scholarly journals PHENOMENA INTRUSI DASAR DI TELUK HURUN LAMPUNG

2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Arif Dwi Santoso
Keyword(s):  
Water Temperature ◽  
Vertical Profile ◽  
Water Mass ◽  
Bottom Layer ◽  
Monitoring Data ◽  
Océanographic Survey ◽  
Profile Distribution ◽  
Java Sea

Research aimed to learn and know the bottom intrusion mechanism in Hurun Bay Lampung. Three kinds surveys were conducted consist of mooring survey, synoptic oceanographic survey and 25 hour survey. The monitoring data of water temperature indicated that at Hurun Bay occurred bottom intrusion from middle February until early July. The mass water was colder, more saline and contained less DO than the overlaying water. These phenomena may be caused by eastern monsoon from Java Sea to Lampung Bay and Hurun Bay. Vertical profile distribution showed that there are significant different in temperature, salinity and DO between surface and bottom layer. Along bottom deeper than 22m were identified as a termocline layer which was colder and more saline and contained less DO. Result of 25 hour survey resumed that the lowest DO in this water mass appeared in early July and it propagated from offshore to the coast with velocity 0.07 m/s. This condition will be a treatment for marine cultivation stakeholder in this area.Key words : Bottom Intrusion, Hypoxia

scholarly journals Distribution of Arctic and Pacific copepods and their habitat in the northern Bering Sea and Chukchi Sea

2015 ◽  
Vol 12 (22) ◽  
pp. 18661-18691 ◽  
Author(s):  
H. Sasaki ◽  
K. Matsuno ◽  
A. Fujiwara ◽  
M. Onuka ◽  
A. Yamaguchi ◽  
...  
Keyword(s):  
Sea Ice ◽  
Water Mass ◽  
High Salinity ◽  
Chukchi Sea ◽  
Bottom Layer ◽  
Sea Ice Extent ◽  
High Salinity Water ◽  
Explanatory Variables ◽  
Northern Bering Sea ◽  
Salinity Water

Abstract. The advection of warm Pacific water and the reduction of sea-ice extent in the western Arctic Ocean may influence the abundance and distribution of copepods, i.e., a key component in food webs. To understand the factors affecting abundance of copepods in the northern Bering Sea and Chukchi Sea, we constructed habitat models explaining the spatial patterns of the large and small Arctic copepods and the Pacific copepods, separately, using generalized additive models. Copepods were sampled by NORPAC net. Vertical profiles of density, temperature and salinity in the seawater were measured using CTD, and concentration of chlorophyll a in seawater was measured with a fluorometer. The timing of sea-ice retreat was determined using the satellite image. To quantify the structure of water masses, the magnitude of pycnocline and averaged density, temperature and salinity in upper and bottom layers were scored along three axes using principal component analysis (PCA). The structures of water masses indexed by the scores of PCAs were selected as explanatory variables in the best models. Large Arctic copepods were abundant in the water mass with high salinity water in bottom layer or with cold/low salinity water in upper layer and cold/high salinity water in bottom layer, and small Arctic copepods were abundant in the water mass with warm/saline water in upper layer and cold/high salinity water in bottom layers, while Pacific copepods were abundant in the water mass with warm/saline in upper layer and cold/high salinity water in bottom layer. All copepod groups were abundant in areas with deeper depth. Although chlorophyll a in upper and bottom layers were selected as explanatory variables in the best models, apparent trends were not observed. All copepod groups were abundant where the sea-ice retreated at earlier timing. Our study might indicate potential positive effects of the reduction of sea-ice extent on the distribution of all groups of copepods in the Arctic Ocean.

Implementation and Validating of the Regional Ocean Model System (ROMS) for the Sunda Strait connecting the Java Sea to the Indian Ocean

2021 ◽  
Author(s):  
Subekti Mujiasih ◽  
Jean-Marie Beckers ◽  
Alexander Barth
Keyword(s):  
Time Series ◽  
Indian Ocean ◽  
Vertical Profile ◽  
Ocean Model ◽  
Model System ◽  
Satellite Sst ◽  
Regional Ocean Model System ◽  
Regional Ocean Model ◽  
The Indian Ocean ◽  
Java Sea

<p>Regional Ocean Model System (ROMS) has been simulated for the Sunda Strait, the Java Sea, and the Indian Ocean. The simulation was undertaken for thirteen months of data period (August 2013 – August 2014). However, we only used four months period for validation, namely September – December 2013. The input data involved the HYbrid Coordinate Ocean Model (HYCOM) ocean model output by considering atmospheric forcing from the European Centre for Medium-Range Weather Forecasts (ECMWF), without and with tides forcing from TPXO and rivers. The output included vertical profile temperature and salinity, sea surface temperature (SST), seas surface height (SSH), zonal (u), and meridional (v) velocity. We compared the model SST to satellite SST in time series, SSH to tides gauges data in time series, the model u and v component velocity to High Frequency (HF) radial velocity. The vertical profile temperature and salinity were compared to Argo float data and XBT. Besides, we validated the amplitude and phase of the ROMS seas surface height to amplitude and phase of the tides-gauges, including four constituents (M2, S2, K1, O1).</p>

