Tren Tinggi Gelombang Laut di Wilayah Pengelolaan Perikanan (WPP) Indonesia Periode 1977–2021 (45 Tahun)

AbstrakPemahaman gelombang laut sangat penting bagi aktivitas maritim, khususnya di negara kepulauan seperti Indonesia. Pada studi ini, tren jangka panjang kecepatan angin dan tinggi gelombang signifikan (Significant Wave Height/SWH) di Wilayah Pengelolaan Perikanan (WPP) Indonesia dianalisis selama 1977–2021 (45 tahun) dengan menggunakan data dari European Centre for Medium-Range Weather Forecast (ECMWF) Reanalysis generasi kelima (ERA5). Secara keseluruhan, kecepatan angin dan SWH di perairan Indonesia mengalami kenaikan. Ratarata tren kecepatan angin dan SWH di seluruh WPP Indonesia sebesar 0,29 cm/s/tahun dan 0,19 cm/tahun. Tren jangka panjang tinggi gelombang akibat swell dan wind sea di WPP Indonesia juga mengalami kenaikan, dengan nilai rata-ratanya sebesar 0,18 dan 0,05 cm/tahun. Perairan Indonesia yang mengalami kenaikan tren kecepatan angin dan tinggi gelombang terbesar berada di WPP yang berbatasan langsung dengan laut lepas, seperti di WPP 717 (perairan utara Papua), 572 (perairan barat Sumatra), dan 573 (perairan selatan Jawa). Fenomena El NiñoSouthern Oscillation (ENSO), yakni El Niño (La Niña) berpengaruh terhadap penurunan (peningkatan) nilai kecepatan angin dan SWH rata-rata tahunan di WPP Indonesia, khususnya di WPP yang terletak di perairan Indonesia bagian dalam. Hasil penelitian ini dapat digunakan sebagai langkah awal dalam mitigasi dan adaptasi terhadap perubahan iklim. AbstractUnderstanding ocean waves is essential for maritime activities, especially for archipelagic countries such as Indonesia. In this study, the long-term trend of wind speed and Significant Wave Height (SWH) in the Indonesia’s Fisheries Management Areas (IFMAs) were analyzed during 1977–2021 (45 years) using data from the European Center for Medium-Range Weather Forecast (ECMWF) fifth generation reanalysis (ERA5). The results show an overall wind speed and SWH in the Indonesian seas have increased. The average trend of wind speed and SWH in all IFMAs were 0.29 cm/s/year and 0.19 cm/year. The long-term trend of wave height due to swell and wind sea in the IFMAs has also increased, with an average value of 0.18 and 0.05 cm/year. The highest increasing trend of wind speed and wave height were found in IFMAs facing the open ocean, such as IFMAs 717 (Northern Papua waters), 572 (Western Sumatran waters), and 573 (South Java waters). The El Niño-Southern Oscillation (ENSO) phenomenon, El Niño (La Niña) events affected the decrease (increase) in the annual average of the wind speed and SWH values in IFMAs, especially in IFMAs located in the inner seas. The results of this study could be used as an early assessment for mitigation and adaptation to climate change

Climate Variability in Indonesia from 615 ka to present: First Insights from Low-Resolution Coupled Model Simulations

We analyse the dynamics of Indonesian waters using the results of a set of 13 time-slice experiments simulated by the CCSM3-DGVM model. The experiments were carried out to study global climate variability between and within the Quaternary interglacials of Marine Isotope Stages (MIS) 1, 5, 11, 13, and 15. During boreal summer (June-July-August-September), in most of Indonesia, seasonal surface temperature anomalies can largely be explained by local insolation anomalies induced by the astronomical forcing. However, for some time slices, climate feedbacks may modify the surface temperature response in Indonesia, most pronounced in open water close to the Indian and Pacific Oceans. The warmest boreal summer sea-surface temperature (SST) anomaly compared to Pre-Industrial (PI) conditions of up to 1 K was found in the Banda Sea at 125 ka (MIS 5) and 579 ka (MIS 15). The coolest boreal summer SST anomaly down to –2 K at 495 ka (MIS 13) is equally distributed in Indonesian waters. During boreal winter, most of the moderate cooling over large portions of the land and the waters of Indonesia is also associated with local insolation. The most interesting finding in this study, a dipole and tripole precipitation pattern with up to 3.6 mm/day of rainfall anomaly during boreal summer is identified in the western part of the Indonesian waters, Indian Ocean to Banda Sea, and the eastern part of Indonesian waters. The results of this study are expected to be used as basic information to predict the climate in Indonesia for the present and future. This may add to the assessment provided by the IPCC for a better understanding of future climate change in the region, which is a prerequisite for alleviating its impacts

Pola Sirkulasi Arus Dan Salinitas Perairan Estuari Sungai Kapuas Kalimantan Barat

