Water, salt and heat balance of coastal lagoons
In: Kjerfve, B. (Ed.) (1994). Coastal lagoon processes. Elsevier Oceanography Series, 60. Elsevier: Amsterdam/Oxford/New York/Tokyo. ISBN 0-444-55556-0; e-ISBN 978-0-444-88258-5. XX, 577 pp., more In: Elsevier Oceanography Series. Elsevier: Oxford; New york; Amsterdam. ISSN 0422-9894, more |
| Abstract | Water, salt and heat balance studies are surveyed and summarized within the context of coastal lagoons. The most important geomorphological factors influencing these physical processes are inlet configuration and dimensions, lagoon size and orientation with respect to prevailing winds, and water depth. Results of past water balance studies show that advective transport dominates gains and losses by rainfall, evaporation, surface runoff and groundwater seepage. All terms, however, show a distinct seasonality in response to seasonally changing winds, wet and dry periods and higher evaporative losses during summer months. Current measurements are decomposed into steady and non-steady components to show that in coastal lagoons the time varying, low frequency fluctuations are often dominant. When lagoon-shelf exchanges are restricted, tidal currents are often important only in the vicinity of inlets, and advection is primarily in response to local wind forcing. The wind driven circulation includes a downwind drift that produces a surface slope and drives a near-bottom return flow. A density driven current can be significant even in well mixed lagoons. Residual tidal flow can be important in the long term, but over shorter time intervals the net flow in response to local wind forcing is usually dominant. |
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