Tidal and residual currents in a tropical estuary: Gulf of Nicoya, Costa Rica

Monitoring oceanographic parameters in bays and estuaries is crucial for sustainable development of coastal communities. The Gulf of Nicoya is the largest estuarine system in Costa Rica and plays a fundamental role in the economy of the country. In this study, we collected water level and current velocity data from ADCP recorders and estimated water density from CTD data. Using harmonic and Empirical Orthogonal Function (EOF) analyses, we examined the dominant circulation patterns in the gulf. Our results indicate that tidal forcing governs both instantaneous and residual circulation in shallower regions and density gradients have more influence in deeper and inner areas of the gulf. These findings enhance our ability to understand hydrodynamics and their potential effects on human activities in the Gulf of Nicoya.