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CHLOROPHYLL-A CONCENTRATIONS ESTIMATION FROM AQUA-MODIS AND VIIRS-NPP SATELLITE SENSORS IN SOUTH JAVA SEA WATERS Rayhan Nuris; Jonson Lumban Gaol; Teguh Prayogo
International Journal of Remote Sensing and Earth Sciences Vol. 12 No. 1 (2015)
Publisher : BRIN

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30536/j.ijreses.2015.v12.a2673

Abstract

This study aimed to estimate the concentration of chlorophyll-a from satellite imagery of National Polar-Orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project (NPP) in the south Java Sea waters and compare it to the concentrations of chlorophyll-a estimation result from the MODIS-Aqua satellite. NPP satellite had Visible/Infrared Imager Radiometer Suite (VIIRS) sensors which performance was same as Moderate Resolution Imaging Spectroradiometer (MODIS) sensor with a better spatial resolution. This study used daily satellite imagery of VIIRS-NPP for the period of September 2012 to August 2013. The algorithm that was used to estimate the concentration of chlorophyll-a was Ocean Color 3-band ratio (OC-3). The results showed that the spatial distribution pattern of chlorophyll-a concentration between VIIRS - NPP sensor and MODIS had the same pattern, but the estimation of chlorophyll-a concentration from the MODIS sensor was higher than VIIRS -NPP sensor. The concentration of chlorophyll-a showed that there were spatial and temporal variation in the south Java Sea waters. Generally, concentrations of chlorophyll-a was higher in East monsoon than West monsoon.
COASTAL UPWELLING UNDER THE INFLUENCE OF WESTERLY WIND BURST IN THE NORTH OF PAPUA CONTINENT, WESTERN PACIFIC Harold J.D.Waas; Vincentius P. Siregar; Indra Jaya; Jonson Lumban Gaol
International Journal of Remote Sensing and Earth Sciences Vol. 9 No. 2 (2012)
Publisher : BRIN

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30536/j.ijreses.2012.v9.a1837

Abstract

Coastal upwelling play an important role in biological productivity and the carbon cycle in the ocean. This research aimed to examine the phenomenon of coastal upwelling that occur in the coastal waters north of Papua continent under the influence of Westerly Wind Burst(WWB) prior to the development of El Nino in the Pacific. Data consisted of sea surface temperature, vertical oceanic temperature, ocean color satellite image, wind stress and vector wind speed image, sea surface high, and Nino 3.4 index. Coastal upwelling events in the northern coastal waters of Papua continent occurred in response to westerly winds and westerly wind burst (WWBs) during December to March characterizing by low sea surface temperature (SST) (25 - 28ï‚°C), negative sea surface high deviation and phytoplankton blooming, except during pre-development of the El Nino 2006/2007 where weak upwelling followed by positive sea surface high deviation. Strong coastal upwelling occurred during two WWBs in December and March1996/1997 with maximum wind speed in March produced a strong El Nino 1997/1998. Upwelling generally occurred along coastal waters of Jayapura to Papua New Guinea with more intensive in coastal waters north of Papua New Guinea indicated by Ekman transport and Ekman layer depth maximum.
GROWTH RATE AND PRODUCTIVITY DYNAMICS OF ENHALUS ACOROIDES LEAVES AT THE SEAGRASS ECOSYSTEM IN PARI ISLANDS BASED ON IN SITU AND ALOS SATELLITE DATA Agustin Rustam; Dietriech Geoffrey Bengen; Zainal Arifin; Jonson Lumban Gaol; Risti Endriani Arhatin
International Journal of Remote Sensing and Earth Sciences Vol. 10 No. 1 (2013)
Publisher : BRIN

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30536/j.ijreses.2013.v10.a1847

