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All Journal Jurnal Ilmu dan Teknologi Kelautan Tropis ILMU KELAUTAN: Indonesian Journal of Marine Sciences Jurnal Geologi Kelautan: Media Hasil Penelitian Geologi Kelautan

Agus S. Atmadipoera

Departemen Ilmu Dan Teknlogi Kelautan, FPIK-IPB, BogorInstitut Pertanian Bogor

Author-ID : 2891071

Biochemistry, Genetics & Molecular Biology Decision Sciences, Operations Research & Management Earth & Planetary Sciences Library & Information Science

Published : 12 Documents Claim Missing Document

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CHARACTERISTICS AND VARIABILITY OF THE FLORES ITF AND ITS COHERENCE WITH THE SOUTH JAVA COASTAL CURRENT Agus S. Atmadipoera; Paradita Hasanah
Jurnal Ilmu dan Teknologi Kelautan Tropis Vol. 9 No. 2 (2017): Elektronik Jurnal Ilmu dan Teknologi Kelautan Tropis
Publisher : Department of Marine Science and Technology, Faculty of Fisheries and Marine Science, IPB University

Characteristics and transport variability of the Indonesian Throughflow (ITF) in the western Flores Sea (FS) and its coherency with the South Java Coastal Current (SJCC) fluctuation are investigated using validated ocean general circulation model output (2008-2014) from the INDESO configuration. The results show that near-surface circulation in the study area is characterized by two distinct regimes: strong southwestward ITF flow and quasi-transient anti-cyclonic eddies. Vertical dimension of ITF crossing 7.5°S is about 112 km width, 250 m depth, and high velocity core at thermocline >0.3 m/s. Transport volume estimates along this latitude is -4.95 Sv (southward). Bifurcation of ITF flow appears north offshore Lombok Island where -2.92 Sv flowing into Lombok Strait and the rest flowing eastward into FS. Meanwhile, vertical dimension of SJCC crossing 114°E is about 89 km width, 120 m depth, and high velocity core at sub-surface >0.35 m/s. Mean transport of SJCC is +2.65 Sv. Coherency between Flores ITF and SJCC transport variability on intra-seasonal scales is significantly high, e.g., on 30 day period (coher=0.92) and phase-lags of 0.6-day with SJCC leading to Flores ITF. This result confirmed previous studies, related to intrusion of coastally trapped Kelvin waves into Flores Sea via Lombok Strait. Keywords: Indonesian Throughflow, western Flores Sea, South Java Coastal Current

GENETIC DIVERSITY OF OLIVE RIDLEY Lepidochelys olivacea ASSOCIATED WITH CURRENT PATTERN IN CENDRAWASIH BAY, PAPUA Samsul Bahri; Agus S. Atmadipoera; Hawis H. Madduppa
Jurnal Ilmu dan Teknologi Kelautan Tropis Vol. 9 No. 2 (2017): Elektronik Jurnal Ilmu dan Teknologi Kelautan Tropis
Publisher : Department of Marine Science and Technology, Faculty of Fisheries and Marine Science, IPB University

Cendrawasih Bay is habitat for olive ridley (Lepidochelys olivacea) which is directly adjacent to the Pacific Ocean. The presence and the diversity of L. olivacea in Cendrawasih Bay has been threatened. Genetics can be the key to conservation because they play an important role in maintaining population and recovering from damage. This study aims to determine the genetic diversity of L. olivacea and its association to the current pattern in the waters of Cendrawasih Bay. Samples of L. olivacea (n=20) were collected in Kwatisore (n=8) and Yapen Island (n=12) in Cendrawasih Bay waters from August 2015 to December 2016. The molecular analysis was based on 791-bp fragment of D-Loop on the non-coding region gen. The current pattern analysis was performed through INDESO data and visualized by using Ferret software. Phylogenetic analysis showed that 2 groups of L. olivacea from a total of 2 haplotypes, whose population from Kwatisore was dispersed in two haplotypes, while the population from Yapen Island was only dispersed in one haplotype. Populations from Kwatisore showed higher variations than populations from Yapen Island. The current pattern analysis suggests that the two study sites, Kwatisore and Yapen islands are different. Both populations are only connected by the Northwest monsoon currents period that indicates a little geneflow between this populations. Thus causing differences variation between Kwatisore and Yapen Island populations genetically. Keywords: genetic diversity, current pattern, coral triangle, olive ridley

