scholarly journals OKSIGEN TERLARUT DI SELAT LOMBOK

2014 ◽  
Vol 9 (1) ◽  
pp. 21
Author(s):  
Faisal Hamzah ◽  
Mukti Trenggono
Keyword(s):  
Equilibrium Concentration ◽  
Intermediate Water ◽  
Indonesian Throughflow ◽  
Oxygen Utilization ◽  
Northern Pacific ◽  
Apparent Oxygen Utilization

Oksigen merupakan gas penting dalam perairan laut dan berperan dalam proses biogeokimia laut. Sumber oksigen berasal dari difusi dari udara melalui proses turbelensi dan hasil fotosintesis. Penelitian ini bertujuan untuk mengkaji distribusi dan pengaruh Indonesian Throughflow (ITF) terhadap konsentrasi oksigen terlarut di Selat Lombok. Sebanyak 11 stasiun (3 di utara; 6 di tengah; 2 di selatan) dianalisis kandungan oksigen terlarutnya dengan menggunakan metode modifikasi winkler. Hasil analisis menunjukan bahwa kandungan oksigen di bagian utara berkisar 2,48-7,15 mg/l, tengah 2,32-6,58 mg/l dan selatan 2,35-6,71 mg/l. Berdasarkan nilai apparent oxygen utilization (-2,70–5,64 mg/l) dan normal atmospheric equilibrium concentration (3,84-7,96 mg/l), mencerminkan kandungan oksigen yang semakin berkurang pada lapisan permukaan. AOU dan NAEC secara implisit berubah terhadap kedalaman dimana konsentrasinya akan semakin tinggi  dengan bertambahnya kedalaman. Hasil pengukuran suhu dan salinitas menunjukan bahwa Selat Lombok mempunyai suhu dan salinitas masing-masing berkisar antara 4,74-30,080C dan 33,48-34,78 psu. Analisis TS-diagram menunjukan terdapat dua massa air yang membawa kandungan oksigen di Selat Lombok yaitu Northern Subtropical Lower Water (NSLW) (salinitas=34,53-34,58 psu, suhu=13,57-15,06 0C; sigma-t (s t)=25,40-25,80)) dan Northern Pacific Intermediate Water  (NPIW) (salinitas=34,48-34,54 psu; suhu=6,30-7,90 0C; sigma-t (s t)=26,70-27,20). NSLW ditemukan pada kedalaman 100-180 (utara), 100-550 m (tengah) dan 190-220 m (selatan), sedangkan NPIW tidak terlihat dengan menggunakan pendekatan oksigen terlarut dan hanya bisa dilihat dengan pendekatan suhu dan salinitas.

scholarly journals OKSIGEN TERLARUT DAN APPARENT OXYGEN UTILIZATION DI PERAIRAN WAIGEO BARAT, RAJA AMPAT

2019 ◽  
Vol 7 (2) ◽  
pp. 52-57
Author(s):  
Simon I Patty ◽  
Putri Sapira Ibrahim ◽  
Fione Yukita Yalindua
Keyword(s):  
Oxygen Utilization ◽  
Papua Barat ◽  
Apparent Oxygen Utilization

Pengamatan kadar oksigen terlarut telah dilaksanakan di perairan Waigeo Barat, Raja Ampat, Papua Barat. Penelitian ini bertujuan untuk mengetahui kondisi oksigen terlarut dan Apparent Oxygen Utilization (AOU).  Hasil analisa menunjukkan bahwa kadar oksigen terlarut di lapisan permukaan, 5 meter dan dekat dasar masing-masing berkisar antara 5.90-8.48 mg/l; 6.06-8.04 mg/l dan 6.12-7.98 mg/l. Berdasarkan nilai suhu dan salinitas yang diperoleh dari penelitian ini telah dihitung daya larut, derajat kejenuhan oksigen dan nilai AOU. Di lapisan permukaan nilai AOU berkisar antara (-0.01)-2.77 mg/l, di kedalaman 5 meter dan dekat dasar nilai AOU positif masing-masing berkisar antara 0.10-2.06 mg/l dan (0.16)-1.99 mg/l. Konsentrasi oksigen terlarut di perairan Waigeo Barat, Raja Ampat, belum menunjukkan dampak negatif terhadap lingkungan perairan dan masih sesuai dengan baku mutu air laut untuk biota laut. Kata kunci: Oksigen terlarut, AOU, Salinitas, Waigeo Barat, Raja Ampat

scholarly journals Seasonal variation of CaCO<sub>3</sub> saturation state in bottom water of a biological hotspot in the Chukchi Sea, Arctic Ocean