Abstract

Enhalus acoroides is the largest population of seagrasses in Indonesia. However, growth rate and productivity analyses of Enhalus acoroides and the use of satellite data to estimate its the productivity are still rare. The goal of the research was to analyze the growth rate, productivity rate,seasonal productivity of Enhalus acoroides in Pari island and its surroundings. The study was divided into two phases i.e., in situ measurments and satellite image processing. The field study was conducted to obtain the coverage percentage, density, growth rate, and productivity rate, while the satellite image processing was used to estimate the extent of seagrass. The study was conducted in August 2011 toJuly 2012 to accommodate all four seasons. Results showed that the highest growth rate andproductivity occurred during the transitional season from west Monsoon to the east Monsoon of 5.6cm/day and 15.75 mgC/day, respectively. While, the lowest growth rate and productivity occurred during the transition from east Monsoon to the west Monsoon of 3.93 cm/day and 11.4 mgC/day, respectively. Enhalus acoroides productivity reached its maximum during the west Monsoon at 1081.71 mgC/day/m2 and minimum during east Monsoon with 774.85 mgC/day/m2 . Based on ALOS data in 2008 and 2009, total production of Enhalus acoroides in the proximity of Pari islands reached its maximum occur during the west Monsoon (48.73 – 49.59 Ton C) and minimum during transitional season (16.4-16.69 Ton C). Potential atmospheric CO2 absorption by Enhalus acoroides in Pari island was estimated at the number 60.14 – 181.82 Ton C.
VULNERABILITY LEVEL MAP OF TSUNAMI DISASTER IN PANGANDARAN BEACH, WEST JAVA Iqoh Faiqoh; Jonson Lumban Gaol; Marisa Mei Ling
International Journal of Remote Sensing and Earth Sciences Vol. 10 No. 2 (2013)
Publisher : BRIN

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30536/j.ijreses.2013.v10.a1848

Abstract

Indonesia is located in a seismic active region where tsunami often occur. One of tsunami prone areas in Indonesia is southern coast of Java, such as the coastal areas of Pangandaran, West Java. One of the instruments in the tsunami disaster mitigation is the vulnerability map of coastal region on tsunami. Analyses of tsunami vulnerability assessment was performed by using merger or overlay methods in Geographic Information Systems (GIS). The parameters used to analyze tsunami vulnerability level were elevation, topography, landuse, coastal border, and river banks. The vulnerability were divided into five classes i.e., very high, high, medium, low, and very low. Results showed that Pananjung, Babakan, Pangandaran (Pangandaran District); and Sukaresik and Cikembulan (Sidamulih District) sub-districts were identified as areas of very high level of tsunami vulnerability with total area of 737.703 hectares. Areas with low level of vulnerability were Pagergunung, Putrapinggan, and Kersaratu sub-districts with total area of 4,816.204 hectares.
Comparing Vessel Monitoring System and Logbook Data for Skipjack Tuna Habitat Modeling in Eastern Indian Ocean Nurzeha, Ridwan; Gaol, Jonson Lumban; Agus, Syamsul Bahri; Alam, Al Fajar
Jurnal Perikanan Universitas Gadjah Mada Vol 27, No 2 (2025)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jfs.107568

Abstract

Skipjack tuna (Katsuwonus pelamis) is important to Indonesian fisheries, which lead to the need of accurate habitat prediction for sustainable management. This study assesses the spatiotemporal coverage and predictive utility of logbook and Vessel Monitoring System (VMS) data for skipjack habitat modeling using MaxEnt, with sea surface temperature (SST), chlorophyll-a, sea surface height (SSH), and salinity as predictors. Findings indicate VMS offers broader positional coverage but suffers from behavioral ambiguity, whereas logbook data, though spatially limited, provides higher accuracy due to direct catch reporting. Model evaluations showed comparable performance: the VMS-derived model achieved an AUC of 0.760 and an F1-score of 0.658, while the logbook-derived model yielded an AUC of 0.742 and an F1-score of 0.624. However, distribution analysis revealed the logbook-derived model performed better, with 87.5% of fishing events occurring in higher Habitat Suitability Index (HSI) areas compared to 73.1% for the VMS-derived model. These results suggest VMS data presents a viable alternative and comparative data source to logbook records for habitat modeling, offering opportunities to enhance fisheries management.
Characteristics of Sediment Grain Size in Shallow Waters of Kapota Island and Atoll, Wakatobi Baigo Hamuna; Sri Pujiyati; Jonson Lumban Gaol; Totok Hestirianoto; Alianto Alianto
Jurnal Ilmu dan Teknologi Kelautan Tropis Vol 18 No 2 (2026): Jurnal Ilmu dan Teknologi Kelautan Tropis
Publisher : Department of Marine Science and Technology, Faculty of Fisheries and Marine Science, IPB University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29244/jitkt.18.2.72360