RANCANG BANGUN DAN UJI KINERJA WAVE BUOY SEBAGAI ALAT PENGUKUR TINGGI GELOMBANG PESISIR Erik Munandar; Indra Jaya; Agus S Atmadipoera
Jurnal Ilmu dan Teknologi Kelautan Tropis Vol. 10 No. 1 (2018): Jurnal Ilmu dan Teknologi Kelautan Tropis
Publisher : Department of Marine Science and Technology, Faculty of Fisheries and Marine Science, IPB University

Gelombang di laut memiliki pergerakan yang acak dan komplek, sehingga tinggi dan periode gelombang sulit untuk diukur dan dirumuskan secara akurat. Wahana terapung seperti wave buoy dengan sensor percepatan telah banyak digunakan untuk mengukur gelombang permukaan. Penelitian ini bertujuan merancang dan membuat wave buoy sederhana sebagai pengukur tinggi gelombang di perairan pantai serta menguji coba kinerja alat yang dihasilkan pada skala laboratorium dan skala lapang, sehingga alat yang dihasilkan mampu bekerja dengan baik. Hasil perhitungan terhadap dimensi atau ukuran buoy diperoleh nilai metasentrum sebesar 2,5 dimana hal ini menunjukkan bahwa wahana pelampung stabil. Selain itu, perbedaan kecepatan pada uji coba di laboratorium berhasil diperoleh gelombang yang memiliki dua frekuensi yang berbeda, dengan galat pengukuran yang diperoleh sebesar 0,01-0,07 m dengan periode yang terukur sebesar. Kinerja alat yang dilakukan di Teluk Palabuhan Ratu diperoleh beberapa tipe gelombang yang dihasilkan. Pengujian selama 24 jam diperoleh 4 periode yang signifikan yang terbagi ke dalam tiga kelompok gelombang yakni periode 1 detik, 3,37 detik kelompok gelombang angin, 1,20 jam kelompok gelombang variasi angin dan 12 jam kelompok gelombang pasang surut. Alat yang dihasilkan dapat berfungsi dengan baik mampu menyimpan data, memiliki nilai akurasi yang tinggi dapat merekam gelombang dengan periode kecil hingga periode besar.

DISIPASI ENERGI KINETIK PASANG SURUT BAROTROPIK DAN BAROKLINIK DI LAUT SULAWESI Hadi Hermansyah; Dwiyoga Nugroho; Agus Saleh Atmadipoera; Tri Prartono; Indra Jaya; Fadli Syamsudin
Jurnal Ilmu dan Teknologi Kelautan Tropis Vol. 10 No. 2 (2018): Jurnal Ilmu dan Teknologi Kelautan Tropis
Publisher : Department of Marine Science and Technology, Faculty of Fisheries and Marine Science, IPB University

