Tides Measurement and Tidal Analysis at Jakarta Bay

Tides observation conducted for these purposes such as real-time depth of water, determination mean sea level and other tidal datums to establish a system of tidal benchmarks and data for production of tide and tidal current predictions. Center for Marine and Coastal Mapping – Geospatial Information System used water level and tides data mainly to correct the water depth measurement to chart datum. This study uses sea level observation data conducted from 20th February 2018 until 4th April 2018 at Marina Batavia, Jakarta. This study found that tidal types at this location is mixed diurnal using formzahl number. Astronomical and shallow water possible constituent were derived from the harmonic analysis. Fourier analysis gives clearly visual interpretation in frequency perspective. Several constituents inseparable because of short duration records.

TIDE AND TIDAL CURRENT IN THE BALI STRAIT, INDONESIA

Tide and tidal current model of the Bali Strait in Indonesia is produced by using a Coupled Hydrodynamical-Ecological Model for Regional and Shelf Seas (COHERENS). With its resolutions in the horizontal (500meters) and the vertical (4layers), the model well reproduces the four major tidal constituents, namely M2, S2, K1, and O1 tides, and their currents. Furthermore the model is used to investigate the tide-induced residual flow and tidal front in the Bali Strait. As a results, the tide-induced residual flow in the Bali Strait during the spring tide on May 16th in 2010 can be attributed to the variation of the strength of two eddies. The first one is the clockwise circulation in the shallow area at the wide part of the strait, while the second one is the small clockwise circulation in the south of the narrow strait. On the other hand, as suggestion from Simpson and Hunter (1974), the tidal front is determined by the value of log(H/U3) (where is the water depth in meters and the amplitude oftidal current amplitude in ms-1). The front detected by the image of sea surface temperature distribution from the satellite corresponds with the contour log(H/U3) of 6.5.