Seasonally physical characteristics of ROFI zone (Region of Freshwater Influence) in Pelabuhan Ratu Bay

Abstract

Coastal waters have many oceanographic phenomena are still being studied. One such phenomenon is how the influence of freshwater to the water mass in coastal waters. This study aims to calculate freshwater fraction, volume transport of freshwater and water mass stability. Physical water characteristics were measured by CTD (Conductivity, Temperature and Depth) deployed in 15 locations for temperature, salinity and density. The results of freshwater fraction analysis show that the west season had a greater on water fraction than the east season with value ranging from 0.40 % - 0.70 % with the amount 18.07 %, while the east season had a value of 0.02 % - 0.28 % with the amount is 7.30 %. The transport of freshwater volume in west season is 1.429.244 m3s-1 while in the east season it is 1.066 m3s-1. Water mass stability of water column in the research location has static stability with its average N2 in west and east monsoon are 0.008 cycl/s and 0.7 × 103 cycl/s, respectively. Those analyses above infer that freshwater input hugely influences physical water mass of ROFI zone in research location.