation flows [40]. These surface circulations have also been observed in other large lakes [41]. In Lake Superior, Lake Erie, Lake Constance, etc., anticlockwise circulations have been observed.…”

On the mean drift in large lakes1

“…Reversals of the mean drift with depth are predicted. Emery and Csanady (1973) have pointed out that the slow, mean surface drift in large northern hemisphere lakes is almost always in the counterclockwise direction. The observed mean speeds are in the neighborhood of 0.1 cm set-l.…”

“…Substituting in the other appropriate parameters we find: 2nmz (us) -0.1 exp (-2f/vghrL y} cos ___ D ' a net drift of 0.1 cm set-l at the lake surface which is of the required order of magnitude. Unlike the Emery and Csanady ( 1973) solution, reversals with depth are predicted, and observation may be able to distinguish the two mechanisms. Note that the mean drift is supported by a geostrophic slope of isopycnals through a thermal wind relation deriving from equation 2.…”

Horizontal structure and excitation of primary motions in a strongly stratified lake

“…Unlike basin-scale internal waves that are excited directly by wind, gyres may be excited by wind stress curl (Emery and Csanady 1973;Endoh 1986), topographic effects (Csanady 1973), residual current resulting from internal waves (Ou and Bennett 1979), and thermal effects (Huang 1971;Schwab et al 1995). Although thermal effects can be important on a seasonal timescale Akitomo et al 2004), recent studies indicate that, for timescales shorter than seasonal, wind stress curl and topographic effects are the major driving forces of gyres (Laval et al 2003(Laval et al , 2005Rueda et al 2005) and the contributions from internal waves are minor (Pan et al 2002).…”