Publications

Explore the research that has been done by our experts and team and also explore the research that has been done by using data from our data portal.


2022


A Review of Bycatch Reduction Devices for Sustainable Fishing

Fishing activities are continuously carried out in line with the needs of the world market for fishery products. This high production and market share has become an economic potential but also has the potential for exploitation of fish resources and increased fishing activity. In addition to industrial-scale fishery production activities, small-scale fishery activities have a major contribution to the exploitation of coastal resources. Unsustainable capture fisheries activities are characterized by the use of fishing gear that is not environmentally friendly. An indication of this is the high bycatch and discards. Bycatch is a serious problem faced in capture fisheries, including crab fisheries because bycatch has the potential to reduce the abundance and diversity of aquatic biota species so it dangerous the sustainability of aquatic biota diversity. Several bycatch mitigation measures and technologies have been invented and applied to reduce bycatch. However, these measures often ignore the human dimension and fishers’ involvement which play a crucial role in successful bycatch reduction. The importance of using fishing gear that can minimize bycatch should be a priority in developing sustainable capture fisheries activities. This review discusses the various types of bycatch reduction devices used for bycatch reduction efforts. One of the efforts to realize sustainable capture fisheries is to pay attention to the number of catches. Various technologies can be used to reduce the amount of bycatch by modifying the fishing gear. The use of a bycatch reduction device (BRD) is a wise choice to increase support for the sustainability of fish resource populations.

File :

Baseline data of marine debris in the Indonesia beaches

This study was conducted around the beaches in Indonesia in order to investigate the level of pollution in the marine environment. Thirteen (13) locations in six (6) regions namely: Seribu Island, Banten, South Java, Biawak Islands, West Papua, and East Nusa making up a total length of 12.84 km of the area were studied. This investigation focused on the debris around isolated beaches, tourist attraction centers, fishing zones and marine protected areas (MPA). The method employed in this study was dependent on the international coastal cleanup form. The samples of debris collected and studied varied from the year 2013 to 2018 for a thorough investigation. The beach debris monitoring equipment revealed information about the distribution, abundance, types and, effects of marine debris on the ecosystem. Moreover, the study showed that the mass of debris collected within the areas listed weighted 1113.10 kg for 34,330 collected items. Also, the average density was noted to range between 1.43 and 5.11 items/m2. However, it was observed that plastic products constituted the highest percentage of the pollutants found in almost all the stations, with plastic bags being the most dominant.

File :

2021


Modeling of tide in the Java sea coastal area between Jakarta and Cirebon, Indonesia: bathymetric data source and sensitivity tests due to bottom roughness and boundary condition

With the on-going construction of deep water port in Patimban area, a more dense marine traffic is expected to occur in the coastal belt between the ports of Jakarta and Cirebon. Precise prediction of tide is inevitably becoming more important in order to maintain safe navigation. The purpose of this work is carrying out a dedicated tidal simulation for the area in question. The presented result contains primarily the selection of bathymetric data for the development of computational domain and sensitivity tests due to bottom roughness and the quantity of elevation points along the model’s open boundaries. For the purpose of constructing a computational domain, we assess the suitability of global and national bathymetry data. Data from two water level stations in Sunda Kelapa and Cirebon ports are used to verify the model output, for example surface elevation due to tide. The simulation of tide is carried out using two-dimensional horizontal numerical model facilitated by Delft3D software. Sensitivity tests considering two bottom roughness values and three scenarios of boundary conditions are carried out. It is found that the short-term tidal simulation indicates reasonable agreement against tidal data from Sunda Kelapa and Cirebon stations. It seems that bottom roughness does not provide significant control to the resulting magnitude. We have learned that an optimum number of tidal elevation points along the boundary condition must be set. Despite of the demands in improving the tidal phase, our present results indicate promising milestones toward a precise tidal simulation for the domain in question.

File :

Oceanography Dataset in Bonpies Archipelago as Remote Island in Java Seas, Indonesia

The oceanographic data presented in this article were collected in Bonpies island, as part of the Java Seas. The data were collected by in-situ measurement from several expeditions from 2011 to 2016. The data presented here include bathymetry, sea surface temperature (SST), sea surface salinity (SSS), ocean transparency, dissolved oxygen, and pH. All data were collected by daily in-situ measurements in different seasons. There were 5768 data measured from several portable instruments, including echo-sounder and portable instruments. Calibration of the instrument was carried out before and after the survey in accordance with the protocol provided by the manufacturer. Measurements are made directly and recorded into a log sheet paper and the data format is Comma Separated Files (.csv). This in-situ data would be most useful for regional climate studies, including forecastings such as El Nino and Indian Ocean Dipole effects, oceanographic conditions, and marine resources management.

