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All Journal Jurnal Ilmu dan Teknologi Kelautan Tropis Journal of Oceanography BULLETIN OF THE MARINE GEOLOGY Journal of Coastal and Ocean Sciences Jurnal Hidrografi Indonesia Journal of Fisheries & Marine Journal Of Sustainable Education (JOSE)
Firdaus, Randi
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Agriculture, Biological Sciences & Forestry Biochemistry, Genetics & Molecular Biology Decision Sciences, Operations Research & Management Earth & Planetary Sciences Education Environmental Science Immunology & microbiology Library & Information Science Physics Other

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KARAKTERISTIK MASSA AIR LAPISAN TERCAMPUR DAN LAPISAN TERMOKLIN DI SELAT LOMBOK PADA BULAN NOVEMBER 2015 Firdaus, Randi; Setiyono, Heryoso; Harsono, Gentio
Journal of Oceanography Vol 5, No 4 (2016)
Publisher : Program Studi Oseanografi, Jurusan Ilmu Kelautan, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (470.188 KB)

Abstract

Penelitian ini bertujuan untuk mengetahui karakteristik massa air di lapisan tercampur dan lapisan termoklin. Karakteristik yang dimaksud adalah suhu, salinitas, densitas, stabilitas statik dan tipe massa air.Penelitian ini menggunakan data suhu, salinitas, densitas dan kedalaman yang diakuisisi dari instrumen CTD. Data suhu dan salinitas digunakan untuk menentukan tipe massa air dengan diagram T-S (Temperatur-Salinitas) yang mengacu pada klasifikasi Wyrtki, sedangkan data densitas dan kedalaman digunakan untuk menentukan stabilitas statik massa air. Stratifikasi massa air ditentukan dengan dengan kriteria ambang lapisan piknoklin >0,125 kg/m3 dari densitas permukaan dan lapisan termoklin >0,5oC dari suhu permukaan. Hasil penelitian menunjukkan adanya stratifikasi lapisan massa air bervariasi secara vertikal dengan kedalaman lapisan tercampur bervariasi dari 0-43 m berdasarkan temperatur dan 0-45 m berdasarkan densitas, lapisan termoklin berada diantara kedalaman 3-412 m. Stabilitas massa air menunjukkan nilai bervariasi dari -15 sampai 30 siklus/jam, nilai Frekuensi Brunt-Vӓїsӓlӓ yang tinggi ditemukan di lapisan termoklin. Hasil diagram T-S menunjukkan adanya empat  massa air yang teridentifikasi yaitu massa air North Pacific Intermediate Water (NPIW) yang dicirikan salinitas minimum, massa air North Pacific Subtropical Water (NPSW) dengan karakter salinitas maksimum, massa air North Indian Subtropical Water (NISW) dicirikan salinitas maksimum dan massa air Australasian Mediterranean Water (AAMW) yang dicirikan oleh salinitas maksimum. 
Distribution of Sea Surface Temperature and Salinity in the Karimata Strait Yuliardi, Amir Yarkhasy; Firdaus, Randi; Heltria, Septy; Prayogo, Luhur Moekti; Nugroho, Agung Tri; Rahmalia, Diah Ayu; Sari, Ratna Juita
Journal of Coastal and Ocean Sciences Vol. 6 No. 1 (2025): January
Publisher : Department of Marine Science, Faculty of Fisheries and Marine Universitas Riau

