scholarly journals The Oceanography of Chatham Sound, British Columbia

1956 ◽  
Vol 13 (3) ◽  
pp. 385-434 ◽  
Author(s):  
Ronald W. Trites
Keyword(s):  
Pressure Gradient ◽  
Fresh Water ◽  
Coriolis Force ◽  
Coastal Waters ◽  
River Discharge ◽  
Average Data ◽  
Transverse Pressure ◽  
Frictional Forces ◽  
Oceanographic Data ◽  
Synoptic Observations

During May–September, 1948, an oceanographic study was made of Chatham Sound, primarily to determine, if possible, whether there was any obvious characteristic of the water in the region which could be correlated with the known migration of salmon to the spawning grounds up the Nass and Skeena Rivers. A detailed analysis of the oceanographic data is presented.The path taken by the fresh water through the sound is shown to depend on the volume of fresh water being discharged from the rivers. These reach their peak discharge in late May or early June and during this period the amount of fresh water in the sound is three to four times the average. Data obtained at anchor stations occupied for 10 to 40 hours indicate that there is a good correlation between tidal, salinity and temperature cycles.Dynamic calculations have been made of the velocities, total volume and fresh water transports. During normal river conditions, the agreement with observed velocities, and with fresh water discharges determined from gauge readings, suggests that even in these coastal waters there is an approximate balance between the transverse pressure gradient and the Coriolis force. Stations at the mouth of Portland Inlet exhibit an apparent balance at all times which suggests that transverse inertial and frictional forces are slight compared with the transverse pressure gradient and Coriolis force. Evidence of a variation in geopotential slope associated with the tides is proposed.The relatively large tidal amplitudes together with the wide and rapid fluctuations in river discharge make it exceedingly difficult to obtain reliable synoptic observations over the entire sound.

scholarly journals Productivity driven by Tana river discharge is spatially limited in Kenyan coastal waters

2021 ◽  
Vol 211 ◽  
pp. 105713
Author(s):  
Damaris Mutia ◽  
Stephen Carpenter ◽  
Zoe Jacobs ◽  
Fatma Jebri ◽  
Joseph Kamau ◽  
...  
Keyword(s):  
Coastal Waters ◽  
River Discharge ◽  
Tana River

scholarly journals Analytical approach for determining the mean water level profile in an estuary with substantial fresh water discharge

2016 ◽  
Vol 20 (3) ◽  
pp. 1177-1195 ◽  
Author(s):  
Huayang Cai ◽  
Hubert H. G. Savenije ◽  
Chenjuan Jiang ◽  
Lili Zhao ◽  
Qingshu Yang
Keyword(s):  
Water Level ◽  
Fresh Water ◽  
River Discharge ◽  
River Flow ◽  
Water Discharge ◽  
Value Theory ◽  
Velocity Amplitude ◽  
Mean Water Level ◽  
The Mean ◽  
Fresh Water Discharge

Abstract. The mean water level in estuaries rises in the landward direction due to a combination of the density gradient, the tidal asymmetry, and the backwater effect. This phenomenon is more prominent under an increase of the fresh water discharge, which strongly intensifies both the tidal asymmetry and the backwater effect. However, the interactions between tide and river flow and their individual contributions to the rise of the mean water level along the estuary are not yet completely understood. In this study, we adopt an analytical approach to describe the tidal wave propagation under the influence of substantial fresh water discharge, where the analytical solutions are obtained by solving a set of four implicit equations for the tidal damping, the velocity amplitude, the wave celerity, and the phase lag. The analytical model is used to quantify the contributions made by tide, river, and tide–river interaction to the water level slope along the estuary, which sheds new light on the generation of backwater due to tide–river interaction. Subsequently, the method is applied to the Yangtze estuary under a wide range of river discharge conditions where the influence of both tidal amplitude and fresh water discharge on the longitudinal variation of the mean tidal water level is explored. Analytical model results show that in the tide-dominated region the mean water level is mainly controlled by the tide–river interaction, while it is primarily determined by the river flow in the river-dominated region, which is in agreement with previous studies. Interestingly, we demonstrate that the effect of the tide alone is most important in the transitional zone, where the ratio of velocity amplitude to river flow velocity approaches unity. This has to do with the fact that the contribution of tidal flow, river flow, and tide–river interaction to the residual water level slope are all proportional to the square of the velocity scale. Finally, we show that, in combination with extreme-value theory (e.g. generalized extreme-value theory), the method may be used to obtain a first-order estimation of the frequency of extreme water levels relevant for water management and flood control. By presenting these analytical relations, we provide direct insight into the interaction between tide and river flow, which will be useful for the study of other estuaries that experience substantial river discharge in a tidal region.