File :

Evaluation of a New Integrated Marine Instruments: RHEA (Drifter GPS Oceanography Coverage Area)

Marine instrumentation is used to make optimal use of natural resources in the marine sector in the form of storing oceanographic characteristics data. This research aims to evaluate a new Lagrangian instrument called RHEA, developed by the Marine Research Laboratory, Padjadjaran University. This research was conducted by examining the correction factors contained in the RHEA from the mechanical and electronic side to optimize the work and carry out appropriate validation of the oceanographic parameter data. The method used is by studying marine instrument literature and conducting a series of tests on the tool until it is ready for use at sea. The output of this research is in the form of literature on how the device works to be effective and efficient in collecting data about certain oceanographic factors. The result shows that RHEA has various functions: measuring pH, dissolved oxygen, temperature, turbidity, and salinity in real-time time. This instrument needs to be slightly modified again related to its design so that it can be more optimal when measuring oceanographic parameter data. In addition, in terms of data acquisition, it is necessary to improve the electronic components by replacing or adding several parts so that the data obtained can have high accuracy.

File :

Debris Drift from Estuaries: A Study Case in Muara Gembong, Jakarta Bay

Citarum River is one of the largest rivers in West Java, Indonesia. With a length of 297 km, it transfers the debris from the urban area, industry, and settlement to the ocean. This research aims to explore Marine Debris (MD) trajectories from two estuaries in Jakarta Bay. The method was included lagrangian particles with ocean currents, wind, and bathymetry conditions using GNOME software. There were three classes of simulation done in this research. MD observations were conducted in mangrove areas to validate the simulations. These simulations occurred during the northwest and southeast Monsoon period. The results showed that the debris trajectory patterns vary in the two monsoons, and waste from the two estuaries flow towards the south and southwest. In NWM, more waste moved further to the south and was stranded in the surrounding coastal areas. In SEM, waste moved towards the Jakarta bay and surrounding islands in the western and southern side of the estuaries. MD, especially the ones from Jaya estuary, affect other areas.

File :

Reconstruction Of Oil Spill Trajectory In The Java Sea, Indonesia Using Sar Imagery

Oil spill phenomena in the ocean possess a very serious threat to ocean health. On the ocean surface, oil slicks immediately start to spread and mostly end up in the ecosystem. Furthermore, it could threaten the organisms living in the ocean or impact nearby coastal area. The aim of this research was to investigate the trajectories of oil spill based on a real accident in the Java Sea. Tracking oil spills using satellite images is an efficient method that provides valuable information about trajectories, locations and the spread intensity. The objective of this study was to periodically track the trajectory of the oil spill from the Karawang incident using Sentinel-1 Synthetic Aperture Radar (SAR) images. Pre-processing of the images consisted of radiometric and geometric corrections. After the corrections, SAR images were mapped and plotted accordingly. To understand the oil spill trajectories in relation to the oceanic processes, the ocean current pattern map and surface wind roses were also analysed. The processed images from July to October 2019 show a trajectory dominated by the oil spill layers movement towards the west to northwest from the original location along with a decrease in the detected oil spill area over time. The identified trajectories of the oil spill followed the ocean current pattern and surface winds. Thus, these two parameters were considered to be the main factors responsible for the oil spill drift.

File :

A New Oceanographic Data Portal: Padjadjaran Oceanographic Data Centre (PODC)

Understanding the physio-chemical oceanic and atmospheric processes is critical in monitoring climate change. Archipelagic and Small Island countries are vulnerable to the detrimental effects of climate change, and open access oceanic databases can solve data limitations leading to further development of action plans and government policies. A website was developed (www.isea-podc.org) to distribute and augment free oceanographic data based on various in-situ sampling instruments. Oceanographers review the data collected and stored in the portal. It is led by the Marine Research Laboratory (MEAL), Padjadjaran University, in partnership with Marine Science Institute (MSI), University of the Philippines. This framework supplements information that can support marine ecosystems, fisheries, and climate science studies. Furthermore, all data are accessible to not only the academe but also decision-makers in all aspects. The data sources are student research and the new instruments (RHEA and ARHEA) developed by MEAL. In the future, the portal will be integrated with other government institutional data to provide other functional features and can yield network-wide analyses. In the next phase, collaboration from ASEAN countries should be conducted to gain more impact and provide robust datasets.