Abstract

Shallow waters in tropical island and atoll regions are highly dynamic environments where sediment grain size characteristics and distribution are influenced by complex interactions. This research aims to obtain a description of the grain size characteristics of shallow water sediments on Kapota Island and Kapota Atoll, Wakatobi. Shallow water sediment samples were collected using a core pipe at 14 observation stations representing both study locations. Sediment grain size analysis was performed using the dry sieving method, while the fraction composition, sediment texture, and statistical parameters were determined with the aid of Gradistat software. The analysis results show that the shallow water sediments at both locations are composed of three main fractions: gravel (1.20–44.55%), sand (54.91–98.21%), and silt (0.01–10.50%). Texturally, sediments are classified into four types: sandy gravel, gravelly sand, slightly gravelly sand, and slightly gravelly muddy sand. The statistical parameter values indicate a mean grain size range from very coarse to very fine sand, a sorting level from moderately sorted to very poorly sorted, a skewness value from symmetrical to strongly skewed toward the coarse fraction, and a kurtosis from very flat to very peaked. Generally, there are no significant differences in the grain size characteristics of sediments between Kapota Island and Kapota Atoll, except for the sediment texture distribution pattern and the shape of the kurtosis curve. These results confirm that the sedimentation dynamics at both locations are relatively similar and provide an important basis for understanding deposition processes and managing the shallow water environment in Wakatobi.
Co-Authors . Hendrawan Achmad Fachruddin-Syah Achmad Fachrudin Syah Agnestesya Manuputty Agustin Rustam Al Hakim, Muhammad Abdul Ghofur Alam, Al Fajar Alianto , Amelius Andi Mansawan Anggi Tiarasani Ar-ridhaty Akita, Erliantina Armanda Baigo Hamuna Bambang Sadhotomo Bisman Nababan Charles Parningotan Haratua Simanjuntak Cheung, William W.L. Dendy Mahabror Dessy Berlianty Diki Zulkarnaen Djisman Manurung Domu Simbolon Dony Kushardono Dony Kushardono Dortje Theodora Silubun Ega Putra Fadli Syamsudin Fahriansyah Fahriansyah Farahdillah, Reyhanniza Ekka Fery Kurniawan Fitriani, Sarah Putri Harold J.D. Waas Harold J.D.Waas Hawis H Madduppa Herlambang Aulia Rachman Hestirianoto, Totok I Wayan Nurjaya Indra Jaya Indra Jaya Indra Jaya Iqoh Faiqoh Irawati, Febri Dwi James Parlindungan Panjaitan Jordan Tito Lubis Khairul Amri Marisa Mei Ling Marlis Yulianto Maya Eria Br Sinurat Michelia Mashita Muhammad Sudibjo Mujizat Kawaru Muklis Muklis Mukti Zainuddin Nabilla Dhani Amanda Nadela Rista Apriliya Nazal, Muhammad Faris NEVIATY PUTRI ZAMANI Noor, Hariansyah Noya, Theo Imanuel Nurmawati Nurmawati Nurzeha, Ridwan Nyoman M N Natih Rayhan Nuris Reygondeau, Gabriel Risti Endriani Arhatin Riza Aitiando Pasaribu Rizki Dimas Permana Rizty Maulida Badri Rohman, Tefur Nur Sarah Putri Fitriani Septiyan Firmansyah Setyo Budi Susilo Sri Pujiyati Suhita, Ni Putu Asri Ratna Syamsul Bahri Agus, Syamsul Bahri Teguh Prayogo Teh, Lydia van Beek, Ruben Vincentius P Siregar Widya Octavia Wildan Tino Yuli Naulita Yustie Amanda Zainal Arifin Zainal Arifin