Characteristics of Three-layer Circulation and inverse Surface Salinity Gradients in Two Small Semi-enclosed Danish Embayments

1981 ◽  
Vol 12 (2) ◽  
pp. 119-128 ◽  
Author(s):  
Chr Christiansen ◽  
H. Christoffersen ◽  
S. Lomhott
Keyword(s):  
Fresh Water ◽  
Coastal Upwelling ◽  
Shallow Waters ◽  
Salinity Distribution ◽  
Surface Salinity ◽  
Salinity Gradients ◽  
Tidal Modification

Inverse surface salinity gradients were measured in two small Danish embayments. Three possible mechanisms are taken into account. In Knebel Vig the circulation and salinity distribution can be generated by tidal modification of the stratification at the entrance which is maintained by external dynamics rather than by fresh water discharged into the embayment. In Egens Vig the involved mechanisms can be coastal upwelling and difference in heating between shallow waters near the coast and deeper waters in the central part of the embayment.

Ocean Salinity Aspects of the Ningaloo Niño

2021 ◽  
pp. 1
Author(s):  
Yaru Guo ◽  
Yuanlong Li ◽  
Fan Wang ◽  
Yuntao Wei
Keyword(s):  
Fresh Water ◽  
Large Scale ◽  
Southern Oscillation ◽  
Regional Climate ◽  
Ocean Model ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
Surface Salinity ◽  
Near Surface ◽  
Ocean Salinity

AbstractNingaloo Niño – the interannually occurring warming episode in the southeast Indian Ocean (SEIO) – has strong signatures in ocean temperature and circulation and exerts profound impacts on regional climate and marine biosystems. Analysis of observational data and eddy-resolving regional ocean model simulations reveals that the Ningaloo Niño/Niña can also induce pronounced variability in ocean salinity, causing large-scale sea surface salinity (SSS) freshening of 0.15–0.20 psu in the SEIO during its warm phase. Model experiments are performed to understand the underlying processes. This SSS freshening is mutually caused by the increased local precipitation (~68%) and enhanced fresh-water transport of the Indonesian Throughflow (ITF; ~28%) during Ningaloo Niño events. The effects of other processes, such as local winds and evaporation, are secondary (~18%). The ITF enhances the southward fresh-water advection near the eastern boundary, which is critical in causing the strong freshening (> 0.20 psu) near the Western Australian coast. Owing to the strong modulation effect of the ITF, SSS near the coast bears a higher correlation with the El Niño-Southern Oscillation (0.57, 0.77, and 0.70 with Niño-3, Niño-4, and Niño-3.4 indices, respectively) than sea surface temperature (-0.27, -0.42, and -0.35) during 1993-2016. Yet, an idealized model experiment with artificial damping for salinity anomaly indicates that ocean salinity has limited impact on ocean near-surface stratification and thus minimal feedback effect on the warming of Ningaloo Niño.

scholarly journals Response of the Snowy River Estuary to two environmental flows

2015 ◽  
Vol 127 (2) ◽  
pp. 28
Author(s):  
Errol J. McLean ◽  
Jon B. Hinwood
Keyword(s):  
Fresh Water ◽  
Peak Flow ◽  
Environmental Flows ◽  
River Estuary ◽  
Environmental Flow ◽  
River Channel ◽  
Salinity Gradients ◽  
Tasman Sea ◽  
Eastern Australia ◽  
Major River

The Snowy River is a major river in south-eastern Australia, discharging to the Tasman Sea via a barrier estuary, with its entrance constricted by marine sands. Since the construction of the Snowy Mountains Scheme, river flows have not been sufficient to maintain the river channel. A program of environmental flow releases (EFR) is returning water to the river to restore the fluvial reaches and is now trialling flow regimes that may also benefit the estuarine reaches. This paper documents the response of the estuarine segments of the Snowy River to two EFRs; the release in 2010 was designed to scour the upper reaches of the Snowy River while the larger 2011 release was intended to extend the scouring downstream. For each release, the effects on the entrance morphology, tides and salinity through the flow peak and recovery are described. Each EFR caused minor increases in depth and very minor longshore movement of the entrance channel, although each EFR had been preceded by a larger fresh flow that would have scoured the channels. The small increase in fresh water inflow in the 2010 EFR pushed salinity contours seawards and steepened vertical salinity gradients. The larger inflow in the 2011 EFR purged the upper estuary of saltwater. After the peak flow, salinity recovery was rapid in the principal estuarine channels but took weeks where poorly connected wetlands could store fresh flood waters. Critical flows for scouring the entrance and purging salinity are estimated.

