Indonesia Conference Directory

Corresponding Author
Rahaden Bagas Hatmaja

Institutions
Earth Sciences Department, Faculty of Earth Sciences and Technology, Bandung Institute of Technology

Abstract
In this research, Empirical Orthogonal Function (EOF) method is conducted to assess the dynamics of Indian Ocean characteristics, (i.e. sea surface temperature (SST) anomaly and equatorial wind), as the response of IOD for last 30 years (1988 – 2017). Based on the EOF analysis, IOD explains about 23.1% of the total variation of interannual SST anomaly (EOF second mode). While due to the equatorial wind components, IOD explains about 40.9% of the total anomalous zonal wind variation (EOF first mode) and 21.8% of the total anomalous meridional wind variation (EOF second mode). Based on the EOF and cross correlation analysis, its obtained some accurate indices and able to describe the dynamics of Indian Ocean during IOD events, such as SSTdyn (for SST anomaly dynamics), Udyn (for zonal wind anomaly dynamics), and Vdyn (for meridional anomaly dynamics). Moreover, based on the composite analysis of these Indian Ocean dynamics indices, during the five (six) positive (negative) IOD events from 1988 to 2017, the negative (positive) SST anomaly in the eastern Indian Ocean (0°–15°S dan 90°–120°E) followed by the positive (negative) SST anomaly in the western Indian Ocean (10°N–10°S dan 40°–60°E) and the central Indian Ocean (5°S–10°S dan 70°–80°E) occur in June and reach the peak in September-October. The anomalous SST is also accompanied by anomalous wind in the region of 5°N–10°S dan 70°–100°E, which starts by the occurance of anomalous northerlies (southerlies) meridional wind in June-July, continues by the occurance of anomalous easterlies (westerlies) zonal wind in the following month, and reaches the peak in October.

Keywords
Indian Ocean Dipole, Indian Ocean, sea surface temperature, equatorial surface wind, Empirical Orthogonal Function

Topic
Coastal and Ocean Dynamics

Link: https://ifory.id/abstract/KAk29p8CPVQF

Corresponding Author
Dwi Fajriyati Inaku

Institutions
a) Aquatic Resources Management, Fisheries Department, Faculty of Marine Science and Fisheries, Hasanuddin University
Jl.Perintis Kemerdekaan Km.10, Tamalanrea, Makassar 90245, Indonesia
b) Marine Science Department, Faculty of Marine Science and Fisheries, Hasanuddin University
Jl.Perintis Kemerdekaan Km.10, Tamalanrea, Makassar 90245, Indonesia

Abstract
Coastal is an area that vulnerable for change, especially along the shoreline. The changes can occur in the form of abrasion or accretion. Many factors could be the causes of shoreline changes; one of it is the existence of mangrove ecosystem. Physically, the function of mangrove ecosystem is to protect the coastal area from the wave which can cause an abrasion. It also functions as sediment trap which lead to the accretion. The aim of this research is to know the relationship between the existence of mangrove and the shoreline changes along the Takalar Regency. This research was comparing two years of Landsat Imagery (1998 and 2018) to map the mangrove and the shoreline. The shoreline changes were analyzed using Digital Shoreline Analysis System (DSAS) application, meanwhile the mangrove density was analyzed using Normalized Difference Vegetation Index (NDVI) analysis. Results show that for 20 years, shoreline changes caused by abrasion was 147,03 m or 7,38 m/year, and changes caused by accretion was 135,34 m or 6,79 m/year. Mangrove area has increased 566,37 Ha along the Takalar Regency shoreline during these 20 years. The relationship analysis between shoreline changes with mangrove density were done using simple regression. The result shows that the coefficient regression number was 0,190, which mean a weak relationship. Nonetheless, F-test shows a positive relation, which means there were influences between shoreline changes and mangrove density; if the mangrove-s density is high, then the shoreline will tend to increase (accretion). On the other hand, if the mangrove-s density is low then the shoreline will tend to decrease (abrasion).

