Diverse impact of 2023 El Niño on weather patterns over the Indonesian Maritime Continent Sanaullah Zehri, Erma Yulihastin, Fiolenta Marpaung, Agung Adiputra, Mushoddik, et al. Journal of Southern Hemisphere Earth Systems Science, 2025 The El Niño–Southern Oscillation (ENSO) significantly affects climate extremes, particularly causing the driest conditions across the Indonesian Maritime Continent (IMC). However, the specific impacts of the 2023 ENSO on weather pattern anomalies in the IMC have not been thoroughly explored. This study examines the 2023 El Niño, one of the strongest El Niño conditions during the warmest climate decade, and its effects on weather anomalies (i.e. hot and humid) to fill gaps in our understanding of the diverse impacts of ENSO in the IMC. Composite analysis (1991–2023) from the European Centre for Medium-Range Weather Forecasts Reanalysis v5 (ERA5) and National Oceanic and Atmospheric Administration datasets demonstrated that the 2023 El Niño strengthened westerly winds across the Pacific Ocean and influenced intraseasonal rainfall patterns over the IMC. Distinct contrasts were observed between northern (DOM1) and southern (DOM2) IMC. During the onset and mature periods of El Niño (April–September 2023), DOM2 experienced reduced rainfall and significant drought, especially during the dry season (June–September 2023), affecting vital agricultural regions in Java and southern Sumatra. The positive Indian Ocean Dipole and vigorous Australian monsoon likely intensified this drought. Conversely, DOM1 experienced increased rainfall, triggering severe flood events in several regions in Sumatra and Kalimantan (i.e. northern Sumatra and western, northern and central Kalimantan). Our findings highlighted that the enhanced rainfall, driven by middle and high cloud activities, is linked to ENSO and South China Sea warming. This study deepens our understanding of the varied impacts of El Niño on intraseasonal weather patterns in Indonesia, ultimately aiding in improving sub-seasonal-to-seasonal climate predictions over the IMC.
Nonstationary Changes in Annual Rainfall over Indonesia's Maritime Continent Gian Gardian Sudarman, Tri Wahyu Hadi, Nining Sari Ningsih, Ardhasena Sopaheluwakan, Muhammad Ridho Syahputra, et al. Advances in Meteorology, 2024 The investigation into changing rainfall patterns in the Indonesian Maritime Continent (IMC) involved testing for trends, step changes, and variance nonstationarity using the Mann–Kendall, Pettitt, and White tests, respectively. The analysis covered data from 106 meteorological stations over the period from 1981 to 2021, with all tests conducted at annual time scales to understand the evolving precipitation dynamics in the region. According to the findings of this study, the average annual rainfall in IMC is nonstationary. Rainfall has increased dramatically by 12.72 mm with a significant shift point in 1994. However, this characteristic is likely to vary if the analysis period is extended, reduced, or conducted in different time frames. The spatial analysis indicates that 35.8% of meteorological stations observed a notable increase in rainfall, while 28.3% experienced a significant shift, and 16% displayed considerable variation. Consequently, the study only partially identified the nonstationary nature of rainfall in the IMC. Moreover, the research highlights a substantial rise in rainfall in the central to eastern IMC region, whereas the central to western region predominantly shows a decrease. This nonstationary test helps avoid errors in climatic conditions and analytical methods, presenting recommendations for hydrological projects. Consequently, employing this nonstationary test helps prevent inaccuracies in understanding climatic conditions and analytical techniques, thereby offering valuable suggestions for hydrological projects.
Multi-Criteria Decision Analysis (MCDA) for estimate economic valuation for flood risk in DKI Jakarta Province F Marpaung, D Fernando, N Setyaningrum, S Lestari, R Sulistyowati, et al. Iop Conference Series Earth and Environmental Science, 2023 A 4-day-flood occurred in Jakarta Province, Indonesia at the end of 2019 caused severe moral and material losses and weakened the economy. Various flood risk management methods are available to mitigate this damage. Assessing flood risks is thus an essential task for disaster management activities. An accurate flood risk map is required to be developed. In this research, we developed an economic valuation of flood risk that combines a quick flood map with the consequences of flooding using the Multi – Criteria Decision Analysis (MCDA) in the DKI Jakarta area. A quick identification of flood zones was carried out using SAR (Synthetic Aperture Radar). We estimated that about 54.10 km2 area was flooded area with a total economic loss about 1.406 trillion rupiahs. The sector of construction (10.10%), manufacturing (11.51%), wholesale, rental trade and repair of vehicles (13,90%), business activities (6.77%), financial & insurance (7.33%), and information & communication (7.6%) are major affected sectors that contributes 56.86% of the total economic loss from the market value. 20.49%-other service activities implicitly underestimate the value of environmental services and human productivities. To understand this, a detailed analysis of non-market value is needed in understanding the actual total economic loss.