Stereo Monitoring and Analysis on Wind Energy Source in Chongqing

2011 ◽  
Vol 347-353 ◽  
pp. 742-749 ◽  
Author(s):  
Yan Ying Chen ◽  
Yang Sheng You ◽  
Yang Hua Gao ◽  
Qin Du ◽  
Yun Hui Tang
Keyword(s):  
Energy Source ◽  
Wind Speed ◽  
Wind Energy ◽  
Vertical Profile ◽  
Monitoring Data ◽  
Wind Data ◽  
Power Exponent ◽  
Technology Level ◽  
Wind Resource

In this paper, sequential 12 months’ wind data was used which is obtained from professional observing towers and meteorological stations in Chongqing. Wind energy source was calculated and analyzed. The results of calculation and analysis based on stereo monitoring data to wind resource in Chongqing showed as following: (1) Data of meteorological stations can be used to accurately evaluate wind energy source in Chongqing; (2) There are developable wind energy source at present technology level in Chongqing; (3) Vertical profile of wind speed fitted power exponent relationship.

scholarly journals BEHAVIOR OF ANOXIC WATER IN THE BANGPAKONG ESTUARY

2015 ◽  
Vol 37 (2) ◽  
pp. 109-121 ◽  
Author(s):  
Akihiko Morimoto
Keyword(s):  
Water Mass ◽  
Bottom Layer ◽  
Anoxic Condition ◽  
Mass Mortality ◽  
Series Data ◽  
Current Direction ◽  
Tidal Variation ◽  
Residual Currents ◽  
Anoxic Water ◽  
Aquaculture Area

We carried out hydrographic observations in the Bangpakong estuary during transient period from rainy season to dry season in 2011 and 2012. The main objective of the hydrographic observations was to elucidate the behavior of anoxic water mass in the Bangpakong estuary, which was the possible cause of mass mortality of cultured shellfishes in the study area. We had succeeded the CTD and mooring observations in both years, and we had obtained time–series data of DO, salinity, and current velocity for approximately 2 months, which were the first long-term continuous records in terms of water quality in the Bangpakong estuary. From mooring data, it was revealed that DO and salinity at the bottom layer in aquaculture area oscillated with large amplitude, and the period of the oscillation corresponded to tidal variation. Amplitude of the oscillation was large in September and became small in October, and anoxic condition lasted for several days in October in 2011 and 2012. Current direction at station M1 in 2011 was opposite to that of in 2012 throughout the mooring period southward in 2011 and northward in 2012. Wind conditions in Chonburi in both years were almost the same, but river discharge in 2011 was much higer than that of in 2012. Therefore, it was possible that the difference of current direction at station M1 occurred due to change of buoyancy flux, and persistent period of anoxic condition was different between 2 observed years associated with circulation change. It was suggested that mass mortality of cultured shellfishes in Bangpakong estuary was caused by anoxic water because timing of mass mortality corresponded to that of anoxic water appearance qualitatively. It was also suggested that the anoxic water mass in aquaculture area was transported from off shore area by residual currents.

Longitudinal distribution and vertical profile of pH, temperature and dissolved oxygen in a partially aerated facultative pond

2000 ◽  
Vol 42 (10-11) ◽  
pp. 75-81
Author(s):  
H. N. Melo ◽  
P. Guimarães ◽  
J. L. Melo
Keyword(s):  
Dissolved Oxygen ◽  
Vertical Profile ◽  
Thermal Stratification ◽  
Soft Drink ◽  
Isothermal Condition ◽  
Bottom Layer ◽  
Longitudinal Distribution ◽  
Good Efficiency ◽  
Photosynthetic Activities ◽  
Constant Gradient

The system consists of a partially aerated facultative pond with a polished area that treats the effluents of a soft drink industry in Brazil. This work concerns on the study of the longitudinal distribution as well as the analysis of the vertical profile of the main control parameters which exerts a direct influence on the metabolism of the system. The results show the existence of a horizontal thermal gradient between aerated and polishing zones, which is more intense at the surface of the first 40 metres. The vertical profile did not identify a tendency to thermal stratification. The constant gradient vertical of 0.1°C in the aerated and polishing zones characterizes an almost isothermal condition. The decrease of the effluent pH values was observed in the bottom layer of the pond. This indicates that the anaerobic digestion on the sedimented sludge incorporates acids in the liquid mass. The dissolved oxygen vertical distribution presents negative clinographic profile. The isolines in the aerated zone indicate good efficiency of oxygen transfer. In the polishing zone, concentrations above 2.0 mg/l were observed down to a depth of 1 m, possibly caused by photosynthetic activities.