File :

2020


Oceanographic characteristics at fish aggregating device sites for tuna pole-and-line fishery in eastern Indonesia

The research was conducted to investigate the oceanographic characteristics at three traditional anchored Fish Aggregating Device (FADs) sites for tuna pole-and-line fishery in eastern Indonesia. The FADs locations, and sea surface temperature (SST) and chlorophyll-a (chl-a), salinity (sal), wave height (wav), wind (win) current (cur) were examined using a geographic information system (GIS). Relationships between Catch-per-Trip (CPT) with oceanographic characteristics (SST, chl-a, sal, wav, win and cur), were analysed using correlation and generalised additive models (GAMs) analyses. Correlation analyses was used in order to determine how strongly pairs of variables were related to one another, and generalised additive models (GAMs) were used in order to model relationships between Catch-per-Trip (response variable) and the oceanographic variables SST, chl-a, sal, wav, win and cur (predictor variables). Correlation analyses showed that significantly negative correlations were found in entire locations between SST and chl-a while in contrarily, the lowest correlation was found between CPT and chl-a. Furthermore, the GAM plots indicated that a positive association was observed between catch-per-trip and SST with approximately >26.5 °C, chl-a was <0,4 mg/m3, salinity was observed between>33 to < 34.5 (psu) for entire sites while wav was found at>0.23 for Sorong and >0,87 (m) in Larantuka and <0.64 in Pulau Bacan. Win variable had positive effects at>4.1 m/s in entire research sites while cur had a positive effect on CPT occurred at <56 (m/s) for entire locations. The GAM models showed that SST explains up to 20 % whereas chl-a explains as the lowest variable (up to 0.78 % of the deviances) in skipjack CPT relationships, and the addition of predictor variables resulted in an increase in the deviance explained. This research provides evidence that skipjack tuna CPT has relationship with oceanographic variables in eastern Indonesia.

File :

Instrumentation System for Coastal Wave Parameter Monitoring Based on Telemetry Technology Using Accelerometer

Sea waves are important in the service of marine meteorological data. Waves that occur at sea have random and complex movements, so that the height and period of the waves are difficult to measure and formulate. This study aims to design and create marine instrumentation that can measure and record the parameters of wave height and period of coastal waves in situ so that the data obtained can reflect the conditions on the field well. PVC (Polyvinyl Chloride) is used for the instrument floats. The buoyancy value of the vehicle shows a floating value of 124.97N, or the maximum amount of load that can be accommodated by the vehicle is ±12 kg. This research was conducted from November 2019 until July 2020. The pre-research conducted at the Laboratory of Marine Science and Technology, and Computer Laboratory FPIK Universitas Padjadjaran. Testing laboratory scale carried out in a static pool, Grand Pangandaran, Pangandaran Regency and field testing was conducted in the Area of Pangandaran Port, Bojong Salawe, Pangandaran Regency, West Java for 5 days with each observation time for 6 hours / day. The results obtained are x, y, and z axis data values with a total of ±3600 data. Data analysis is based on the Zero Crossing Analysis statistical using python. The results of data processing showed a wave height value of 10% (H10) with a value of 3.0 meters, and a wave period of 10% (T10) worth 6.87 seconds. Significant wave height (HS) with a value of 2.8 meters, and significant wave period of 6.8 seconds, with an average wave height of 2.7 meters, and an average wave period of 6.8 seconds. This is consistent with the wave data from BMKG which show values ranging from 2.5 to 4 meters, on June 27-30 2020 and July 1, 2020.

File :

Utilization of oceanographic Data in Supporting The National Defense and Security Analysis in Terms of Handling the Illegal Fishing in Indonesia

One of the issues in Indonesia’s maritime security is Illegal, Unreported, and Unregulated (IUU) fishing. This research focuses on how to reduce illegal fishing using oceanographic data to support agencies concerned about ocean security. The main data collected from in-situ sampling by NOAA and to support the analysis, data also collected from several reports and published articles. The results showed that many station data already stored in the global database especially in boundary seas of Indonesia. However, the data is not continuously monitored. These data (temperature, salinity, and ocean currents) also correlate with fishing locations, especially in the boundary area. Furthermore, the oceanographic data with high performance of instruments could predict the fishing locations and the changing ocean. In conclusion, ocean databases and real-time data from instruments could support the agencies to protect Indonesia’s water.