Laut Sulawesi merupakan salah satu jalur penting perlintasan Arus Lintas Indonesia (Arlindo) yang memiliki energi pasang surut internal yang kuat. Arus pasang surut tinggi yang berinteraksi dengan topografi yang kasar akan menciptakan gelombang internal yang kuat. Disipasi dari pasang surut internal akan menyebabkan terjadinya percampuran yang akan memberikan efek penting untuk sistem perubahan iklim dan sumber daya laut. Tujuan dari penelitian ini adalah untuk mengkuantifikasi dinamika dan energetik gelombang internal di Laut Sulawesi dengan pendekatan pemodelan laut tiga dimensi NEMO. Hasil penelitian menunjukkan bahwa gelombang internal dibangkitkan pada daerah Kepulauan Sulu dan Sangihe-Talaud dengan nilai konversi energi lebih dari 10-3Wm-2 dan berpropagasi masuk ke area basin Laut Sulawesi. Disipasi energi yang terjadi pada pusat pembangkitan berkisar 10,8 GW dan berpopagasi pada area dekat pusat pembangkitan dan area basin Laut Sulawesi. Sekitar 25% (5 GW) didisipasi terjadi dekat pusat pembangkitan, peningkatan disipasi energi baroklinik terjadi pada saat gelombang internal berpopagasi menjauhi daerah pusat pembangkitan dengan nilai yang bervariasi antara 1,4 sampai 4,8 GW. Daerah dengan jarak 36 km sampai 54 km terjadi penurunan disipasi energi baroklinik, signal yang kuat dari Kepulaun Sangihe-Talaud berangsur menurun pada saat propagasi dari 10-2sampai 10-3W/m2.

KARAKTERISTIK UPWELLING DI PERAIRAN SELATAN JAWA PADA TAHUN STRONG LA NINA 2010 DAN SUPER EL NINO 2015 Agus S. Atmadipoera; Agitha S. Jasmine; Mulia Purba; Anastasia R.T.D. Kuswardani
Jurnal Ilmu dan Teknologi Kelautan Tropis Vol. 12 No. 1 (2020): Jurnal Ilmu dan Teknologi Kelautan Tropis
Publisher : Department of Marine Science and Technology, Faculty of Fisheries and Marine Science, IPB University

Seasonal coastal upwelling in the Southern Java waters is considered to be modulated by interannual ocean-atmosphere variability of El Nino Southern Oscillation (ENSO). This study aims to investigate a contrast in seasonal upwelling characteristics during the La Nina 2010 and El Nino 2015 events, by using multi-datasets from INDESO model output and satellite-derived datasets. Distinct characteristics of seasonal upwelling was clearly seen. In La Nina, surface ocean-atmosphere variables were much lower than that observed in El Nino, except for precipitation rate, sea surface temperature, and sea surface height. In La Nina, warmer (27-28°C) and a very freshwater (<33.80psu) were predominant in the upper 45m depth, concealing upwelling cooler water at subsurface. In contrast, in the El Nino, a drastic upwelled subsurface water of isotherms of 25-26°C and isohalines of 34.24-34.44psu were outcropped at the sea surface. Temperature-based upwelling index is -2°C and +4°C, demonstrating the ENSO has strongly modulated the upwelling intensity. A strong eastward South Java Coastal Current (SJCC) was found only in La Nina event. Persistent westward Indonesian Throughflow south of 9.5°S were visible both in different ENSO events. Estimate of Ekman transport derived from model meridional current was intervened strongly by the presence of the SJCC and the ITF.

STRUKTUR VERTIKAL DAN VARIABILITAS ARLINDO YANG MASUK KE TEPI BARAT LAUT BANDA La Ode M. Gunawan Giu; Agus S. Atmadipoera; Yuli Naulita; Dwiyoga Nugroho
Jurnal Ilmu dan Teknologi Kelautan Tropis Vol. 12 No. 2 (2020): 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.v12i2.29142