Meltwater Discharge to the Skagerrak–Kattegat from the Baltic Ice Lake during the Younger Dryas Interval

1998 ◽  
Vol 49 (3) ◽  
pp. 264-270 ◽  
Author(s):  
Hui Jiang ◽  
Nils-Olof Svensson ◽  
Svante Björck
Keyword(s):  
Younger Dryas ◽  
Sea Surface Salinity ◽  
Large Area ◽  
Surface Salinity ◽  
Swedish West Coast ◽  
Norwegian Sea ◽  
Environmental Interpretation ◽  
Salinity Gradients ◽  
Surface Water Salinity ◽  
The Baltic

Diatom data from the Skagerrak–Kattegat show that large amounts of meltwater were discharged into the Kattegat–Skagerrak from the Baltic Ice Lake during the Younger Dryas interval. Strong meltwater discharge greatly freshened surface-water salinity in the Kattegat and areas along the Swedish west coast and possibly changed the directions of sea-surface salinity gradients from north–south to east–west or northwest–southeast. It resulted in a markedly stratified water column in salinity in the Kattegat, which complicates the environmental interpretation based on different types of microfossils. The meltwater influence on the large area of the Skagerrak during the Younger Dryas was, however, restricted along the Norwegian coast where it flowed into the Norwegian Sea.

scholarly journals Satellite and Argo Observed Surface Salinity Variations in the Tropical Indian Ocean and Their Association with the Indian Ocean Dipole Mode

2015 ◽  
Vol 28 (2) ◽  
pp. 695-713 ◽  
Author(s):  
Yan Du ◽  
Yuhong Zhang
Keyword(s):  
Indian Ocean ◽  
Ocean Circulation ◽  
Indian Ocean Dipole ◽  
Coastal Upwelling ◽  
Tropical Indian Ocean ◽  
Sea Surface Salinity ◽  
The South ◽  
Surface Salinity ◽  
Indian Ocean Dipole Mode ◽  
The Indian Ocean

Abstract This study investigates sea surface salinity (SSS) variations in the tropical Indian Ocean (IO) using the Aquarius/Satelite de Aplicaciones Cientificas-D (SAC-D) and the Soil Moisture and Ocean Salinity (SMOS) satellite data and the Argo observations during July 2010–July 2014. Compared to the Argo observations, the satellite datasets generally provide SSS maps with higher space–time resolution, particularly in the regions where Argo floats are sparse. Both Aquarius and SMOS well captured the SSS variations associated with the Indian Ocean dipole (IOD) mode. Significant SSS changes occurred in the central equatorial IO, along the Java–Sumatra coast, and south of the equatorial IO, due to ocean circulation variations. During the negative IOD events in 2010, 2013, and 2014, westerly wind anomalies strengthened along the equator, weakening coastal upwelling off Java and Sumatra and decreasing SSS. South of the equatorial IO, an anomalous cyclonic gyre changed the tropical circulation, which favored the eastward high-salinity tongue along the equator and the westward low-saline tongue in the south. An upwelling Rossby wave favored the increase of SSS farther to the south. During the positive IOD events in 2011 and 2012, the above-mentioned processes reversed, although the decrease of SSS was weaker in magnitude.

scholarly journals On the Possible Mechanisms for Saltening of the Bay of Bengal

2019 ◽  
Vol 69 (1) ◽  
pp. 93-103
Author(s):  
Anoopa Prasad C ◽  
P.V. Hareesh Kumar
Keyword(s):  
Bay Of Bengal ◽  
Arabian Sea ◽  
Coastal Upwelling ◽  
Salt Water ◽  
Dominant Role ◽  
Salinity Gradient ◽  
Ekman Transport ◽  
Surface Salinity ◽  
Near Shore ◽  
Lateral Advection

The Bay of Bengal (BoB) is a low saline basin owing to large influx of freshwater from precipitation and river runoff. To maintain the salt balance of the BoB, the incessant lowering of salinity is to be balanced by the inflow of saltier water into the basin. In the present work, various processes that contribute to the saltening of the BoB, viz. coastal upwelling, eddies and their interaction, lateral advection from Arabian Sea and tropical cyclones are discussed. In the near-shore regions, the coastal upwelling due to wind induced Ekman transport plays a dominant role in increasing the surface salinity. On the other hand, in the open ocean, the divergence induced by eddies and their mutual interaction contributes significantly to the salt water pumping. In the southern BoB, the advection from the Arabian Sea increases the salinity. The formation of cyclones in the BoB also leads to an increase in the surface salinity. However, the magnitude of saltening of the Bay due to these processes varies from north to south. The uplift of saltier water from subsurface levels increases the salinity in the surface layers thereby creating a salinity gradient and a salinity front.

scholarly journals Sea Surface Salinity Distribution in the Southern Ocean as Observed From Space

2019 ◽  
Vol 124 (5) ◽  
pp. 3186-3205 ◽  
Author(s):  
Cynthia Garcia‐Eidell ◽  
Josefino C. Comiso ◽  
Emmanuel Dinnat ◽  
Ludovic Brucker
Keyword(s):  
Southern Ocean ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
Salinity Distribution ◽  
Surface Salinity

scholarly journals Investigation of Salt Intrusion Condition in the Belat Estuary