File :

2019


Performance of float artificial debris (FAD) with Lagrangian concept

The design of a tested surface drifter that is used to measure the spread of marine debris is presented. Two FADs were tested and planted a GPS/GPRS tracker unit to transmit their positions. FAD2 was modified from FAD1 with some changes in its design. Both laboratory and field tests involved buoyancy, stability and data transmit. The test results in the field showed that FAD2 was\ better than FAD1. Its design was capable to represent floating marine debris with certain sizes. The instruments were compact, nearly accurate, cost-effective, simple to manufacture and are easily adaptable in the open ocean and coastal regions. The speed and direction indicated by FAD1 and FAD2 were similar with the direction of wind and ocean current.

File :

The model of macro debris transport before reclamation and in existing condition in Jakarta Bay

Jakarta Bay as one of an area with the densest population in Indonesia became one of the highest contamination level waters in the world includes pollution of debris. Reclamation activities in Jakarta Bay will change the water conditions, and will also affect the distribution of debris at sea. Therefore, this study conducted is to determine the movement of the marine macro debris before and on the condition of the existing reclamation island in the Bay of Jakarta. The method used is simulated by the hydrodynamic model and particle trajectory models using MIKE software. Data needed for the hydrodynamic model, namely wind, tides, bathymetry, and shoreline, while for the trajectory of the particles using a data type of debris, marine macro debris weight, and debris flux. The analysis was performed for hydrodynamic model simulation results and comparison of particle trajectory models. Hydrodynamics simulations indicate if a reclamation island formation does not change significantly in the offshore area, but a simple change in the surface current pattern of the reclamation area, it also causes a decrease in the flow velocity of±0.002 to 0.02 m/s at some point. Macro debris particle trajectory simulation shows if after reclamation, macro debris tends to accumulate in the eastern Jakarta Bay in the rainy season (January), as well as in the western and eastern regions during the dry season (July).

File :

Performance of lagriangan drifter oceanography coverage area (RHEA): second phase
Drifter Oceanography Coverage Area (RHEA) is a drift tracker to capture the ocean currents combined with other properties measurements. It is equipped with GPS and a real-time data transmitter to obtain its geographical position. The purpose of this research is to provide inexpensive instruments to observe oceanographic data. The sensors installed in this instrument are obtained from local and overseas industries. This instrument could gather data about sea surface temperature (SST), depth, salinity, currents, and acidity using the lagrangian concept. RHEA’s casing tests included a vacuum test, leakage test and buoyancy test, whereas signal test covers mobile data and is satellite-based. The results showed that the stability is as expected, which is almost 1/5 of the overall height. This is to reduce the effects of wind on changes in the tool’s motion. The shaking condition was carried out by pulling the rope tied to RHEA. The slope of the tool when the pull is weak and strong ranges from 200- 600 and stabilized within 2-4 seconds. The signal test was suitable for real-time and near-real-time monitoring, and was also fit for data transfer from both seawater and freshwater environments. The sensor showed a value of 4.03-4.76. For an acidity buffer of 6.86, the values indicated a range of 6.3-6.93. Seawater temperature sensors were tested by comparing them with digital temperature devices. Temperature showed that there was no difference in the value between RHEA sensor and digital temperature, which was 25.310C versus 26 0C. This research showed that the design, data transfer and data reliability can be used in a seawater environment for the best result. 
File :

2018


Building up the database of the Level-2 Java Sea Ecoregion based on physical oceanographic parameters

The Java Sea (JS) is one of the sea with unique characteristic with especially in biodiversity and oceanographic condition. The purpose of this research is to identify the EL into level 2 in Java Sea based on oceanographic condition. The Java Sea, which covers an area of 467,000 Km2 with an average depth of 50m, is located on the Southeastern part of the Sunda Shelf. This research uses the temperature and salinity data provided by the INDESO, the sea surface height (SSH) data downloaded from the HYCOM website, and the level 2 Java Sea ecoregion shape file data from the Indonesian seas delineation team. The physical oceanographic conditions of the level 2 Java Sea ecoregions are influenced by the moonsun and their respective geographical positions. The results showed that the distribution of temperature, sea current, salinity, and Sea Surface Height differed in each Java Sea Ecoregion level 2 because it is influenced by the geographical and astronomical location of each Java Sea Ecoregion level and influenced by the monsoon that exists over Indonesia. In the east of Java Sea influence from Makassar Strait and in the west affected by Karimata Strait. Within the region, EL 6.1. (Sunda Strait), the physical oceanography condition is slightly different from other Java EL because it is strongly influenced by the Indian Ocean.