2016 ◽  
Vol 13 (22) ◽  
pp. 6155-6169 ◽  
Author(s):  
Michiyo Yamamoto-Kawai ◽  
Takahisa Mifune ◽  
Takashi Kikuchi ◽  
Shigeto Nishino
Keyword(s):  
Seasonal Variation ◽  
Bottom Water ◽  
Chukchi Sea ◽  
Early Summer ◽  
Biological Processes ◽  
Oxygen Utilization ◽  
Saturation State ◽  
High Productivity ◽  
Major Factors ◽  
Apparent Oxygen Utilization

Abstract. Distribution of calcium carbonate saturation state (Ω) was observed in the Chukchi Sea in autumn 2012 and early summer 2013. Ω in bottom water ranged from 0.3 to 2.0 for aragonite and from 0.5 to 3.2 for calcite in 2012. In 2013, Ω in bottom water was 1.1–2.8 for aragonite and 1.7–4.4 for calcite. Aragonite and calcite undersaturation was found in high productivity regions in autumn 2012 but not in early summer 2013. Comparison with other parameters has indicated that biological processes – respiration and photosynthesis – are major factors controlling the regional and temporal variability of Ω. From these ship-based observations, we have obtained empirical equations to reconstruct Ω from temperature, salinity and apparent oxygen utilization. Using 2-year-round mooring data and these equations, we have reconstructed seasonal variation of Ω in bottom water in Hope Valley, a biological hotspot in the southern Chukchi Sea. Estimated Ω was high in spring and early summer, decreased in later summer, and remained relatively low in winter. Calculations indicated a possibility that bottom water could have been undersaturated for aragonite on an intermittent basis even in the pre-industrial period, and that anthropogenic CO2 has extended the period of aragonite undersaturation to more than 2-fold longer by now.

scholarly journals Indirect estimation of turbulent mixing in western route of Indonesian throughflow

2021 ◽  
Vol 944 (1) ◽  
pp. 012059
Author(s):  
M Firdaus ◽  
H Rahmawitri ◽  
S Haryoadji ◽  
A S Atmadipoera ◽  
Y Suteja ◽  
...  
Keyword(s):  
Turbulent Mixing ◽  
Intermediate Water ◽  
Indonesian Throughflow ◽  
Pacific Water ◽  
Dissipation Energy ◽  
Tidal Waves ◽  
Water Characteristics ◽  
Vertical Diffusivity ◽  
Water Origin ◽  
Waves Interaction

Abstract The Indonesian Throughflow (ITF) via its western path conveys mainly North Pacific water origin with Smax thermocline water and Smin intermediate water from its entry portal in Sangihe-Talaud arcs to the main outflow straits in Lombok, Ombai and Timor passage. Along its route, the throughflow water characteristics transforms significantly due to strong diapycnal mixing forced by internal tidal waves interaction along complex topography such as passages, sill, straits, and shallow islands chains. This paper reports a brief estimate of turbulent mixing profiles in Sangihe chains, and Makassar Strait. The CTD dataset are obtained from the year of maritime continent (YMC) Cruise in August 2019 on board the R.V. Baruna Jaya I. The Thorpe method is used to analysis dissipation energy ( ε ) and vertical diffusivity (Kz ) from CTD dataset. It is shown that the highest ε epsilon 5.87 × 10−7 Wkg −1 and Kz 4.42 × 10−3 m2s 1 are found in the Sangihe area. In Labani Channel and Dewakang Sill the averaged vertical diffusivity is much weaker at the order of 10−4 m 2s1. Thus, Sangihe Chains station have the highest values compared to other stations at depth 950-1000 meters.

scholarly journals Dissolved Oxygen and Apparent Oxygen Utilization in Lembeh Strait Waters, North Sulawesi