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31258/jocos.6.1.10-15

Abstract

The Karimata Strait possesses unique characteristics influenced by its geographical location and the local, regional, and global impacts on its physical, biological, and chemical parameters, contributing to its potential as a significant fishing ground. This study aims to observe and analyze the physical oceanographic parameters, including temperature, salinity, and sea surface currents, within the Karimata Strait. The dataset comprises monthly averaged data, resulting in a single representative value for each month. Key physical parameters examined include temperature, salinity, and the horizontal (u) and vertical (v) current components. The patterns of sea surface temperature (SST) and salinity distribution in the Karimata Strait exhibit significant variations between the west and east monsoons. During the west monsoon season, the South China Sea influenced the region with lower SST and higher salinity than the Java Sea. In contrast, the east monsoon demonstrates an inverse pattern with warmer, fresher waters from the Java Sea moving towards the strait. Additionally, the horizontal distribution of these parameters highlights the critical role of sea currents in dispersing physical oceanographic characteristics within the region. These findings underscore the dynamic nature of the Karimata Strait's oceanography, influenced by seasonal monsoon shifts, water masses from adjacent seas, and freshwater inputs from rivers, crucial for understanding the broader Indonesian Throughflow (ITF) system and its implications for regional climate and marine ecosystems.
Distribution of Sea Surface Temperature and Salinity in the Karimata Strait Yuliardi, Amir Yarkhasy; Firdaus, Randi; Heltria, Septy; Prayogo, Luhur Moekti; Nugroho, Agung Tri; Rahmalia, Diah Ayu; Sari, Ratna Juita
Journal of Coastal and Ocean Sciences Vol. 6 No. 1 (2025): January 2025
Publisher : Department of Marine Science, Faculty of Fisheries and Marine Universitas Riau

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31258/jocos.6.01.10-15

Abstract

The Karimata Strait possesses unique characteristics influenced by its geographical location and the local, regional, and global impacts on its physical, biological, and chemical parameters, contributing to its potential as a significant fishing ground. This study aims to observe and analyze the physical oceanographic parameters, including temperature, salinity, and sea surface currents, within the Karimata Strait. The dataset comprises monthly averaged data, resulting in a single representative value for each month. Key physical parameters examined include temperature, salinity, and the horizontal (u) and vertical (v) current components. The patterns of sea surface temperature (SST) and salinity distribution in the Karimata Strait exhibit significant variations between the west and east monsoons. During the west monsoon season, the South China Sea influenced the region with lower SST and higher salinity than the Java Sea. In contrast, the east monsoon demonstrates an inverse pattern with warmer, fresher waters from the Java Sea moving towards the strait. Additionally, the horizontal distribution of these parameters highlights the critical role of sea currents in dispersing physical oceanographic characteristics within the region. These findings underscore the dynamic nature of the Karimata Strait's oceanography, influenced by seasonal monsoon shifts, water masses from adjacent seas, and freshwater inputs from rivers, crucial for understanding the broader Indonesian Throughflow (ITF) system and its implications for regional climate and marine ecosystems
Pengaruh Reward Terhadap Prestasi Belajar Siswa Di SD Swasta Al-Mutakinah Firdaus, Randi; Kirana, Candra
Journal of Sustainable Education Vol. 2 No. 2 (2025): Juni 2025
Publisher : EL-EMIR Institute

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.63477/jose.v2i2.164

Abstract

The purpose of this study was to determine the effect of giving rewards and the influence of rewards on students' learning interests at Al Mutakinah Private Elementary School, Imamah, Mandau District, Bengkalis Regency. This study used a qualitative approach with a descriptive research type. The qualitative approach was chosen because it aims to deeply understand the interests and learning outcomes of grade III students at Al Mutakinah Private Elementary School, Imamah, Mandau District, Bengkalis Regency. This approach also allows researchers to obtain richer and more detailed information through interviews, observations, and documentation that describe social reality naturally. This descriptive study focuses on describing students' conditions and how they affect their learning interests. Based on the results of the study on the effect of giving rewards on students' learning interests at Al Mutakinah Private Elementary School, Imamah, Mandau District, Bengkalis Regency, the following conclusions can be drawn: Planned and Varied Rewards, Rewards given by the school, such as certificates, medals, praise, and the opportunity to choose activities, have a positive influence on students' learning interests. This reward is one way to appreciate students' achievements and behavior, thus encouraging them to be more active in learning activities. Clear Reward Criteria Reward criteria that include academic achievement, positive attitudes, and student involvement in class activities, help students understand what the school expects. With these criteria, students are motivated to show their best efforts. The Right Time to Give Rewards Rewards that are given immediately after students reach their targets provide effective positive reinforcement. This increases students' learning motivation, because they feel that their efforts are directly appreciated. The Effect of Rewards on Learning Interests Giving rewards has been shown to increase students' learning interests. Students who receive rewards show higher enthusiasm in participating in learning activities, and strive to achieve better achievements in the future.  
Spatial and Temporal Variability of Mixed Layer Depth (MLD) in Eastern Indian Ocean (EIO): 1998-2020 Yuliardi, Amir Yarkhasy; Firdaus, Randi
Jurnal Ilmiah Perikanan dan Kelautan Vol. 16 No. 1 (2024): JURNAL ILMIAH PERIKANAN DAN KELAUTAN
Publisher : Faculty of Fisheries and Marine Universitas Airlangga