File :

Temperature-Salinity Stratification in the Eastern Indian Ocean Using Argo Float

The spatial and temporal of Temperature and Salinity in the Eastern Indian Ocean (EIO) are studied by using Argos data. EIO consisting of Pacific seawater mass which passing through Indonesian seas and mix with Indian Ocean itself that form complex formation. It reveals link among ITF, SEC, Leeuwin Current, and SJC and routes into global circulation. The purpose of this study is to describe the main physical properties variability based on Argo Floats data. The dataset is used from 80 Argo Floats during 1999-2016 within area south of Java to west of Australia with depth range 0-2000 meters. The result shows that vertical temperature and salinity profile quite homogeny near Sunda Island-West Australia. Monthly spatial distribution of temperature is founded 15-30° C, and varying in lesser Sunda. Vertical profile in 4 sections is shallow at near Java, but shows differences in 25 horizontal. Salinity profile is having range 25-34 psu. ITF is contributing to EIO mixing. Finally, salinity is a parameter that affects the EIO dynamics especially in near Australia basin. The SEC variability showed clear in between 10°S to 15°S

File :

Sonic Layer Depth Variation Analysis Utilizing BIDE (Banda ITF Dynamic Experiment) Argo Float In Situ Observation For Undersea Warfare Tactical Environment Support

Sonic Layer Depth is the vertical distance from surface to the depth where the speed of sound reach it’s local maximum. Global Navy as well as Indonesan Navy operates in this kind of layers on a daily basis, wether it be in an anti submarine warfare operation through its ships and aircrafts or in an anti-surface warfare operation waged by its submarines. For the navy, the importance of knowing the exact value of the SLD is because it determines the minimum cut off frequency and sound wave propagation above which sound tends to be trapped and below which a shadow zone exist. This has a direct impact on where the navy operates its sensors and places its platforms in the water column. The best way to estimate SLD is by performing own measurement on the ocean using instrument such as expendable bathytermographs, which can be relatively expensive and time consuming for an operational navy ships, furthermore such measurement may be impractical in the case of mission planning or emergencies. Dedicated oceanography survey for the purpose of science and defense is relatively scarce due to prioritization concerning to the budget available resulting lack of time series in situ CTD observation which cover full annual cycle variation in Indonesia waters. Banda Indonesia Through Flow Dynamic Experiment (BIDE) is multi institution and bilateral oceanography experiment led by Indonesian scientist which utilizes argo float to perform in situ CTD measurement in Banda Sea to get an adequate time series data that cover full annual cycle variation. The dataset is publicly available so defense community as well may utilize the data for defense interest such as sonic layer depth variation analysis in Banda Sea. 

File :

Microplastics Patch Based on Hydrodynamic Modeling in The North Indramayu, Java Sea

Marine debris becomes a global issue due to its impact to ecosystem, human life, and marine environment. Microplastic is one of the marine debris types that need further attention due to its long term effect in marine life. The aim of the study was to investigate the microplastic transport in Java Sea, Indramayu for seven months period. The result showed that the tidal reversing current was dominant in Java Sea, with average current speed 0.04 – 0.32 m/s. The type of tidal movement in North Indramayu, Java Sea is mixed tide prevailing semidiurnal. The transport of microplastic has a circular-reversing pattern due to influences from the currents and waves. According to the result of this study, the start point of microplastics could be estimated ranges in distance 0.9 – 5.4 km from the location where they were sampled seven months later. Microplastic that currently resides in Java Sea allegedly came from South China Sea and Pacific Ocean. The result also indicates that Java Sea has a high probability to become the largest microplastic patch in Indonesia due to its reversing current, which can trap those particles for a long time (7 months microplastics mileage range of 1258.90 km – 1399.88 km), whether they originate from other ocean region or from Indonesia itself.

File :

Wind Wave Modeling in Natuna Sea: A Comparison Among SWAN, SEAFINE, and ERA-INTERIM

This research was conducted to verify the wave height hindcasting in Natuna Sea using the SWAN (Simulating Wave Near-shore) model, which is compared with the results of hindcasting from SEAFINE (SEAMOS South Fine Grid Hindcast) and ERA-Interim. This is expected to support research on wave characteristics based on wave forecasting for 10 years in the seas among Java, Sumatera, and Kalimantan. So the purpose of this research was to test the SWAN modeling of existing models. If the results of the comparison show similar wave distribution patterns, then the settings in the SWAN model can be used for SWAN modeling in Indonesia. The SWAN model is run with the third-generation mode (GEN3), which allow wind input, quadruplet and triad interactions, whitecapping, and breaking. Comparison of hindcasting results among SWAN, SEAFINE, and ERA-Interim produces a similar wave distribution pattern, with a good correlation coefficient for 5 stations (R=0.78-0.84). The SWAN model produces the lowest Hs estimates, while the SEAFINE model produces the highest Hs of all stations. Significant wave height (Hs) 100 years return period for all stations in Natuna Sea from SWAN is 2.97-3.37 m, ERA-Interim 4.01-4.13 m, and SEAFINE 5.24-5.67 m. The setting up of wave hindcast in this research will be helpful for improving the level of sea wave hindcast in the seas among Java, Sumatera, and Kalimantan.