Keywords
Shoreline changes, Mangrove, Takalar, DSAS, NDVI

Topic
Coastal and Ocean Dynamics

Link: https://ifory.id/abstract/QMBmpzwXZhUa

Corresponding Author
Farrah Hanifah

Institutions
Study Program of Oceanography, Faculty of Earth Sciences and Technology, Bandung Institute of Technology (ITB)

Abstract
This study examines the effect of Jakarta Bay reclamation on sea level height generated by storm tide using Regional Ocean Modeling System (ROMS) with tidal data sources from The Oregon State University TOPEX / Poseidon Global Inverse Solution Tidal Model Version 7.2 (TPXO 7.2), wind and atmospheric data from Interim European Center for Medium-Range Weather (ECMWF) Re-analysis (ERA-Interim) with a resolution of 1/8˚. The Simulation is carried out in two stages with the scenario before and after reclamation. Harmonic analysis using data from the model results is used to obtain astronomical tides. the effect of reclamation on water level is seen from the difference in water level from the astronomical tide before and after reclamation. the result shows that the reclamation of the Jakarta Bay is changing the tidal range in the Jakarta Bay to a greater extent. Tidal range changes can reach 0.19 m or 22.4% in Bekasi, while changes in areas that turn into reservoirs after reclamation reach 0.07 m or 7.2% (Western Garuda Reservoir) and changes at flood points can reach 0.09 m or 7.2% (Sunda Kelapa).

Keywords
sea level height, ROMS, Jakarta Bay reclamation, astronomical tide

Topic
Coastal and Ocean Dynamics

Link: https://ifory.id/abstract/jF3XzUvYMT4y

Corresponding Author
Rifky Fauzi

Institutions
Industrial and Financial Mathematics Research Group, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Bandung, 40132, Indonesia

Abstract
In this paper, the shallow water equation is modified so that it includes wind effect using Jeffreys sheltering theory. The modification allows this model to have a wave grow or decay mechanism under the action of wind gust above the surface. The wave generation or damping is investigated by calculating critical wind velocity to excite oscillatory waves on the surface. The result shows that critical wind is proportional to a numerical constant, namely the sheltering coefficient, which related to the capability of wave overcome the wind gust. Thus this model has the convenience that the critical wind speed may comparable to physical data for a suitable choice of this constant.

Keywords
shallow water equation; wave instability; wind effect; Jeffreys sheltering mechanism

Topic
Coastal and Ocean Dynamics

Link: https://ifory.id/abstract/fR7VBgqMhAkz

Corresponding Author
Fauzan Lazuardi Ramadhan

Institutions
1) Program Studi Oseanografi, Fakultas Ilmu dan Teknologi Kebumian, Institut Teknologi Bandung
2) Pusat Pengembangan Kawasan Pesisir dan Laut, Institut Teknologi Bandung
3) Kelolmpok Keahlian Oseanografi, Institut Teknologi Bandung

Abstract
The North Sulawesi Seas is the entrance gate of Indonesian Troughflow (ITF) which will be directly affected by the phenomenon occurring in the Pacific Ocean especially a El-Niño Southern Oscillation (ENSO). This study aims to determine the heat content of the water mass in the North Sulawesi Seas as part of ITF. Main data is a temperature data derived from the HYbrid Coordinate Ocean Model (HYCOM) reanalysis model with a resolution of 1/12°. In the North Sulawesi Seas found five types of a water masses its North Pacific Subtropical Water (NPSW), North Pacific Equatorial Water (NPEW), North Pacific Intermediate Water (NPIW), Antartic Intermediate Water (AAIW), and Antartic Bottom Water (AABW). The water mass heat content is calculated with the two different temperature systems for depth. Magnitudes for each heat content of water types calculated in this study for NPSW , NPEW, NPIW, AAIW, and AABW are in the range of 5,67 x 1013 – 1,04 x 1015 J / m2, 2,62 x 1015 – 8,26 x 1015 J / m2, 1,08 x 1015 – 9,38 x 1015 J / m2, 2,17 x 1016 – 3,33 x 1016 J / m2, and 8,11 x 1015 – 1,89 x 1016 J / m2, respectively.. The water mass heat content in the mixed and deep layer will decrease (increase) when the La-Niña (El-Niño), while in the thermocline layer will decrease (increase) when the El-Niño (La-Niña) phenomenon.

Keywords
North Sulawesi Seas; Indonesian Troughflow; Water mass; Heat content; and ENSO.