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20473/jipk.v16i1.44026

Abstract

Abstract Mixed Layer Depth (MLD) plays an important role in various aspects of oceanography. MLD has a characteristic parameter value that is uniform with depth. MLD has an important role for local, regional, and global phenomena. Indonesia, which is surrounded by the East Indian Ocean, will be directly influenced by the dynamics of MLD. This study aimed to analyze seasonal variability and MLD between years. Mixed layer depth data from the ARMOR3D Dataset Copernicus-Marine Environment Monitoring Service was used for MLD analysis with a threshold of 0.2oC for temperature. Wavelet analysis showed that MLD variability in the eastern Indian Ocean spans from intra-seasonal to interannual scales. Time series analysis showed a complex relationship between MLD and SST in the annual and interannual periods which indicates a different process. The MLD monthly climatology at point 90E, 0 showed the depth of mixed layers is deeper during the east monsoon (JJA-SON) ranging from 50-65 m compared to the west monsoon (DJF-MAM) which has a range of 20-40 m. Spatially the MLD in the south of the equator is deeper than in the north. Interannually, MLD is heavily influenced by the Indian Ocean Dipole. MLD depth is deeper in nIOD with a maximum depth in the range of 100 m compared to pIOD. MLD with maximum depth in the strong nIOD phase is around the equator and the pIOD phase is south of the equator. The study also showed that inter-annual variability in regions around the mainland showed a stronger response. Highlight Researh ARMOR3D data has fairly good accuracy as evidenced by data validation In general, EIO is influenced by intra-seasonal, seasonal and inter-annual variability The shallowing and deepening of the MLD are strongly correlated with the wind speed associated with the annual cycle IOD has a strong role in MLD which looks significantly different, especially when nIOD and pIOD
Karakteristik Massa Air Lapisan Tercampur dan Lapisan Termoklin di Selat Lombok Pada Bulan November 2015: Water Mass Characteristics of The Mixed Layer and Thermocline Layer in The Lombok Strait in November 2015 Firdaus, Randi; Purwanto, Budi; Harsono, Gentio; Setiyono, Heryoso
Jurnal Hidrografi Indonesia Vol 4 No 1 (2022): Jurnal Hidrografi Indonesia
Publisher : Pusat Hidro-Oseanografi TNI Angkatan Laut

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.62703/jhi.v4i1.30

Abstract

Tujuan penelitian ini adalah untuk mengetahui karakteristik massa air pada lapisan campuran dan lapisan termoklin. Karakteristik massa air pada penelitian ini adalah suhu, salinitas, kepadatan, stabilitas statis dan jenis air. Penelitian ini menggunakan data suhu, salinitas, kepadatan dan kedalaman yang berasal dari CTD. Data suhu dan Salinitas digunakan untuk menentukan jenis air menggunakan diagram T-S (Temperature-Salinity) menurut klasifikasi Wyrtki sedangkan data kepadatan dan kedalaman digunakan untuk menentukan stabilitas statis. Stratifikasi massa air diklasifikasikan berdasarkan nilai ambang batas >0,125 kg/m3 dari nilai kepadatan permukaan untuk lapisan piknoklin dan >0,5°C dari nilai suhu permukaan untuk lapisan termoklin. Hasil penelitian menunjukkan lapisan massa air terstratifikasi vertikal dan kedalaman lapisan campuran bervariasi antara 0-43 m untuk klasifikasi suhu dan 0-45 m untuk klasifikasi kepadatan, lapisan termoklin terdapat pada kedalaman 3-412 m. Stabilitas statis massa air bervariasi antara -15 sampai 30 siklus/jam dan nilai yang tinggi terdapat pada lapisan termoklin. Diagram T-S menunjukkan empat jenis air yang teridentifikasi: North Pacific Intermediate Water (NPIW) yang bercirikan salinitas minimum, North Pacific Subtropical Water (NPSW), North Indian Subrtopical Water (NISW) yang bercirikan salinitas maksimum, dan Australasian Mediterranean Water (AAMW) yang bercirikan salinitas maksimum. ditandai dengan salinitas maksimum.
TIDAL HARMONIC ANALYSIS AND PREDICTION TO SUPPORT EARLY WARNING FOR COASTAL FLOODING Firdaus, Randi; Tazaroh, Nurul; Surendra, Oky; Prasetyo, Eko; Adriyanto, Riris
BULLETIN OF THE MARINE GEOLOGY Vol 39, No 1 (2024)
Publisher : Marine Geological Institute of Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32693/bomg.39.1.2024.863