Interaction of Air and Sea above Seamount in the Halmahera Sea D P Sobaruddin, F. Marpaung, R.A.B. Putra, A. Fahim, C.S. Dharma, et al. Iop Conference Series Earth and Environmental Science, 2022 The interaction of sea and air plays a very important role in the early stages of cloud formation. In certain cases, changes in temperature in the sea surface layer and the atmospheric layer closest to the sea will affect the initiation of the formation of water vapor which can become cloud. To monitor the sea-air temperature interaction above Seamount in Halmahera Sea, we took an expedition of Jala Citra-I 2021 Aurora from August 28 to September 9, 2021 using The Indonesian Navy Center for Hydrography and Oceanography research vessel, the Navy’s KRI Spica-934. Weather condition was observed using two installed Automatic Weather Stations (AWS) mounted on a vessel, radiosonde in Sorong, West Papua, and Outgoing Longwave Radiation (OLR) data from NOAA (National Oceanic and Atmospheric Administration), while the profile of sea surface temperature (SST) were observed using a 24-hour CTD measurement. Both AWS data were analyzed using two samples Kolmogorov-Smirnov test with h=1 and showed low correlations (r2 = 0.2-0.4, p-value <0.01) for the parameters of temperature, relative humidity, and wind speed. The hourly SST ranged 29°C – 30°C from 0-50 meter and the Lifting Condensation Level ranged about 939 to 985 mb in the morning on 1 - 2 September. The OLR was a neutral and positive values. These conditions indicated that a strong local effect dominantly created by a strong sea-air interaction in the study area. A warm SST with a strong divergence wind leads a warm air layer developed on the sea surface to rise. A low OLR with a moderate CAPE is enough to support the updraft of water vapor, rising from sea surface and then support convective activity formed in the region. In addition, it shows that the changes activity of convective clouds, developing over warm waters, are dominant mode of diurnal variability. However, investigation of intra-seasonal variability in Halmahera Sea was not clear. Further investigation on spatiotemporal of sea-air interaction on a local scale are needed to capture the phenomena on its season.
Sentinel 1 SAR for Rapid Identification of Flooded Inquiries in South Kalimantan Province Nugraheni Setyaningrum, Dynosius Bryan Sencaki, Fiolenta Marpaung, Muhamad Dayuf, Aji Putra Perdana Proceedings 2021 7th Asia Pacific Conference on Synthetic Aperture Radar Apsar 2021, 2021 An 2021-flood occurred in South Kalimantan Province caused severe moral and material losses, the destruction of nature, and weakened the wheel of the economy. Rapid identification of affected flood inundation areas spatially is essential for monitoring and assisting in the preparation of emergency responses. Spatial analysis of flood areas utilizes SAR (Synthetic Aperture Radar) images because its wavelength is able to penetrate well through clouds or hazy atmosphere. This study utilizes Sentinel-1A level GRD (Ground Range Detect) - IW (Interferometric Wide Swath Mode) images with VV and VH polarization. We used Remote Sensing Change Detection (RDCD) method and then implemented a flood threshold. Flood event verification is obtained from the crowdsourcing report of flood events through social media. Results shows that 11 districts of South Kalimantan were affected by flooding, namely Balangan Regency (3,498 ha), Banjar (47,548 ha), Barito Kuala (37,530 ha), Hulu Sungai Selatan (9,939 ha), Hulu Sungai Tengah (9,789 ha), Hulu Sungai Utara (13,002.24 ha), Tabalong (4,876 ha), Tanah Laut (25,931 ha), Tapin (15,597 ha), Banjarbaru (2,812 ha) and Banjarmasin (6,570 ha).
