Tidal currents and mixing in the Lake Maracaibo estuarine system

The Lake Maracaibo estuarine system is a cooscillating coupled ocean-lake system connected through a partially mixed estuary. In this paper we examine the low frequency movements (omega < 0.1 cycles/day) in the different water bodies within this system. The harmonic and rotary spectral analyses of velocity data indicates the importance of tidal forcing within the whole system and its interaction with winds and fresh water discharge. In particular, the results indicate the existence of dominant semi-monthly oscillations in Lake Maracaibo, likely of non-linear tidal origin, and suggest that vertical stratificaction plays an important role in controlling the three-dimensional structure of tidal currents.