File :

Application of SWAN model for hindcasting wave height in Jepara coastal waters, North Java, Indonesia

SWAN (Simulating Wave Near-shore) is a numerical wave model for hindcasting/forecasting wave parameters in coastal areas. This numerical model is chosen because is suitable for shallow water. This study was conducted to verify the results of wave height hindcasting in Jepara coastal waters. This is expected to support wave characteristic research based on wave forecasting for 10 years in the waters between Java, Sumatera and Kalimantan. The model is run with the third-generation mode (GEN3), which allow wind input, quadruplet and triad interactions, whitecapping, and breaking. Wind data is obtained from ECMWF (European Centre for Medium-Range Weather Forecasts) and the bathymetry from GEBCO (General Bathymetric Chart of The Oceans). The validation of the model and buoy data during July - December 1993 shows a good result (Root Mean Square Error = 0.166 and correlation/ linear regression = 0.807). Based on the literature, qualitatively the model has been verified with other simulation from another model in the same location.

File :

2017


Pengembangan Instrumen Lagrangian Gps Drifter Combined (Gerned) Untuk Observasi Laut

Lagrangian instruments have been widely used to collect data on ocean currents and observations in Indonesian waters which require real-time data. This study emphasis the development of the GPS Drifter Combined (GERNED) in terms of design and measurement system. Test results show that GERNED can be used in lakes, shallow waters, and open seas. The construction consists of acrylic, polyethylene, and aluminum. The construction design consists of the upper part as a cover and also a place for air sensors and indicator lights, and the middle part which is the center of the micro-controller, power supply, sensors, manual data storage, and data transmission via satellite. The cost needed to make this tool is around 15,000,000 (fifteen million rupiahs) with the biggest cost being data transmission control. At the bottom is a static propeller. Tests carried out in the laboratory to see the position of the location showed the same data as field data, while field tests carried out on the island of Untung Jawa showed that the direction and movement of GERNED are the same as the movement of float tracking in general.

Links : Pengembangan Instrumen Lagrangian Gps Drifter Combined (Gerned) Untuk Observasi Laut . .

A comparison of numerical and analytical predictions of the tidal stream power resource of Massachusetts, USA

The coastal waters of Massachusetts, USA encompass tidal phenomena that generate flows of sufficient magnitude for commercially viable power extraction. We examine the tidal power resource of the Massachusetts coastal region with two high-resolution hydrodynamic tidal models: a regional model encompassing the coastal waters of southeastern New England and a local domain model of Cape Cod Canal. Both models have been subject to comprehensive skill assessment using available surface elevation and ADCP measurements. Based on the model results, we identify five high-energy sites (Cape Cod Canal, Muskeget Channel, Quicks Hole, Robinson Hole and Woods Hole) for evaluation of the maximum extractable tidal power. The power extraction at these sites is modeled using linear momentum actuator disk theory applied to a cross-channel array of turbines. Of the sites evaluated, Muskeget Channel has the greatest resource, with an estimated maximum extractable power of 24 MW. The estimated total power available from all five sites is 44 MW. These estimates agree within 21% with predictions from analytical approaches at all sites. Potential applications for the models include: providing developers with an initial assessment of the resource, guiding observation programs for further study of the resource, and facilitating optimization of turbine array design.


2016


Eddy vertical structure in southern Java Indian Ocean: Identification using automated eddies detection

The eddy characteristic in Southern Java Indian Ocean has been investigated and discussed, but spesifically deals about the vertical structure of eddy is still not much. This research was conducted to determine the eddy vertical characteristic and to find out the biggest value of kinematic energy between the cyclonic and anticyclonic eddy. The data set was from NEMO model with parameter are current and temperature from 2014. By using an automated eddy detection the veertical eddies characteristic was set developed, it includes the statistical data of each eddy location, radius, kinematic energy, temperature, and SSH at four vertical levels. The results indicated that cyclonic eddy is mostly formed in Southern Java Indian Ocean in 2014. The temperature in eddy center mostly started changing at a depth of 109 m, which is at the cyclonic eddy has a lower value and at anticyclonic has a higher value.