Topic
Coastal and Ocean Dynamics

Link: https://ifory.id/abstract/baMZ7dxhreqK

Corresponding Author
Luqman Naufal Chairuasni

Institutions
a) Department of Oceanography, Faculty of Earth Sciences and Technology, Bandung Institute of Technology – Indonesia
*luqmanaufal[at]gmail.com

b) Department of Earth Sciences, Faculty of Earth Sciences and Technology, Bandung Institute of Technology – Indonesia

c)Research Group of Oceanography, Bandung Institute of Technology - Indonesia

Abstract
The Lombok Strait that located between the island of Bali and Lombok is one of the seas in Indonesia that connects the Pacific Ocean and the Indian Ocean. Therefore, the characteristics of the Lombok Strait waters get influence from those oceans. In this research, the analysis of water masses in the Lombok Strait waters are investigated and analysed by using TS diagram. The main data used are temperature and salinity from the HYbrid Coordinate Ocean Model (HYCOM) model in 2011 – 2015 with 1/12 x 1/12 degree horizontal resolution and vertical resolution up to 1500 m. The TS diagram was used to identify water masses contribution in the Lombok Strait and the ocean heat content was calculated for each water masses. The Timor Sea Water (TSW) and Australasian Mediterranean Water (AAMW) contributed maximumly in thermocline layer with 65,85% of the total heat content (1,12 x 10^13 J/m2) and 24,46% (4,16 x 10^12 J/m2) in a row. Then, The Antartic Intermediate Water (AAIW) and Banda Intermediate Water (BIW) contributed maximumly in intermediate layer (500 – 1500 m) with 8,17% of total heat content (1,39 x 10^12 J/m2) and 1,52% (2,59 x 10^11 J/m2). In addition, each water masses influenced by El Nino Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD). The ocean heat content of TSW and BIW increased when El Nino and positive of IOD appeared and decreased during La Nina and negative of IOD. Conversely, The ocean heat content of AAMW and AAIW decreased when El Nino and positive of IOD appeared and increased during La-Nina and negative of IOD

Keywords
Water Masses; TS diagram; Ocean Heat Content; El Nino Southern Oscillation (ENSO); Indian Ocean Dipole (IOD)

Topic
Coastal and Ocean Dynamics

Link: https://ifory.id/abstract/p8R4PAJ6bBun

Corresponding Author
Putu Veri Swastika

Institutions
(1,2) Industrial and Financial Mathematics Research Group, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung, 40132, Indonesia

(3) School of Computing, Telkom University, Jl. Telekomunikasi, 1 Bandung 40257, Indonesia

Abstract
We study a simple numerical scheme based on a new type of Finite Element Method (FEM) to solve 1D Shallow Water Equation (SWE). In the new scheme, the surface elevation variable is approximated by a linear continuous base function (P1) and the velocity potential variable is approximated by one-dimensional discontinuous linear non-conforming base function (P1NC). Here, we implement the P1-P1NC finite element pair to solve the 1D SWE on a structured grid, whereas the the Runge Kutta method is adopted for time integration. We verified the resulting scheme by conducting several simulations such as a standing wave simulation, and a propagation of an initial hump over sloping bathymetry. The resulting scheme free from numerical damping error, conservative and both standing wave and shoaling phenomena are well simulated.

Keywords
finite element method, non-conformal base function, structured grid, shallow water equation.

Topic
Coastal and Ocean Dynamics

Link: https://ifory.id/abstract/tN4pnWaDKAGr

Corresponding Author
MUh Nur Fitrah Fitrah

Institutions
a) Environmental Management, Hasanuddin University, Jl. Perintis kemerdekaan 10, Makassar, 90245, South Sulawesi, Indonesia.
*pittokla[at]gmail.com
b) Departement of Marine Science, Hasanuddin University, Jl. Perintis kemerdekaan 10, Makassar, 90245, South Sulawesi, Indonesia.
c) Departement of Forestry, Hasanuddin University, Jl. Perintis Kemerdekaan 10, Makassar, 90245, South Sulawesi, Indonesia.
d) Research & Development Center for Marine, Coast, & Small Islands , Hasanuddin University, Jl.Perintis Kemerdekaan km.10, Makassar, 95245. Indonesia.
e) GeoQuest Research Centre, Faculty of Science, Medicine and Health, University of Wollongong, Australia

