Circulation Patterns in Natural Systems Lakes and Reservoirs

Large-scale circulation patterns for a suite of lakes of different sizes and geometries are illustrated in Tables 1 (for HB) and 2 (for SML). The patterns were obtained from observations using drogues, velo-cimetry or other measurements, numerical model simulations, or both.

(1) Double-gyre wind-driven circulation In Lake Erie. Figure shows the main winter circulation from observed patterns.

- Source: Beletsky D, Saylor JH, and Schwab DJ (1999) Mean circulation in the Great Lakes. Journal of Great Lakes Research 25(1), 78-93. Reproduced with permission from the International Association for Great Lakes Research.

(2) Cyclonic Gyres in Lake Michigan. Figure shows the winter averaged currents from numerical model simulations. Colored shading represents stream function values; yellow is positive (generally anticyclonic vorticity) and the green-blue-purple areas are negative stream function (generally cyclonic vorticity).

- Source: Schwab DJ, and Beletsky D, Relative effects of wind stress curl, topography, and stratification on large-scale circulation in Lake Michigan. Journal of Geophysical research 108(C2): 3044, doi:10.1029/2001JC001066, 2003. Copyright (2003) American Geophysical Union. Reproduced with permission from the American Geophysical Union.

(3) Circulation in Lake Huron. Figure shows the main winter circulation from observed patterns.

- Source: Beletsky D, Saylor JH, and Schwab DJ (1999) Mean circulation in the Great Lakes. Journal of Great Lakes Research 25(1): 78-93. Reproduced with permission from the International Association for Great Lakes Research.

(4) Cyclonic circulation induced by wind sheltering in Lake Belau. Figure (a) shows the sheltering effect of the wind in the lake. Arrows indicate the measured wind and direction. (b) Double-gyre wind-driven circulation obtained by numerical model using an uniform spatially wind field. (c) Cyclonic circulation obtained with the model and observations using the measured, spatially variable, wind of (a).

- Source: Reprinted from Podsetchine V and Schernewski G (1999) The influence of spatial wind inhomogeneity on flow patterns in a small lake. Water Research 33(15): 3348-2256. Copyright (1999). Reproduced with permission from Elsevier.

(5) Gyres in the wind-driven circulation in Lake Trichonis. Figure shows the simulated water circulation.

- Source: Reproduced from Zacharias I and Ferentinos G (1997) A numerical model for the winter circulation in LakeTrichonis, Greece. Environmental Modelling & software 12(4): 311-321. Copyright (1997). Reproduced with permission from Elsevier.

(6) Gyres induced by diurnally varying winds in Lake Tanganyika. Figure (a) shows the simulated near-surface winds over the lake at midnight (left) and midday (right). Figure (b) shows the depth-averaged flow field, from left to right, at 00:00, 06:00, 12:00, and 18:00, for an average July day.

- Source: Podsetchine V, Huttula T, and Savijarvi H (1999) A three dimensional-circulation model of Lake Tanganyica. Hydrobiologia 407: 25-35. Copyright (1999). Reproduced with kind permission of Springer Science and Business Media.

Table 2 Circulation patterns of the SML in natural systems (lakes and reservoirs): observations and models

(1) Lake Constance

^ Rorschach

(2) Lake Kinneret

Milt

(3) Clear Lake

(4) Lake Geneva

55' 136°00'E 5

(1) Gyres induced by wind and inflow-driven currents in Upper Lake Constance. Figure shows a qualitative map of typical surface currents. The Inflow may Induce synoptic eddies; however only extreme discharges could induce the largest eddies of about 12 Km diameter.

- Source: Hollan E. Large inflow-driven vortices in Lake Constance. In Imberger J (ed.) Physical Processes in Lakes and Oceans, pp 123-136. AGU, 1998. Copyright (1998) American Geophysical Union. Reproduced with permission of the American Geophysical Union.

(2) Gyres in Lake Kinneret. Figure shows daily mean currents simulated with a numerical model (left panel) and measured (right panel).

- Source: Pan H, Avissar R, and Haidvogel DB (2002) Summer circulation and temperature structure of Lake Kinneret. Journal of Physical Oceanography, 32: 295-313. Reproduced with permission from the American Meteorological Society.

(3) Circulation induced by windfield vorticity in Clear Lake. Figure shows windfield vorticity generated by Mount Konocti (white triangle) in (a) and (b); and, model simulation of velocity field 2.5 m below free surface, with (c) spatially variable wind and (d) with a uniform wind field.

- Source: Rueda FJ, Schladow SG, Monismith SG, and Stacey MT(2005) On the effects of topography on wind and generation of currents in a large multibasin lake. Hydrobiologia 532: 139-151. Copyright (2005). Reproduced with kind permission from Springer Science and Business Media.

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