Arus Lintas Indonesia (Arlindo) merupakan sistem arus antara samudera Pasifik dan Hindia yang melewati Laut Indonesia, seperti melalui jalur primer Selat Makassar ke Laut Flores dan melalui jalur sekunder Selat Lifamatola ke Laut Banda. Penelitian ini bertujuan untuk mengkaji struktur vertikal dan variabilitas Arlindo di Laut Flores Timur (Flores) dan Laut Banda Utara (Banda) yang berasal dari keluaran model laut INDESO antara tahun 2008 dan 2014. Analisis struktur Arlindo dengan menghitung rataan komponen arus secara vertikal. Volume transpor dihitung dari penampang di Laut Banda dan Laut Flores. Deret waktu Arlindo dianalisis variabilitasnya menggunakan filter band-pass dan transformasi wavelet kontinu. Hasil penelitian menunjukkan bahwa Arlindo Banda secara dominan mengalir ke selatan, sedangkan Arlindo Flores mengalir ke timur di sepanjang utara Kepulauan Nusa Tenggara. Struktur vertikal aliran Arlindo mengalami penguatan di kedalaman antara 50 m dan 150 m. Perkiraan total volume transpor selama periode 7 tahun dari kedua jalur Arlindo yang masuk ke Laut Banda bagian barat sebesar 6,27 Sv (±3,81 Sv), yang merupakan kesepakatan baik dengan studi model sebelumnya. Variasi tahunan transpor Arlindo Banda (Flores) maksimum selama musim Barat Laut (Tenggara) dan minimum selama musim Tenggara (Barat Laut). Variabilitas yang mendominasi pada transpor Arlindo Banda ialah periode intra-musiman (ISV) dan semi-tahunan (SAV), sedangkan variabilitas transpor Arlindo Flores didominasi oleh periode tahunan (AV).

RESPONS SUHU PERMUKAAN LAUT DAN KLOROFIL-A TERHADAP KEJADIAN ENSO DAN IODM DI WILAYAH INDO-PASIFIK TROPIS Andry Purnama Putra; Agus S. Atmadipoera; John I. Pariwono
Jurnal Ilmu dan Teknologi Kelautan Tropis Vol. 12 No. 1 (2020): Jurnal Ilmu dan Teknologi Kelautan Tropis
Publisher : Department of Marine Science and Technology, Faculty of Fisheries and Marine Science, IPB University

The interannual ocean-atmosphere anomaly of the El Nino Southern Oscillation (ENSO) and Indian Ocean Dipole Mode (IODM) events that prevail in the tropical Indo-Pacific region impacts significantly on regional marine ecosystem, hydrology and climate variabilities. This study aims to investigate spatial pattern and temporal variability of sea surface temperature (SST) and surface chlorophyll-a (Chl-a), related to ENSO and IODM in the region. The monthly data time-series (1980-2017) were obtained from global data center, and were analyzed by applying the empirical orthogonal function (EOF) methods. The results show that the first three eigen values of SST (Chl-a) explained for 81.7% (76%) of total variance. Spatial pattern of SST EOF mode-1 (56%) formed an asimetric dipole-like shape between eastern and western tropical Pacific with a distinct pattern in upwelling region off Peru waters. This pattern may be associated with 'normal' or La Nina events. Furthermore, El Nino and IODM condition may be depicted from SST mode-2 (19%), in which negative phase contours were predominant over equatorial Pacific and disappearing 'upwelling region' off Peru waters.

PENCITRAAN STRUKTUR HALUS TERMOHALIN MENGGUNAKAN SEISMIK REFLEKSI MULTIKANAL DI UTARA LAUT MALUKU Randi Firdaus; Henry Munandar Manik; Agus Saleh Atmadipoera; Rina Zuraida; Catur Purwanto
Jurnal Ilmu dan Teknologi Kelautan Tropis Vol. 13 No. 1 (2021): 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.v13i1.32346

Low-frequency acoustic such as marine seismic that has been commonly used in geological mapping is nowadays being developed as tools to map the water columns. This study aims to map thermohaline fine structure in the Northern Maluku Sea. Seismic reflection data from 72 channel along 239 km track line was processed to delineate water column structure. The depth-distance seismic oceanography section clearly showed reflectors at depth of 400 m and 800 m correspond to lower boundary of the seasonal and permanent thermocline layers, respectively. The reflections between depth of 400 m and 800 m were caused by the thermohaline staircase as confirmed by CTD data. Water column reflections showed the presence of internal wave-like structure in the northwestern Tufure sill which has height and wavelength about 102 m and 17 km, respectively. The seismic amplitude in the water column corresponded to the vertical contrast of physical oceanographic parameters such as temperature, salinity, and sound speed. Reflections in the water column could be caused by temperature gradients ranging contrast from 0.03°C/m to >0.20°C/m. The acoustic impedance in the internal wave-like zone was ranging from 0.8 x 106 kg/m3 m/s to 2.06 x 106 kg/m3 m/s. This research revealed that the marine seismic data can be useful for studying the water column characteristics in the Northern Maluku Sea.