Abstract
As the largest tropical archipelago country, Indonesia has the widest mangrove forest in the world. In consequence, degradation of this ecosystem could affect global carbon equilibrium with increased amount of carbon in the atmosphere and reduced stored carbon. One of the potential methods to estimate this carbon stock alteration is by using remote sensing technology. The purpose of this study is to estimate amount of above ground carbon (AGC) that can be sequestered by mangrove forest on Bauluang Island and to identify its alteration dynamics during twenty years, using Landsat imageries. Landsat-7 ETM 1997, 2002, 2007, and Landsat-8 OLI 2013, and 2018 were used in this study. Amount of carbon at sample points were calculated based on classified NDVI value and the correlation were identified using linear regression to determine the range of carbon value. Carbon accuracy test was conducted to see the level of accuracy of carbon estimation using NDVI. The result shows increased amount of carbon every year with value of determination coefficient (R2) of 0.69, which means NDVI has significant influence on increased carbon stocks. The estimated amount of carbon stocks calculated based on NDVI value are 0-0.1 = 7.11 tons / ha, 0.1-0.2 = 39.71 tons / ha, 0.2-0.3 = 46.45 tons / ha, 0.3-0.4 = 276.14 tons / ha and> 0.4 = 764.32 tons / ha with an average estimation of 262.26 tons / ha. The dynamics of carbon stock shifting over the last twenty years has been increased and also declined. Amount of carbon estimated in 1997 is 11,808.23 tons, 27,357.73 tons in 2002, 36,786.58 tons in 2007, 108,538.91 tons in 2013, and 66,911.73 tons in 2018.

Keywords
Remote Sensing, Carbon Estimation, NDVI

Topic
Coastal and Ocean Dynamics

Link: https://ifory.id/abstract/DdxFhw49CkMU

Corresponding Author
Maria Artanta Ginting

Institutions
a) Industrial and Financial Mathematics Research Group, Institut Teknologi Bandung, Jalan Ganesha No. 10, Bandung 40132, Indonesia
*mariaaginting[at]s.itb.ac.id
b) School of Computing, Telkom University, Jl. Telekomunikasi No. 01 Terusan Buah Batu, Bandung 40257, Indonesia

Abstract
In conducting water wave simulations, the correct implementation of boundary conditions is important to obtain accurate wave dynamics in the computational domain. For assessment of coastal structures such as breakwaters, where both transmitted and reflected waves are present in the computational domain, we often need to observe simulation behavior for somewhat long period of time. In this case, applying a transparent boundary condition is necessary, a condition that allows transmitted wave propagates to the right, whereas reflected waves propagates to the left, at all times. In this paper, we propose a transparent boundary condition which derives from the embedded wave generation method of Liam et al. [2014]. In this paper, the method is implemented to the momentum conservative scheme of the shallow water equations, and conduct a simulation of wave reduction due to a submerged breakwater with certain dimension. Further, we measured the reflection and transmission coefficients and compare it with the analytical formulas.

Keywords
Transparent boundary condition; Embedded influxing; Momentum conservative scheme; Shallow water equations; Reflection and transmittion coefficients

Topic
Coastal and Ocean Dynamics

Link: https://ifory.id/abstract/yJUFLtfeAWVM

Corresponding Author
Iwan Pramesti Anwar

Institutions
Research Group of Oceanography, Faculty of Earth Sciences and Technology-ITB, Research Group of Oceanography, Faculty of Earth Sciences and Technology-ITB, Korea-Indonesia Marine Technology Cooperation Research Center; MTCRC, Pusat Penelitian Oseanografi-LIPI

Abstract
The north of West Papua and the Halmahera Sea is the inflow area of the eastern part of Indonesian Throughflow (ITF). The Nusa Manggala leg-3 expedition in 2018 was held on December 6-16 2018. The survey achieved twenty-six Conductivity Temperature Depth measurement points. The results of this study prove that Pacific Surface Water is present on the surface up to 70 m with a temperature of 26-30oC. South Pacific Subtropical Water and South Pacific Intermediate Water are simultaneously 70 m - 250 m and 250 m - 1000 m. The temperature at the spatial distance between 29.25 in the round around Sorong to 30.75oC in the southern part of the Gulf of Veda. Meanwhile, the highest salinity value was 34.25 psu in the vicinity of the Weda Bay and the lowest was 33.55 psu around Sorong.

