Lizano Omar G, Alfaro Eric J
Centro de Investigación en Ciencias del Mar y Limnología, Departamento de Física Atmosférica, Oceánica y Planetaria, Escuela de Física, Universidad de Costa Rica.
Rev Biol Trop. 2004 Dec;52 Suppl 2:77-94.
The spatial and vertical structure of the water currents and its relationship with the tidal cycles were studied using current meters in the Gulf of Nicoya. In the upper gulf, the vertical marine current differences increase as the depth increases. The water column at the station near Chira Island (upper gulf) shows the smaller changes in currents and in temperature. The flow at the station between San Lucas Island and Puntarenas (middle gulf) is the most stratified in this region. Currents with magnitudes over 100 cm/seg were measured during spring tides. Changes in the lags of the surface and bottom tidal flows were measured on the order of 100 minutes. In general, in this upper region the flows are toward the head of the gulf when the tide is flooding and toward the mouth when the tide is ebbing. In the lower gulf the circulation is more complex. Along an axis between Tárcoles and Negritos Islands, changes of velocity vectors are identified between surface and bottom. The current rotates in a different way in the water column in this region and their patterns cannot be explained only by the tidal cycles predicted for Puntarenas. These results demonstrate that the spatial and vertical variation of the marine currents of the Gulf of Nicoya is not only related to the thermohaline structure, but also to the tidal cycles and tide ranges that take place in this estuary.
利用尼科亚湾的海流计研究了水流的空间和垂直结构及其与潮汐周期的关系。在海湾上游，垂直海流差异随深度增加而增大。奇拉岛（海湾上游）附近站点的水柱显示海流和温度变化较小。圣卢卡斯岛和蓬塔雷纳斯之间站点（海湾中部）的水流在该区域分层最为明显。大潮期间测量到流速超过100厘米/秒的海流。表层和底层潮汐流的滞后变化测量值约为100分钟。总体而言，在这个上游区域，涨潮时水流向海湾头部，落潮时水流向海湾口。在海湾下游，环流更为复杂。在塔尔科莱斯岛和内格里托斯岛之间的轴线上，表层和底层之间的速度矢量发生变化。该区域水柱中的海流以不同方式旋转，其模式不能仅用蓬塔雷纳斯预测的潮汐周期来解释。这些结果表明，尼科亚湾海流的空间和垂直变化不仅与热盐结构有关，还与该河口发生的潮汐周期和潮差有关。