Analysis of Characteristics and Turbulent Mixing of Seawater Mass in Lombok Strait Amir Yarkhasy Yuliardi; Agus S. Atmadipoera; Gentio Harsono; Nyoman Metta N. Natih; Kentaro Ando
ILMU KELAUTAN: Indonesian Journal of Marine Sciences Vol 26, No 2 (2021): Ilmu Kelautan
Publisher : Marine Science Department Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ik.ijms.26.2.95-109

The Lombok Strait, as one of the outlet straits, is part of the ITF route, which is directly adjacent to the Indian Ocean. There is a sill in the Lombok Strait, which is a place for internal wave generation. Leg-1 data from the Japan Agency for Marine-Earth Science and Technology in collaboration with the Agency for the Assessment and Application of Technology which is part of the Tropical Ocean Climate Study Expedition including CTD Yoyo and ADCP taken using ship vehicles R/V Kaiyo. CTD Snapshot from PUSHIDROSAL using the KRI Spica 934 vehicle part of the Opssurta Baruna Jaya 2 Expedition. Determination of seawater mass stratification with the criteria for the thermocline layer is ≥ 0.05 °C.m-1. Four types of water masses were identified, Java Sea, mixed seawater mass (Java Sea - ITF) which occurred diapycnal mixing, North Pacific Subtropical Water (NPSW) and North Pacific Intermediate Water (NPIW). The seawater mass stratification in the Lombok Strait based on temperature, salinity and density which are seen to follow the internal tidal pattern. The average values for energy dissipation and vertical diffusivity for each layer and replication were 5.73 x 10-7 W.Kg-1 and 3.67 x 10-2 m2.s-1 for CTD Yoyo and 2.25 x 10-6 W.Kg-1 and 7.38 x 10-2 m2.s-1 for CTD Snapshot. The value obtained is greater than the open ocean and straits in other studies. The high shear value confirms this in the thermocline layer. The Richardson gradient value> 0.25 is relatively constant in the thermocline layer.

Distribusi Percampuran Turbulen di Perairan Selat Alor (Distribution of Turbulence Mixing in Alor Strait) Adi Purwandana; Mulia Purba; Agus S Atmadipoera
ILMU KELAUTAN: Indonesian Journal of Marine Sciences Vol 19, No 1 (2014): Ilmu Kelautan
Publisher : Marine Science Department Diponegoro University

