No abstract

<p><strong><em>ABSTRACT</em></strong></p> <p><em>Measurement of ocean physical param</em><em>eter</em><em>s using the CTD was conducted by </em><em>deep water expedition </em><em>INDEX-SATAL 2010 (Indonesian Expedition Sangihe-Talaud) in July-August 2010. Th</em><em>e</em><em> </em><em>aim of this </em><em>study wa</em><em>s to</em><em> determine the characteristics of water masses around the Sangihe Talaud Water where the</em><em>re </em><em>wa</em><em>s an entry passage of </em><em> Indonesian throughflow (ITF) </em><em>at</em><em> </em><em>the </em><em>west </em><em>path</em><em>way that passed through the </em><em>primary</em><em> pathway i.e., </em><em>the Sulawesi</em><em> Sea and Makassar Strait and the secondary pathway (east pathway) that passed through the Halmahera Sea. The analyses were performed by the method of the core layer and was  processed with software Ocean Data View (ODV). The results showed that in the Sangihe Talaud waters there was a meeting water masses from the North Pacific and the South Pacific. The water mass characteristics in main pathway through the Sulawesi Sea was dominated by surface and intermediate North Pacific water masses and carried by the Mindanao Currents. While the Halmahera Sea water mass was dominated by surface and intermediate South Pacific water masses carried by the New Guinea Coastal Current that moved along the Papua New Guinea and Papua coast enters to the Halmahera Sea. </em></p> <p><em> </em></p> <p><strong><em>Keywords</em></strong><em>: Index-Satal 2010, Northern Pacific Water Mass</em><em>es</em><em>, Southern Pacific Water </em></p> <em> Masses, Sangihe Talaud</em>

No abstract

West Java Province is the most vulnerable region to hydro-meteorological disasters (i.e. flood and landslide) in Indonesia. One of the main causes of these disasters is high level of rainfall. There were many global phenomena caused an increase in rainfall level in Indonesia, one of them was the Indian Ocean Dipole (IOD), especially its negative phase. By using the Dipole Mode Index (DMI), IOD strength or intensity can be determined. Besides, the composite analysis of anomalous sea surface temperature (SST), wind, and rainfall were constructed to examine the dynamics of the negative IOD and its relation to the high rainfall level in West Java. During the negative IOD (nIOD), the significant positive (negative) anomalous SST appeared around May in eastern (western-central) of Indian Ocean. The intensity of anomalous SST in the following months reached its peak in September and accompanied by strong anomalous north-westerly wind. Furthermore, the high SST and anomalous wind increased the convection activity in the southern Java Island, and consequently, the level of rainfall in West Java increased up to 8.92 mm/day and may lead the risk of hydro-meteorological disaster.

No abstract

The coastal area in Balikpapan Bay and its surrounding area has been devastated after the burst of an underwater oil pipe at the bay on March 31st, 2018, and the crude oil still continues spreading for a few days later. A three-dimensional hydrodynamic model is used to simulate the currents dynamic and investigate the influence of the current circulation on the spreading of the oil spill in Balikpapan Bay from March 31th to April 15th, 2018, to cover the event i.e. several weeks after the oil spill incident. Model results are validated by calculating the RMSE, MAPE and model skill using water level between available observation data at Semayang Port, Balikpapan station and numerical model from October 1st, 2012 to January 1st, 2013. Verification result of tidal elevation data from observation and model prediction shows a good agreement with RMSE = 7.8 cm, MAPE = 14.3% and model skill = 0.995. Surface currents circulation in Balikpapan Bay can be distinguished by the currents pattern on the spring tide and neap tide condition. During the spring tide condition, the surface currents mostly move to the east after coming out from the bay. However, the surface currents are strongly going southward after come out from the bay on the neap tide condition. Based on the satellite images captured for the next days after the event, the spreading pattern of the oil spill seems to be matched to the pattern of surface currents circulation on the spring tide condition. From the analysis of the model result, it shows that the currents circulation playing the main role to disperse the oil spill in Balikpapan Bay towards the Makassar Strait.

FAbstractPrinceion Ocean Model (POM) was used lo calculate the tidal current in Lampung Bay using diagnostic mode. The model was forced by tidal elevation, which was given along d* open boundary using a global ocean tide model-ORITIDE. The computed tidal efcvation at St. 1 and St. 2 are in a good agreement with the observed data, but the cempuled tidal current at St.I at depth 2 m is not good and moderate approximation is showed at depth 10 m. Probably, it was influenced by non-linicr effect of coastal geometry and bottom friction because of the position of current meter, mooring closed to the coasihne.Generally, the calculated tidal currents in all layers show that the water flows into the bay during flood tide and goes out from the bay during ebb tide. The tidal current becomes j strong when passing through the narrow passage of Pahawang Strait. The simulation of residual tidal current with particular emphasis on predominant constituent of M2 shows a strong inflow from the western part of the bay mouth, up to the central part of the bay, then ite strong residual current deflects to the southeast and flows out from the eastern part of the bay mouth. This flow pattern is apparent in the upper and lower layer. The other part flows to the bay head and forms an anticlockwise circulation in the "small basin' region of the bay bead. The anticlockwise circulations are showed in the upper layer and disappear Bithe layer near the bottom.

The deviation of the sea surface from the geoid reference surface is known as the Sea Surafce Topography (SST). SST is caused by several physical phenomena such as ocean wave, tides, current and atmospheric pressure loading, and the main application of SST is to determine ocean circulation. To get the SST, we use Sea Surface Height (SSH) and Mean Dynamic Topography (MDT) based on 30 years of sea-level data derived from multi-mission of satellite Altimetry and geoid height (Undulation) from Global Gravitation Model EGM-2008. Indonesia is an archipelagic country in the equatorial region that lies between Indian and Pacific oceans. Its geographical setting will affect variability of Sea Surface Topography (SST) in the Indonesian Sea. The anomaly from SST is one of the oceanic parameters that play a crucial role in the ocean dynamic and its possible hazards. We found that the characteristics differ considerably from one place to another, depending on the bathymetric depth and type of sea. The mean SSH varies from about 40 meters and rises to the east up to a height of 80 meters. Likewise, the MDT value increased from 0.5 meters to the east to a height of 1.2 meters. In closed, narrow and shallow seas, the long time-series of those surfaces are less sensitive to the effects of El Niño and La Niña as well as global sea level rise. On the other hand, global sea level rise significantly affects the characteristic of both surfaces over open and deep seas. We hope by using more spatially dense data from multi-mission satellite altimetry, we can see more detail about the local phenomena that influence SST. By studying the variability of SST from more than one cycle (18.6 years) it is expected that it can be used to understand the dynamics of the coastal area in Indonesia.