Telah dilakukan penelitian untuk mengkaji pola sirkulasi arus dan salinitas perairan estuari sungai Kapuas yang dibangkitkan oleh pasang surut, gaya pembangkit angin dan discharge sungai. Pada studi ini digunakan model numerik hidrodinamika MIKE 21 yang dikembangkan oleh DHI Water & Environment untuk mensimulasikan pola sirkulasi arus dan salinitas. Pola sirkulasi arus hasil simulasi menunjukkan pada kondisi pasang tertinggi, massa air bergerak dari utara ke selatan hingga masuk ke badan sungai sedangkan pada kondisi dan surut terendah massa air bergerak ke arah yang berlawanan (dari selatan ke utara) dan air mengalir dari sungai ke luar menuju lepas pantai. Pergerakan massa air pada kisaran kecepatan 0,05 sd 0,7 m/s. Pola sirkulasi arus baik saat purnama maupun perbani menunjukkan kesesuaian pola dan yang membedakan adalah besarnya kecepatan arus. Sebaran salinitas pada kondisi purnama (pasang tertinggi dan surut terendah) cenderung memiliki pola dan nilai yang sama dengan nilai salinitas dominan pada kisaran 33,2 s.d 33,4 PSU. Demikian pula pada kondisi perbani

The Movement of Plastic Marine Debris in Indonesian Seas using A Trajectory Model

There are many studies on ocean currents transporting plastic marine debris using hydrodynamic models and trajectories that have been carried out. However, it is still constrained to be applied in Indonesian waters. Therefore, this research aims to obtain the movement patterns of plastic marine debris, influenced by the dynamics of currents in Indonesian waters using hydrodynamic and trajectory models. The methodology used in this research is to use the HAMburg Shelf Ocean Model (HAMSOM) numerical model and the trajectory model. Plastic marine debris is assumed to be conservative particles at sea level with a macro size (2.5 cm-1 m). The particles are released in 6 coastal cities (Manado, Balikpapan, Makassar, DKI Jakarta, Semarang, and Denpasar) at the month and stop at the end month (January, April, July, October). The results showed that particles originating from 6 coastal cities moved along the current to the surrounding areas only, across islands within the Indonesian territory, and even left Indonesian territory

Kalimantan hydroclimate variability since the last glacial period

Changes in convective activity and hydroclimate over Northeastern Kalimantan are key features to understand glacial to interglacial climate evolution in the center of the West Pacific Warm Pool during the Late Pleistocene to Holocene. We use high-resolution X-ray fluorescence (XRF) scanner-derived elemental ratios in sediment Core SO217-18522 (1º 24.106’ N, 119º 4.701’E, 975 m water depth) recovered from the northern Makassar Strait to reconstruct changes in precipitation-related weathering and erosion over Northeastern Kalimantan over the last 50 kyr. Enhanced seasonality of rainfall and an extended dry season during Heinrich Stadials (HS4 to HS1) and the Younger Dryas (YD) suggest weakening of the tropical convection associated with a southward shift of the tropical rain belt and the annual mean position of the Intertropical Tropical Convection Zone. Increasing sediment discharge and intensification of convective activity occurred during the early to mid-Holocene during an interval of high Northern Hemisphere insolation, elevated atmospheric pCO2 levels and global warming. Our reconstructions in comparison with regional terrestrial and marine records highlight the high spatial variability of Kalimantan hydroclimate on millennial to glacial-interglacial timescales

沿岸海洋での海水循環・海底地形変動予測モデルに関する研究 : ジャワ海への適用

京都大学0048新制・課程博士博士(工学)甲第8314号工博第1879号新制||工||1164(附属図書館)UT51-2000-F218京都大学大学院工学研究科土木工学専攻(主査)教授 髙山 知司, 教授 酒井 哲郎, 助教授 間瀬 肇学位規則第4条第1項該当Doctor of EngineeringKyoto UniversityDA

Identifikasi Tinggi dan Jarak Genangan Daerah Rawan Bencana Rob di Wilayah Pantai Utara Jawa yang Disebabkan Gelombang Badai Pasang dan Variasi Antar Tahunan