Keywords
Water mass, eastern part of ITF, Nusa Manggala Survey

Topic
Coastal and Ocean Dynamics

Link: https://ifory.id/abstract/D8bRMnxhXKaN

Corresponding Author
Nida El-Islamy Qomaruddin

Institutions
Oceanography Department, Faculty of Earth Sciences and Technology, Institut Teknologi Bandung, Bandung

Abstract
The Timor and Arafura Seas are part of the Eastern Archipelago waters which directly meet the Indian Ocean and make the Timor Sea as the largest exit of Indonesian Throughflow. The aims of this research are to study the structure of stratification, types and contribution of water masses in the Timor and Arafura Seas. This study used temperature, salinity, and density data from Conductivity, Temperature, and Depth (CTD) measurements in the 2010 Arafura and Timor Seas Ecosystem Action Program (ATSEA). The water masses stratification was determined by calculating the temperature and salinity gradient per one meter depth, the type of water masses was determined by the T-S diagrams, and the contribution of each type of water masses is known from the Optimum Multi Parameter (OMP) analysis. The results showed that there are three water masses layers in the Timor Sea, namely the mixed layer, thermocline and halocline, and the deep layer; and two layers in the Arafura Sea are the mixed layer and the thermocline and halocline. There are 6 types of water masses identified in the Timor Sea with its contributions as follows; in the mixed layer there are Halmahera – Misool Water (HMW) contributing around 40 – 70% and Seram – Banda Water (SBW) contributing around 50 – 60%; in the thermocline layer there are Southern Subtropical Lower Water (SSLW) contributing around 30 – 40% and Indonesian Upper Water (IUW) contributing around 40 – 50%, and in the deep layer there are Austral Asian Intermediate Water (AAMW) contributing around 100% and Antartic Intermediate Water (AAIW) contributing around 20 – 70%. In the Arafura Sea, 2 types of water masses were identified with its contribution as follows; Halmahera – Misool Water (HMW) contributing around 30 – 50% and Seram – Banda Water (SBW) contributing around 100%.

Keywords
Stratification; water masses; ATSEA 2010; Timor Sea; Arafura Sea.

Topic
Coastal and Ocean Dynamics

Link: https://ifory.id/abstract/dYbwGkNxDLPq

Corresponding Author
Iqbal Ardiansyah

Institutions
a) Study Program of Earth Science, Faculty of Earth Sciences and Technology, Bandung Institute of Technology
b) Research Group of Oceanography, Faculty of Earth Sciences and Technology, Bandung Institute of Technology
*nining[at]fitb.itb.ac.id

Abstract
Significant Wave Height (SWH) in Natuna Waters has been simulated during Typhoon Hagibis event in the period of 20th – 27th November 2007 in the South China Sea by using Simulating WAve Nearshore (SWAN) model with 1/24° spatial resolution. 1/4° wind data obtained from Cross-Calibrated Multi-Platform (CCMP) and 1/120° bathymetry data derived from General Bathymetry Chart of the Ocean (GEBCO) are used as model input. Open boundary values for the SWAN simulation are obtained from WAVE WATCH III (WW3) results, which are provided by Indonesian Geospatial Information Agency (BIG). The model results show that swell generated by Typhoon Hagibis arrived in the Natuna Waters after 3-day travel time, which is 23rd November 2007. Typhoon Hagibis has an impact on swell propagation from the South Cina Sea to the Natuna Waters. SWH in the Natuna Waters during the peak phase of Typhoon Hagibis and Mitag (23rd November 2007) vary between 0.8 – 3.5 m. There are 6 observation points in the study area to investigate SWH variation from 22nd October – 22nd December 2007. Point 1 (P1), Point 3 (P3) and Point 5 (P5) show points in the northern part of the Natuna island, Subi Besar Islands and Riau Islands, respectively. Meanwhile, Point 2 (P2), Point 4 (P4) and Point 6 (P6) show points in the southern part of the Natuna island, Subi Besar Islands and Riau Islands, respectively. Typhoon Hagibis in the peak phase generates the SWH at P1, P3, and P5 of about 0.6 – 2.5 m and generates the SWH at P2, P4, and P6 of about 0. 5 – 1.6 m.

Keywords
Significant Wave Height, Typhoon Hagibis, Natuna Waters, SWAN

Topic
Coastal and Ocean Dynamics

Link: https://ifory.id/abstract/zthjmcdpTv8W