Environmental Influence on a Rabies Spread Modelling in North Sulawesi, Indonesia Fiolenta Marpaung, Dionysius Bryan Sencaki, Siti Arfah, Agustan Agustan, Oni Bibin Bintoro, et al. Proceeding Agers 2020 IEEE Asia Pacific Conference on Geoscience Electronics and Remote Sensing Technology Understanding the Interaction of Land Ocean and Atmosphere Disaster Mitigation and Regional Resillience, 2020 Numerous studies about the transmission of rabies have been reported to not restrict by administrative boundaries and the history of occurrence of the diseases. These conditions were influenced by surrounding environments, economic conditions, and human and animal habits. The environmental factors such as land use, water bodies, forests, and land slopes are considered to be the defining factor for migrating rabid animals to move from place to place. The study of the spread of rabies cases based on environmental elements that can predict the direction of the spread of rabies cases overtime is needed. Yet, information on how environmental conditions affect the dispersal pattern of human rabies or rabid remains unclear. Hence, we analyzed it and they considered it to be the input of the rabies alert system. Environmental factors on human rabies and rabid dogs are explored to define the spatial rating distribution of rabies in North Sulawesi Province, Indonesia. The purpose of this work is to obtain up a spatial model design to help predict rabies spread patterns based on land closure conditions. The result shows that a combination using the land cover, slope/ elevations and location of the cases significantly shows the dispersal pattern of rabid animals. It is dominantly happening in urban areas with a low slope condition and represents about 80% of the total human rabies cases. Still, this study was limited to the movement of rabid animals due to a lack of rabid-animals and animal populations. Thus, future analysis of epidemiology rabies predictions is needed.
Profile of dielectric constant of peat in Ogan Komering Ilir Regency, Indonesia using SAR Sentinel-1 and ground penetrating radar F Marpaung, Sumirah, L Sumargana, D Nugroho Iop Conference Series Earth and Environmental Science, 2020 Profile of dielectric constant of a substance or a surface indicates its electromagnetic parameters. The profile is associated with electric polarization, permeability with magnetic polarization, and conductivity with an electric current field. In the practice, the Synthetic Aperture Radar (SAR) and the Ground Penetrating Radar (GPR) are commonly utilized to determine how much velocity of a substance and its scattering profiles. However, information about the profile radar scattering mechanisms in tropical peatland is still limited. Therefore, we evaluated dielectric constant from the field using GPR and estimated its spatial variation from a dual-polarization Sentinel-1A type C-band SAR in Ogan Komering Ilir, South Sumatera Province, Indonesia. We measured dielectric constant at the two major types of land use, namely oil palm and acacia. Results indicated that the dielectric constant derived from SAR Sentinel-1A and GPR are affected by peat moisture. It increases as the peat moisture increases. Results show that during peat dry conditions, the profiles of dielectric constant derived from dual-pol Sentinel-1A images are relatively similar to the dielectric constant of peat in Siak Regency. It ranges between 31.78 and 59.3. The dielectric constant derived from GPR ranges between 69 and 70.
Early study of magnetic permeability and magnetic susceptibility of peat in Ogan Komering Ilir, South Sumatera, Indonesia Anisah, F Marpaung, A Purwandani, D Nugroho, L Sumargana Iop Conference Series Earth and Environmental Science, 2020 Increasing peat fire in Indonesia have encouraged government or research institutes to develop an early warning system. This system needs various parameters in order to have an accurate result. Magnetic permeability and susceptibility are the physical properties of peat which expected to support this system. Field and laboratory measurements were conducted to determine the relationship between the peat temperature rise and the physical properties of the peat. A total of 30 samples was collected from Ogan Komering Ilir (OKI) Regency, South Sumatera, Indonesia. Each sample was tested with a temperature rise of 20°C until reach the convergent temperature. Statistical analysis were then performed. The results show that the magnetic permeability correlate with the peat temperature but the coefficient of the linear regression model is very small, with the constanta of 1.0022 from the linear regression model. In addition, magnetic susceptibility have a small correlation and a small determination coefficient with temperature. Therefore, it indicates that magnetic susceptibility can't support this system.
Tropical Peat Moisture Profiles for Early Information of Drought in Indonesia Fiolenta Marpaung, Doni Fernando, Sepanie Putiamini Proceedings 2018 IEEE Asia Pacific Conference on Geoscience Electronics and Remote Sensing Technology Best Practice for Disaster Mitigation Using Geoscience Electronic and Remote Sensing Agers 2018, 2018