2018 ◽  
Vol 150 ◽  
pp. 03005
Author(s):  
Jacqueline Isabella Gisen ◽  
Siti Syuhaida Adnan ◽  
Ahmad Amirul Ahmad Tajudin ◽  
Tian Xian Chan
Keyword(s):  
Fresh Water ◽  
Water Intake ◽  
Sea Water ◽  
Water Discharge ◽  
Spring Tide ◽  
Salinity Distribution ◽  
Salt Intrusion ◽  
Conducting Salt ◽  
High Precipitation ◽  
Fresh Water Discharge

Awareness on salt intrusion problem is still lacking in Malaysia due to high precipitation in the region. However, the El-Nino phenomenon that occurred recently has caused extremely low fresh water discharge in the Kuantan River which allowed the sea water to intrude further into its water intake region. Consequently, the Belat River may become potential water resources alternative to build new water intake station for the water supply in the Kuantan River Basin. The aims of this study are to: 1) investigate the salinity distribution in the Belat Estuary; 2) evaluate the applicability of the 1-D analytical salt intrusion solution; 3) determine the calibration parameters in the salt intrusion model. Salt intrusion measurements was conducted during the dry season at spring tide when the fresh water discharge is the minimum. Collection of data such as hydrological data, river cross section and salinity were collected to be used in the salt intrusion analysis. The results obtained show good agreement between the simulated and observed salinity distribution in the estuary with low RMSE and high NSE values. This indicates that the model is reliable and can become an important tool for water manager in conducting salt intrusion study for this area.

scholarly journals A Conceptual Model of the Surface Salinity Distribution in the Oceanic Hadley Cell

2008 ◽  
Vol 21 (24) ◽  
pp. 6586-6598 ◽  
Author(s):  
Johan Nilsson ◽  
Heiner Körnich
Keyword(s):  
Conceptual Model ◽  
Hadley Cell ◽  
Ekman Transport ◽  
Specific Humidity ◽  
Salinity Range ◽  
Salinity Distribution ◽  
Surface Salinity ◽  
Near Surface ◽  
Salinity Variation ◽  
Meridional Overturning

Abstract A conceptual model of the salinity distribution in the oceanic Hadley cell is presented. The model pertains to the region of tropical easterly surface winds, where the surface salinity increases poleward from a local salinity minimum near the equator to a subtropical salinity maximum. A fundamental constraint is that the meridional freshwater transports in the atmosphere and the ocean have the same magnitude but opposite directions. A key assumption is that the strength of the meridional overturning cells in the atmosphere and the ocean is proportional and set by the surface layer Ekman transport. It is further assumed that, to the lowest order of approximation, the zonal-mean Ekman transports accomplish the meridional freshwater transports, that is, eddy fluxes and gyre-induced transports are ignored. The model predicts that the salinity variation in the oceanic cell is directly proportional to the specific humidity of the near-surface air, but independent of the meridional mass transport (as long as the atmospheric and oceanic mass transports remain proportional). If the relative humidity of the near-surface air is constant, the salinity variation in the oceanic Hadley cell varies essentially with the surface temperature according to the Clausius–Clapeyron expression for the saturation vapor pressure. Further, the model is compared to observations and a global warming simulation and found to give a leading-order description of the tropical surface salinity range.

Characteristics of Temperature and Salinity Distribution in the Wonorejo Estuary, Surabaya, Based on Field Measurement

2017 ◽  
Vol 862 ◽  
pp. 102-106
Author(s):  
Anita Diah Pahlewi ◽  
Suntoyo ◽  
Wahyudi ◽  
Muhammad Taufik
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Vertical Mixing ◽  
Pollutant Dispersion ◽  
Bottom Layer ◽  
Water Area ◽  
Water Circulation ◽  
Salinity Distribution ◽  
Salinity Increase ◽  
Longitudinal Position

Wonorejo waters have a significant value, both economically and socially. One of ecosystem that have close relationships with Wonorejo waters is Estuary. Temperature and salinity have role in water circulation, where the water circulation have impact to some organism distribution and pollutant dispersion. The purpose of this study is to investigate the characteristic of temperature and salinity distribution in Wonorejo Estuary body’s water. Furthermore, it can be used for determining the type of Wonorejo Estuary. The observation has been done at Wonorejo Estuary in August 2015 to measure the vertical and horizontal temperature and salinity distribution. The measurement of temperature and salinity used Conductivity, Salinity, Temperature tool by YSI. The result show that commonly the temperature and salinity vertical profile are almost similar from surface layer until the bottom layer. But they have trend where the salinity increase, while the temperature decrease to the water depth. There is no thermocline layer due to the shallow water area, it is so from the upper layer until the bottom layer still influenced by dragforce and the vertical mixing between fresh water and sea water occurs. The horizontal temperature distribution in the open sea surface tend to zonation, which is not depend to longitudinal position. The salinity value in each depth are not change obviously indicate that there is a vertical well mixed between fresh water and sea water.

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