File :

VALIDATION OF ALTIMETER SIGNIFICANT WAVE HEIGHT USING WAVE GAUGE MEASUREMENT IN PACITAN COASTAL WATERS, EAST JAVA, INDONESIA

Research in Indonesia Indonesia rarely utilizes altimetry technology related to significant wave height (Hs). This condition is partly due to the lack of Hs comparison between satellite altimetry results and field measurements in Indonesian waters. This study was conducted to validate satellite altimetry Hs measurement results on the results of field measurements in Pacitan, East Java waters. Altimetry Hs was generated by the three satellites acquisition, in which the file was in netCDF form, then the file was converted into ASCII and the extraction of data was into a series of time using specific computer software. Statistical methods were used for the calculation of daily average significant wave heights, and the amount of Hs altimetry deviation against Hs in field for Hs data on August 2010 - February 2011. The comparison showed the field Hs = 1.959 * altimetry Hs, with the pattern of the multiplier factor regression and each Hs followed the ordo 6 polynomial function. Especially in Des-Feb (west monsoon winds), the multiplier factor was quite good (1.05), where the wind was blowing and a lot of rain in Indonesia, so that the satellite measurements got closer to the field measurements. Multiplier factor 1.959 was a considerable value, so it could be considered that altimetry Hs data was less accurate. However, it would be better if there is revalidation at different locations in one full year. 

File :

Ocean-Climate Interaction of South Eastern Indian Ocean for Tuna Fisheries & Its Socio-Economy Impacts

The complexity of the climate-ocean interactions in Indonesia is caused by the Indonesia's geographical position at the crossroads of the Indian and the Pacific Ocean. A periodic ENSO and non-periodic IOD affects Indonesian Monsoon system. A large volume of water masses from the Pacific Ocean that flows into the Indian Ocean passing through the territorial sea of Indonesia (Indonesian Through-flow) helps to provide a balance to the ocean climate in Indonesia as part their migration areas. For Tuna fisheries in Indonesia, Indian Ocean plays an important role for tuna’s habitat. This article describes the physical condition of the South Eastern Indian Ocean based on archive data of the climate-sea survey, and also describes sustainable tuna habitat based on tuna catches surveys data. The southern part of Indian Ocean is a high primary productivity area for tuna because there is a periodic Java upwelling system occurred between June and October annually, and the eddy current system encourages nutrients and chlorophyll from the coast towards the open sea. This is an excellent ocean dynamics for the sustainable tuna fisheries.

File :

Instantaneous Height of Sea Surface: A Comparison Between Local Field Observation and The Simulated Level from Global Models

This paper explores the usability of a global database containing sea surface height. We look at simulated heights of the sea surface at a certain area and compare them with field observation from three stationary stations and one from an ocean cruise. Mean Sea Surface data from the global model and Mean Sea Level (MSL) data from the field observation must be referenced to the same height system. For this reason, a height system in the form of a global ellipsoid model, namely the World Geodetic System 1984 (WGS84) was chosen as the height reference. After being referenced in the same height system, then the MSS and MSL are compared by looking for the difference between the MSS of the ellipsoid (hMSS) and the MSL of the ellipsoid (hMSL) and the average of these differences. The results show that the differences are in the order of < 1 m. The simulated tidal waves from the global model is incapable to describe the actual sea level variations, although it is able to capture the general trend. It should be noted that the field observation is incomplete and subject to various uncertainties. Bearing in mind the limitation of the models and uncertainties of the observation, our study confirms that such an order discrepancy in a global sense is tolerable

File :

2015


Suitable Locations of Ocean Renewable Energy (ORE) in Indonesia Region – GIS Approached

The purpose of this research is to find areas that are potential to produce energy from ocean with different level. The approach used was by looking at the current technological capabilities and characteristics of the currents, winds, waves, and tides. This research developed four dynamic oceanographic, combined with technologies use Geographic Information System (GIS) approach. The results elucidated that for the larger currents in eastern Indonesia with velocity up to 3 m · s–1. For the wind was in the south of Java, Papua, and West Sumatra. Tidal range that can be utilized in the area of Nusa Tenggara Timur, northern Sumatra and Papua had a height up to four meters. Waves were in the area directly facing the ocean, especially in the south of Java with a range of 1.4 m to 2.4 m. These results elucidated that Ocean Renewable Energy (ORE) in Indonesia can develop for one up to four farming in one place

File :

2013


The impact of tidal stream turbines on circulation and sediment transport in Muskeget Channel, MA.