2017 ◽  
Vol 6 (1) ◽  
pp. 54
Author(s):  
Simon I Patty
Keyword(s):  
Surface Layer ◽  
Dissolved Oxygen ◽  
Sea Water ◽  
Negative Impact ◽  
Quality Standards ◽  
Water Quality Standards ◽  
Oxygen Utilization ◽  
North Sulawesi ◽  
Lembeh Strait ◽  
Apparent Oxygen Utilization

The observation of dissolved oxygen level and Apparent Oxygen Utilization (AOU) in Lembeh Strait Waters was conducted in January, February, June and July 2016. The objective of this research is to know the condition of dissolved oxygen and Apparent Oxygen Utilization (AOU). The results of the analysis showed that dissolved oxygen levels in the surface layer and near the bottom ranged from 6.00-6.56 mg/l and 5.59-6.17 mg/l. Based on the values of temperature and salinity obtained from this study, solubility, oxygen saturation degree and AOU value at the surface layer were calculated. In the surface layer the AOU values are positive, ranging from 0.10-0.72 mg/l, while near the bottom, negative and positive AOU values were balanced, ranging from -0.23-0.42 mg/l. The concentration of dissolved oxygen in the Lembeh Strait waters has not shown negative impact on the aquatic environment and is still in accordance with sea water quality standards for marine biota.Keywords: Dissolved oxygen, apparent oxygen utilization (AOU), Lembeh Strait. ABSTRAK         Pengamatan kadar oksigen terlarut dan Apparent Oxygen Utilization (AOU) di Perairan Selat Lembeh dilaksanakan pada bulan Januari, Februari, Juni dan Juli 2016. Penelitian ini bertujuan untuk mengetahui kondisi oksigen terlarut dan Apparent Oxygen Utilization (AOU). Hasil analisa menunjukkan bahwa kadar oksigen terlarut di lapisan permukaan dan dekat dasar berkisar antara 6,00-6,56 mg/l dan 5,59-6,17 mg/l. Berdasarkan nilai suhu dan salinitas yang diperoleh dari penelitian ini telah dihitung daya larut, derajat kejenuhan oksigen dan nilai AOU pada lapisan permukaan. Di lapisan permukaan nilai AOU semuanya positip berkisar antara 0,10-0,72 mg/l dan di dekat dasar nilai AOU negatip dan positip berimbang, berkisar antara       -0,23-0,42 mg/l. Konsentrasi oksigen terlarut di perairan Selat Lembeh belum menunjukkan dampak negatip terhadap lingkungan perairan dan masih sesuai dengan baku mutu air laut untuk biota laut. Kata Kunci: Oksigen terlarut, apparent oxygen utilization (AOU), Selat Lembeh.

scholarly journals Sedimentary supply of humic-like fluorescent dissolved organic matter and its implication for chemoautotrophic microbial activity in the Izu-Ogasawara Trench

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Shigemitsu ◽  
T. Yokokawa ◽  
H. Uchida ◽  
S. Kawagucci ◽  
A. Murata
Keyword(s):  
Organic Matter ◽  
Community Structure ◽  
Dissolved Organic Matter ◽  
Oxygen Utilization ◽  
Fluorescent Dissolved Organic Matter ◽  
Vertical Distributions ◽  
The Difference ◽  
The Relationship ◽  
Apparent Oxygen Utilization

AbstractMicrobial community structure in the hadal water is reported to be different from that in the upper abyssal water. However, the mechanism governing the difference has not been fully understood. In this study, we investigate the vertical distributions of humic-like fluorescent dissolved organic matter (FDOMH), chemoautotrophic production, apparent oxygen utilization (AOU), and N* in the Izu-Ogasawara Trench. In the upper abyssal waters (< 6000 m), FDOMH has a significantly positive correlation with AOU; FDOMH deviates from the relationship and increases with depth without involving the increment of AOU in the hadal waters. This suggests that FDOMH is transferred from the sediments to the hadal waters through pore water, while the FDOMH is produced in situ in the upper abyssal waters. Chemoautotrophic production and N* increases and decreases with depth in the hadal waters, respectively. This corroborates the effluxes of dissolved substances, including dissolved organic matter and electron donors from sediments, which fuels the heterotrophic/chemoautotrophic microbial communities in the hadal waters. A simple box model analysis reveals that the funnel-like trench topography facilitates the increase in dissolved substances with depth in the hadal waters, which might contribute to the unique microbiological community structure in these waters.

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