Abstract

The Indonesian Maritime Continent (IMC) is the largest archipelago that vulnerable to climate change especially sea level rise. Some coastal areas frequently experience coastal flooding affecting the activities and infrastructures. Thus, an accurate tide prediction in this region plays a pivotal role in providing the early warning, mitigation, and adaptation to frequent coastal flooding. BMKG, through the Center for Marine Meteorology has done undertaken efforts to provide an accurate tidal prediction information by developing the tidal information system call the Indonesian Tidal Information System (INATIS). Tidal harmonic analysis (THA) using the least-square method was applied to sea level data from 49 Marine Automatic Weather System (MAWS) stations collected between 2020-2021 to generate tidal predictions for the period of 2022-2023. Accuracy was assessed based on Mean Absolute Error (MAE) and the Mean Absolute Percentage Error (MAPE). MAWS stations with prediction accuracy above 80% visualized on publicly accessible online platform of the BMKG website using the open-source Looker Studio. Verification of the tidal predictions showed an average prediction accuracy of 93.21% with a MAE of 0.11 m. The high accuracy of INATIS demonstrates its potential as a reference for coastal flood early warning systems.
PENCITRAAN STRUKTUR HALUS TERMOHALIN MENGGUNAKAN SEISMIK REFLEKSI MULTIKANAL DI UTARA LAUT MALUKU Manik, Henry Munandar; Atmadipoera, Agus Saleh; Zuraida, Rina; Purwanto, Catur; Firdaus, Randi
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

Abstract

Akustik frekuensi rendah seperti seismik laut yang umumnya digunakan untuk pemetaan geologi sekarang berkembang menjadi perangkat untuk memetakan kolom perairan. Penelitian ini bertujuan memetakan struktur halus termohalin (thermohaline fine structure) sepanjang lintasan seismik di Laut Maluku bagian utara. Data seismik refleksi dari 72 saluran sepanjang lintasan 239 km diproses untuk menggambarkan struktur kolom perairan di Laut Maluku. Penampang seismik oseanografi menunjukkan dengan jelas adanya reflektor pada kedalaman 400 m dan 800 m yang merupakan batas bawah lapisan termoklin musiman dan termoklin permanen. Di antara kedalaman 400 - 800 m terdapat refleksi yang disebabkan oleh perundakan termohalin (thermohaline staircase) seperti yang terkonfirmasi oleh data CTD. Data seismik kolom perairan memperlihatkan adanya struktur seperti gelombang internal di bagian barat laut ambang Tufure dengan tinggi dan panjang gelombang berturut-turut sekitar 102 m dan 17 km. Amplitudo seismik di kolom perairan menunjukkan kesesuaian dengan kontras vertikal parameter fisika oseanografi seperti suhu, salinitas, dan kecepatan suara. Refleksi di kolom perairan bisa disebabkan oleh kontras gradient suhu berkisar antara 0,03°C/m hingga >0,20°C/m. Impedansi akustik pada zona target berkisar antara 0,8 × 106 kg/m3 m/s hingga 2,06 × 106 kg/m3 m/s. Penelitian ini mengungkap bahwa data seismik kolom perairan bisa bermanfaat untuk mempelajari karakteristik kolom perairan di Laut Maluku bagian utara.
Co-Authors Adriyanto, Riris Agus Atmadipoera Amir Yarkhasy Yuliardi Budi Purwanto Candra Kirana Catur Purwanto, Catur Eko Prasetyo Gentio Harsono Henry Munandar Manik Heryoso Setiyono Luhur Moekti Prayogo Nugroho, Agung Tri Rahmalia, Diah Ayu Rina Zuraida Sari, Ratna Juita Septy Heltria Surendra, Oky Tazaroh, Nurul