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The Effect of ENSO on the Upwelling Intensity in the Seas along the Northern Coast of Papua: A Case Study of the 2015-2016 El Niño and the 2010-2011 La Niña Events

Lesmana Petrik Siano Okta Prima, Wirasatriya Anindya, Setiyono Heryoso, Suryoputro Agus Anugroho Dwi, Wijaya Yusuf Jati, Ismunarti Dwi Haryo, Haryanti Dwi, Abdillah Muhammad Rais

Ecological Engineering & Environmental Technology

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2024

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Vol. 25, iss. 2

243--253

EN

The seas along the Northern Coast of Papua constitute a region with complex oceanographic conditions as they are situated within the Indo-Pacific warm pool (IPWP). The geographical location in the southern hemisphere induces upwelling during the west monsoon season (December-January-February). Additionally, interannual phenomena such as the El Niño Southern Oscillation (ENSO) can impact the intensity of upwelling in these waters. This study aimed to compare the upwelling intensity in the seas along the Northern Coast of Papua during neutral phases and ENSO phases. The main indicators of upwelling are sea surface temperature (SST) and Ekman mass transport (EMT). The data utilized in this study include SST from GHRSST and surface wind from ASCAT. The data processing employed the monthly composite method with spatiotemporal analysis based on anomaly results derived from monthly climatology. The analysis results reveal that El Niño 2015–2016 led to an increase in upwelling intensity ranging from 1.82 to 4.00 m/s2, while La Niña 2010–2011 resulted in a weakening of upwelling intensity ranging from 4.95 to 6.56 m/s2 in the seas along the Northern Coast of Papua. On the basis of correlation and regression analysis, it can be concluded that offshore EMT significantly influences upwelling anomalies in the southeastern waters, whereas the northwestern waters are more influenced by the shifting IPWP during ENSO.

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Carbon dioxide flux and its relationship to water quality in the Teluk Awur - Jepara, Indonesia

Petrova Cendra Boskanita, Maslukah Lilik, Indrayanti Elis, Wijaya Yusuf Jati, Prayitno Hanif Budi, Afdal Afdal, Wirasatriya Anindya

Ecological Chemistry and Engineering. S

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2024

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Vol. 31, nr 3

315--328

EN

Anthropogenic activities on land will affect the carbon system in coastal waters. This condition will affect the role of coastal waters as a source or sink of carbon. This research will examine the distribution of carbonate systems and estimate CO2 fluxes. Water samples were taken at 30 stations as well as measuring in situ water parameters including pH, temperature, salinity, and pressure. Alkalinity was analysed based on the titration method, chl-a using the fluorometer method, and carbonate system parameters (pCO2(sea) and DIC) calculated using CO2SYS.xlsm. The pCO2(atm) value is calculated based on atmospheric data from satellite data, including the saturation vapour pressure of sea air in the atmosphere, fraction mol of CO2, and sea level pressure. Pearson correlation analysis was used to see the correlation between the measured parameters and CO2 flux. Carbon flux is determined based on the difference between atmospheric and oceanic pCO2. The DIC calculation result was in the range of 1,946.09 μmol/kg - 2,061.65 μmol/kg and the total alkalinity was 2,156.86 μmol/kg - 2,264.71 μmol/kg. Based on this value, Jepara coastal waters have pCO2(sea) of 573,800 micro-atmospheric (μatm) which is higher than pCO2(atm) (i.e., 386,772 μatm). The input of organic/inorganic carbon resulting from anthropogenic processes on land has influenced Jepara coastal waters which act as a source of CO2 into the atmosphere amounting to 103,799 mmol/m2/day. The results of this research can be used as a reference for managing coastal areas to achieve low carbon emissions.

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The Temporal Trends in Chlorophyll-A Concentration along the Southern Coast of Papua over a 25-year Period, from 1998 to 2022

Wijaya Yusuf Jati, Munandar Bayu, Wisha Ulung Jantama, Hidayat Esa Fajar, Rejeki Hasti Amrih, Ismunarti Dwi Haryo

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 6

82--93

EN

The region situated along the southern coast of Papua Island exhibits a considerable likelihood of upwelling, which is distinguished by higher amounts of chlorophyll-a concentration. The present study examined the variability of upwelling phenomena spanning a period of 25 years (1998-2022) through the utilization of satellite-derived data obtained from the Ocean-Colour Climate Change Initiative (OC-CCI). Apart from the chlorophyll-a concentration, the southern region of Papua exhibits a significant amount of suspended sediment contamination, as indicated by the observations of Rrs 555. Upon conducting EOF analysis during each season, it has been observed that there has been a significant rise in the levels of chlorophyll-a concentrations over the past several years in the northern region of the Arafura Sea. The period spanning from 2016 to 2022 witnessed a rise in precipitation amounts, leading to a greater transportation of nutrients through water discharge and consequently resulting in an increase of chlorophyll-a concentration.

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Estimation of Land Subsidence Using Sentinel Image Analysis and Its Relation to Subsurface Lithology Based on Resistivity Data in the Coastal Area of Semarang City, Indonesia

Widada Sugeng, Zainuri Muhammad, Yulianto Gatot, Satriadi Alfi, Wijaya Yusuf Jati

Journal of Ecological Engineering

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2020

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Vol. 21, nr 8

47--56

EN

The Semarang city is the capital of the Central Java Province that is experiencing rapid urban growth. Land subsidence in Semarang has been widely reported and its impacts can be seen already in daily life. In order to minimize its damage, land subsidence monitoring is required as a part of natural disaster mitigation. On the other hand, understanding of the subsurface lithology conditions is needed to explore the causes of subsidence in certain areas. One of the methods of monitoring land subsidence is by utilizing Synthetic Aperture Radar (SAR) satellite image which is used in this research. In turn, the subsurface lithology can be studied with the geoelectric methods, one of which is the resistivity method. The purpose of this research is to estimate the land subsidence in the Semarang city using the Sentinel Image Analysis by means of the DInSAR Method and its relation with subsurface lithology studied using the resistivity geoelectric method. The result of the research shows that the average value of subsidence was located in the Genuk District area and Semarang Utara District area which each subsidence value is 9.8 cm/year and 12.7 cm/year. This is because the lithology under the surface of the two locations is clay and silt in a soft condition that is thicker than other locations. The saltwater content contributes to the consolidation process in the lithology. There is a tendency that land subsidence is greater in the port and industrial areas than in other regions, due to building loads.