AbstrakTinggi dan jarak genangan rob yang disebabkan oleh gelombang badaipasang (storm tide) dan variasi antar tahunan di sepanjang pantai utara Jawa disimulasikan dengan menggunakan model hidrodinamika 2D dengan fasilitas Flooding and Drying (FAD). Dalam simulasi tersebut, digunakan batimetri dari General Bathymetric Chart of the Oceans (GEBCO), peta DISHIDROS TNI-AL, dan topografi daerah utara Pulau Jawa berdasarkan data Digital Elevation Model (DEM) dari The NASA Shuttle Radar Topographic Mission (SRTM). Gaya penggerak gelombang badai pasang yang digunakan adalah data elevasi pasang surut yang diperoleh dari hasil prediksi Global Tidal Model ORI.96 dan data angin serta tekanan udara yang diperoleh dari National Centers for Environmental Prediction (NCEP). Naiknya elevasi yang disebabkan badai (surge) tertinggi di kawasan pesisir utara Jawa dan Madura terjadi di Tanjung Pangkah (Jawa: 18,6 cm) pada Januari 2008. Jarak genangan maksimum (Smax) gelombang badai pasang serta run-up yang menyertainya (H) terjadi di Sampang (Madura; Smax = 6552,3 m, H = 1,559 m) pada November 2007. Tinggi genangan tertinggi terjadi pada Januari 2008 yaitu pada saat La-Niña kuat. Hal ini menunjukkan bahwa kenaikan muka laut akibat La-Niña cukup berperan menambah kenaikan muka laut yang diakibatkan gelombang badai pasang.AbstractHeight and distance inundation caused by storm tide and interannual variations along the northern coast of Java have been simulated by using a 2D hydrodynamic model with Flooding and Drying facilities (FAD). In the simulation model, bathymetry data was derived from General Bathymetric Chart of the Oceans (GEBCO) and DISHIDROS Indonesian Navy maps, whereas topography of the northern area of Java was derived from Digital Elevation Model (DEM) of The NASA Shuttle Radar Topographic Mission (SRTM). Tidal elevation obtained from Global Tidal Model prediction ORI.96 and wind and air pressure data of National Centers for Environmental Prediction (NCEP) were used as generating force of storm tide. The highest surge in the northern coast of Java and Madura occurred in Pangkah Cape (Java; 18.6 cm) in January 2008. Maximum inundation distance (Smax) and run-up (H) existed in Sampang (Madura; Smax = 6552.3 m, H = 1,559 m) in November 2007. The highest inundation occurred in January 2008 during strong La-Niña period, this suggests that La-Niña have significant contribution to increase sea level rise caused by storm tide.

Study on Seasonal Variation of Cohesive Suspended Sediment Transport in Estuary of Mahakam Delta by using A Numerical Model

Abstract. A coupled three-dimensional hydrodynamics and sediment transport model of HydroQual, Inc., (2002), ECOMSED, has been used to simulate variation of suspended cohesive sediment transport in Estuary of Mahakam Delta. The simulation results indicate that tides and seasonal variation of river discharges are the main causes of variations in the suspended sediment concentration in this area. A one-year simulation of suspended sediment distribution shows that the suspended cohesive sediment discharge to the Makassar Strait is mainly transported southward, namely through locations of Muara Jawa and Muara Pegah and seems to reach a maximum distance of distribution in January and a minimum one in October. The simulation results also show that river discharges less influence the suspended sediment concentration at Tanjung Bayur, which is located at the tip of the channel in the middle, compared to the other locations. Abstrak. Suatu model kopel tiga dimensi hidrodinamika dan transpor sedimen HydroQual, Inc., (2002), ECOMSED, diterapkan untuk mensimulasi variasi transpor sedimen kohesif melayang di Estuari Delta Mahakam. Hasil simulasi menunjukkan bahwa pasut dan variasi musiman dari debit sungai adalah penyebab utama dari variasi konsentrasi sedimen melayang di daerah ini. Simulasi satu tahun distribusi sedimen melayang memperlihatkan bahwa sedimen kohesif yang memasuki Selat Makassar terutama ditransporkan ke arah selatan melalui Muara Jawa dan Muara Pegah. Jangkauan maksimum dari aliran sedimen memasuki Selat Makassar terjadi pada bulan Januari dan minimum pada bulan Oktober. Hasil simulasi juga menunjukkan bahwa pengaruh debit sungai terhadap konsentrasi sedimen di Tanjung Bayur lebih kecil daripada di lokasi-lokasi yang lain

Analysis of ocean wave characteristic in Western Indonesian Seas using wave spectrum model

Understanding the characteristics of the ocean wave in Indonesian Seas particularly in western Indonesian Seas is crucial to establish secured marine activities in addition to construct well-built marine infrastructures. Three-years-data (July 1996 - 1999) simulated from Simulating Waves Nearshore (SWAN) model were used to analyze the ocean wave characteristics and variabilities in eastern Indian Ocean, Java Sea, and South China Sea. The interannual or seasonal variability of the significant wave height is affected by the alteration of wind speed and direction. Interactions between Indian Ocean Dipole Mode (IODM), El Niño Southern Oscillation (ENSO) and monsoon result in interannual ocean wave variability in the study areas. Empirical Orthogonal Functions (EOF) analysis produces 6 modes represents 95% of total variance that influence the wave height variability in the entire model domain. Mode 1 was dominated by annual monsoon and has spatial dominant contribution in South China Sea effected by ENSO and Indian Ocean influenced by IODM. Java Sea was influenced by Mode 2 which is controlled by semi-annual monsoon and IODM. A positive (negative) IODM strengthens (weakens) the winds speed in Java Sea during the East (West) season and hence contributes to Mode 2 in increasing (decreasing) the significant wave in Java Sea