Selat Alor merupakan kanal terdalam setelah Selat Ombai di kepulauan Alor. Kontribusinya sebagai salah satu celah keluar Arus Lintas Indonesia (Arlindo) belum banyak dikaji hingga saat ini. Selat Alor memisahkan Laut Flores dan Laut Sawu, dan memiliki sill yang tinggi di dalamnya, diduga turbulensi akibat interaksi antara aliran selat dengan topografi dasar dapat memicu percampuran dan memodifikasi properti massa air yang melaluinya. Tujuan dari penelitian ini adalah untuk mengkuantifikasi transformasi massa air yang melalui Selat Alor dan mengkaji kemungkinan percampuran di dalam selat berdasarkan estimasi sesaat properti percampuran, yakni percampuran turbulen menggunakan metode skala Thorpe. Penurunan CTD dilakukan di 15 stasiun di perairan Selat Alor. Diperoleh hasil bahwa kontur kedalaman yang menghubungkan Laut Flores dengan Laut Sawu adalah ~300 m pada kanal utama. Salinitas maksimum massa air Subtropis Pasifik Utara (NPSW) dar i Laut Flores di Selat Alor banyak mengalami reduksi akibat intensifnya percampuran yang diduga dipicu oleh topografi dasar dan aliran selat yang menghasilkan turbulensi. Lapisan salinitas maksimum Massa Air Subtropis Samudera Hindia Utara (NISW) pada σθ = 23,5-24,5 terdeteksi di bagian selatan selat (Laut sawu). Jejak massa air NISW menurun dan banyak tereduksi mendekati pintu selatan selat. Intrusi Massa Air Lapisan Menengah Samudera Hindia Utara (NIIW) juga dijumpai di lapisan bawah Laut Sawu, konsisten dengan profil arus pada lapisan bawah. Rata-rata nilai difusivitas vertikal eddy (Kρ) di Selat Alor bagian utara memiliki orde of 10-3 m2 s-1, dan di bagian selatan memiliki orde bervariasi, 10-6-10-4 m2 s-1. Penyempitan celah Selat Alor diduga merupakan pemicu turbulensi tinggi aliran yang berkontribusi pada tingginya nilai difusivitas vertikal. Kata kunci: Arlindo, percampuran turbulen, difusivitas vertikal, Selat Alor Alor Strait is the deepest channel in Alor islands after Ombai Strait. Contribution of the strait as one of the secondary exit passages of Indonesian Throughflow (ITF) has not been studied yet. The strait separates Flores Sea and Sawu Sea, and is featured by the existence of high sill within the strait, suggested that turbulence due to interaction between strait flow and bottom topography could drive mixing and then modify the water mass properties. The purpose of this study is to investigate transformation of ITF water mass and turbulent mixing process with Thorpe scale method. A hydrographic survey has been carried out in July 2011, in which 15 CTD casts were lowered in the strait. The results show that Alor sill depth is about 300 ms in the main gate. Maximum salinity of NPSW from Flores Sea within Alor Strait is significantly reduced due to strong mixing, perhaps driven by bottom topography and strait flow which creates turbulence. NISW (Northern Indian Subtropical Water) with maximum salinity layer at σθ = 23,5-24,5 is dominant in the southern part of Alor Strait (i.e. Sawu Sea). The existence of NIIW (North Indian Intermediate Water) is also found in the deeper layer of Sawu Sea. The average value of vertical eddy diffussivity (Kρ) estimate in the thermocline layer and deep layer in northern part and central part of strait channel is within the order of 10-3 m2 s-1. Lower order of Kρ in the thermocline layer and deep layer were found in southern part of the Strait (Sawu Sea), ranging from 10-6 to 10-4 m2 s-1. These indicate that the existence of sills in the northern part and central part of Alor Strait could drive mixing significantly. Narrowing passage of Alor Strait probably contribute to the high value of vertical eddy diffusivity due to highly turbulence flow. Keywords: Indonesian Throughflow (ITF), turbulent mixing, vertical diffussivity, Alor Strait

Co-Authors . Apriansyah Adi Purwandana Agitha S. Jasmine Amir Yarkhasy Yuliardi Anastasia R.T.D. Kuswardani Andry Purnama Putra Catur Purwanto Dwiyoga Nugroho Dwiyoga Nugroho Dwiyoga Nugroho Fadli Syamsudin Gentio Harsono Hadi Hermansyah Hawis H Madduppa Henry M. Manik Indra Jaya Indra Jaya John I. Pariwono Kentaro Ando La Ode M. Gunawan Giu Mohd. Fadzil Akhir Mulia Purba Mulia Purba Munandar, Erik Nyoman M N Natih Paradita Hasanah Randi Firdaus Rina Zuraida Rina Zuraida Samsul Bahri Tri Prartono Yani Permanawati Yuanpin Chang Yuli Naulita

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