The Finite-Volume Community Ocean Model (FVCOM) is configured to evaluate the potential impact of the proposed Muskeget Tidal Energy Project on circulation and sediment transport in the surrounding region. The extraction of tidal kinetic energy from the water column is modeled by augmenting the momentum equations with additional drag terms parameterized using local flow velocities and parameters specific to the installed turbine farm. Model-computed power output compares well with estimates based on velocities derived from a shipboard acoustic Doppler current profiler (ADCP). Total extracted power from the proposed installations during a spring ebb tide represents roughly 9% of the natural power in the deep section of the channel and 30% of the natural tidal dissipation in the turbine installation region. Due to this low level of extraction, turbine installations at the proposed transects result in relatively minor differences in the tidal current magnitude (2.5%), water level (0.8%), sediment flux (0.6%), and bed level (9%). Computations also indicate that the proposed installation generates minimal impacts to the tidal harmonics (3.3% change in amplitude and 1-min delay in phase) and tide-induced depth-averaged residual currents (2.8%). Model-computed extraction at increased levels is associated with greater perturbations to the natural conditions.

File :

2010


The Indonesian throughflow during 2004–2006 as observed by the INSTANT program

The Indonesian seas provide a sea link between the tropical Pacific and Indian Oceans. The connection is not simple, not a single gap in a ‘wall’, but rather composed of the intricate patterns of passages and seas of varied dimensions. The velocity and temperature/salinity profiles Indonesian throughflow (ITF) are altered en route from the Pacific into the Indian Ocean by sea–air buoyancy and momentum fluxes, as well as diapycnal mixing due to topographic boundary effects and dissipation of tidal energy. The INSTANT program measured the ITF in key channels from 2004 to 2006, providing the first simultaneous view of the main ITF pathways. The along-channel speeds vary markedly with passage; the Makassar and Timor flow is relatively steady in comparison to the seasonal and intraseasonal fluctuations observed in Lombok and Ombai Straits. The flow through Lifamatola Passage is strongly bottom intensified, defining the overflow into the deep Indonesian basins to the south. The 3-year mean ITF transport recorded by INSTANT into the Indian Ocean is 15 × 106 m3/s, about 30% greater than the values of non-simultaneous measurements made prior to 2000. The INSTANT 3-year mean inflow transport is nearly 13 × 106 m3/s. The 2 × 106 m3/s difference between INSTANT measured inflow and outflow is attributed to unresolved surface layer transport in Lifamatola Passage and other channels, such as Karimata Strait. Introducing inflow within the upper 200 m to zero the water column net convergence still requires upwelling within the intervening seas, notably the Banda Sea. A layer of minimum upwelling near 600 m separates upwelling within the thermocline from a deep water upwelling pattern driven by the deep overflow in Lifamatola Passage. For a steady state condition upwelling thermocline water is off-set by a 3-year mean sea to air heat flux of 80 W/m2 (after taking into account the shoaling of thermocline isotherms between the inflow and outflow portals), which agrees with the climatic value based on bulk formulae sea–air flux calculations, as well as transport weighted temperature of the inflow and outflow water. The INSTANT data reveals interannual fluctuations, with greater upwelling and sea to air heat flux in 2006.

File :

2008


Adaptive mesh refinement applied to tsunami modeling: TsunaFLASH

After the devastating Andaman-Sumatra Tsunami of December 2004, the international community has strived to introduce measures to prevent hazards from future tsunamis as much as possible. In this endeavor numerical modeling plays a key role, since forecasts as well as inundation mapping efforts rely on numerical simulation. In this presentation, we introduce a new triangle-based adaptive mesh finite element numerical model for tsunami propagation (and inundation) simulations. TsunaFLASH combines numerical methods developed in the framework of the unstructured triangular, yet non-adaptive, tsunami model TsunAWI with adaptive mesh refinement capabilities provided by the mesh refinement library amatos. Adaptive methods are well suited for accurate resolution of localized features, maintaining computational efficiency in terms of the number of computations and the required memory. This presentation will introduce the first developments of TsunaFLASH, which use bathymetry and topography data derived from ETOPO5 and focus on the Indian Ocean region. The finite element based discretization scheme with conforming and non-conforming linear elements will be introduced, as well as the coupling with the software RuptGen (Babeyko, 2007), which generates the initial uplift function. 

File :