scholarly journals Ice–ocean interaction and calving front morphology at two west Greenland tidewater outlet glaciers

2014 ◽  
Vol 8 (4) ◽  
pp. 1457-1468 ◽  
Author(s):  
N. Chauché ◽  
A. Hubbard ◽  
J.-C. Gascard ◽  
J. E. Box ◽  
R. Bates ◽  
...  
Keyword(s):  
Water Mass ◽  
Water Discharge ◽  
Greenland Ice Sheet ◽  
Bottom Layer ◽  
Atlantic Water ◽  
Tidewater Glaciers ◽  
Glacial Runoff ◽  
Primary Driver ◽  
Fresh Water Discharge ◽  
Multiple Interactions

Abstract. Warm, subtropical-originating Atlantic water (AW) has been identified as a primary driver of mass loss across the marine sectors of the Greenland Ice Sheet (GrIS), yet the specific processes by which this water mass interacts with and erodes the calving front of tidewater glaciers is frequently modelled and much speculated upon but remains largely unobserved. We present a suite of fjord salinity, temperature, turbidity versus depth casts along with glacial runoff estimation from Rink and Store glaciers, two major marine outlets draining the western sector of the GrIS during 2009 and 2010. We characterise the main water bodies present and interpret their interaction with their respective calving fronts. We identify two distinct processes of ice–ocean interaction which have distinct spatial and temporal footprints: (1) homogenous free convective melting which occurs across the calving front where AW is in direct contact with the ice mass, and (2) localised upwelling-driven melt by turbulent subglacial runoff mixing with fjord water which occurs at distinct injection points across the calving front. Throughout the study, AW at 2.8 ± 0.2 °C was consistently observed in contact with both glaciers below 450 m depth, yielding homogenous, free convective submarine melting up to ~200 m depth. Above this bottom layer, multiple interactions are identified, primarily controlled by the rate of subglacial fresh-water discharge which results in localised and discrete upwelling plumes. In the record melt year of 2010, the Store Glacier calving face was dominated by these runoff-driven plumes which led to a highly crenulated frontal geometry characterised by large embayments at the subglacial portals separated by headlands which are dominated by calving. Rink Glacier, which is significantly deeper than Store has a larger proportion of its submerged calving face exposed to AW, which results in a uniform, relatively flat overall frontal geometry.

scholarly journals Influence of temperature variability in the near-bottom layer on the results of geothermal measurements in the Kvitøya trough (Barents sea)

2019 ◽  
Vol 59 (4) ◽  
pp. 670-678
Author(s):  
E. A. Sukhikh ◽  
V. R. Akhmedzjanov ◽  
A. V. Ermakov
Keyword(s):  
Heat Flow ◽  
Water Temperature ◽  
Barents Sea ◽  
Temperature Fluctuations ◽  
Bottom Layer ◽  
Conductive Heat ◽  
Influence Of Temperature ◽  
The Barents Sea ◽  
Conductive Heat Flow ◽  
Thermal Variability

According to a study of the water column thermal variability in the Kvitøya trough (the northern part of the Barents Sea) substantial water temperature fluctuations in the near-bottom layer were found, both the seasonal and interannual, which affect the distribution of temperature in the upper layer of bottom sediments, and therefore the results of geothermal measurements. The contribution of temperature fluctuations on the water-sediments boundary to the values of the conductive heat flow measured during 25th cruise of the RV “Akademik Nikolaj Strakhov” was calculated. Endogenous heat flow was determined.

scholarly journals Water temperature in investigations of Polish lakes

2017 ◽  
Vol 17 (1) ◽  
pp. 31-46 ◽  
Author(s):  
Rajmund Skowron
Keyword(s):  
Surface Water ◽  
Water Temperature ◽  
Interwar Period ◽  
Water Mass ◽  
Thermal Conditions ◽  
Surface Water Temperature ◽  
Bottom Deposits ◽  
Basin Morphometry ◽  
The Vertical Distribution

Abstract Scientists became professionally interested in Polish lakes in the early 1850s. They focused predominantly upon the measurements of depth, observations of water stages, optical properties, and water temperature. The first systematic observations of surface water temperature were carried out in 1956. At present these measurements are conducted in 29 lakes. Investigations of the vertical distribution of water temperature were initiated in the interwar period and they contributed to a better recognition of the processes and factors conditioning dynamics of water masses. In general, measurements of water temperature have constituted fundamental observations with respect to the studies of yearly and daily courses of the temperature of surface water and the entire water mass, the influence of basin morphometry upon water thermal conditions, heat balance and heat resources, thermal conditions of bottom deposits and thermal classification of the lakes. The introduction of automatic gradient probes gave a new impulse to the investigations of water temperature in the lakes. The foundation of the Polish Limnological Society in 2001 and 18 national and international limnological conferences stimulated integration of the circle of limnologists. Specialist journals (Limnological Review, Studia Limnologica et Telmatologica) have presented around 40 publications with the leading theme of water temperature.

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