scholarly journals SPECIES COMPOSITION AND DIVERSITY OF TIDAL TRAP NET CATCHES IN THE WATERS OF INDRAGIRI HILIR, RIAU, INDONESIA

2017 ◽  
Vol 7 (1) ◽  
pp. 47
Author(s):  
Badrudin Badrudin ◽  
Bambang Sumiono ◽  
T.S Murtoyo
Keyword(s):  
Species Composition ◽  
Fresh Water ◽  
Coastal Waters ◽  
Water Discharge ◽  
Fresh Water Discharge

The coastal waters of the eastern part of lndragiri Hilir, Riau, which are mostly estuarine, are influenced by the huge fresh water discharge and are usually fertile.

scholarly journals Zonal Momentum Balance in the Tropical Atmospheric Circulation during the Global Monsoon Mature Months

2013 ◽  
Vol 70 (2) ◽  
pp. 583-599 ◽  
Author(s):  
Wenchang Yang ◽  
Richard Seager ◽  
Mark A. Cane
Keyword(s):  
Angular Momentum ◽  
Pressure Gradient ◽  
Atmospheric Circulation ◽  
Coriolis Force ◽  
Gradient Force ◽  
Pressure Gradient Force ◽  
Global Monsoon ◽  
Upper Troposphere ◽  
Nonlinear Advection ◽  
Zonal Momentum

Abstract In this paper, zonal momentum balances of the tropical atmospheric circulation during the global monsoon mature months (January and July) are analyzed in three dimensions based on the ECMWF Interim Re-Analysis (ERA-Interim). It is found that the dominant terms in the balance of the atmospheric boundary layer (ABL) in both months are the pressure gradient force, the Coriolis force, and friction. The nonlinear advection term plays a significant role only in the Asian summer monsoon regions within the ABL. In the upper troposphere, the pressure gradient force, the Coriolis force, and the nonlinear advection are the dominant terms. The transient eddy force and the residual force (which can be explained as convective momentum transfer over open oceans) are secondary, yet cannot be neglected near the equator. Zonal-mean equatorial upper-troposphere easterlies are maintained by the absolute angular momentum advection associated with the cross-equatorial Hadley circulation. Equatorial upper-troposphere easterlies over the Asian monsoon regions are also controlled by the absolute angular momentum advection but are mainly maintained by the pressure gradient force in January. The equivalent linear Rayleigh friction, which is widely applied in simple tropical models, is calculated and the corresponding spatial distribution of the local coefficient and damping time scale are estimated from the linear regression. It is found that the linear momentum model is in general capable of crudely describing the tropical atmospheric circulation dynamics, yet the caveat should be kept in mind that the friction coefficient is not uniformly distributed and is even negative in some regions.

Estimating Annual River Discharge And Nitrogen Loadings To Danish Coastal Waters

2003 ◽  
Vol 60 (2) ◽  
pp. 179-197 ◽  
Author(s):  
Dirk-Ingmar MÜller-Wohlfeil ◽  
Brian Kronvang ◽  
SØren Erik Larsen ◽  
Niels Behring Ovesen
Keyword(s):  
Coastal Waters ◽  
River Discharge ◽  
Nitrogen Loadings

A NEW PROCEDURE ALLOWING REPLICATED MINIATURE LARVICIDE TESTS IN A LARGE RIVER

1969 ◽  
Vol 101 (7) ◽  
pp. 713-725 ◽  
Author(s):  
F. J. H. Fredeen
Keyword(s):  
Fresh Water ◽  
River Discharge ◽  
Aquatic Invertebrates ◽  
River Pollution ◽  
Large River ◽  
Special Equipment ◽  
Recovery Rates ◽  
Combining Data ◽  
Concentrated Milk ◽  
St Lawrence River

AbstractDDT and DDD emulsifiable formulations were tested against aquatic invertebrates in small plots in rapids in the St. Lawrence River. Pollution was minimal; less than 0.0044% of the river discharge was treated in each rest.The weakest dosage of DDD, 0.8 p.p.m.-minutes, disabled many Trichoptera and Diptera; the strongest, 12.0 p.p.m.-minutes, did not eliminate any one Order of insects except perhaps Plecoptera. A dosage of 6.0 p.p.m.-minutes was selected for tests on a larger scale against shadfly larvae (mainly Trichoptera). Net-spinning Trichoptera were more sensitive than case-bearers. Of the non-insect organisms, amphipods were relatively sensitive but their populations were rapidly restored by immigration. Oligochaetes and molluscs were least affected.The use of small plots in a large river required special equipment and techniques: a larvicide dispenser (to be described separately), the use of concentrated milk as a dye to aid in the survey of plot boundaries, the transfer of disabled organisms to fresh water to compare recovery rates, and a formula combining data from samples of both disabled and surviving organisms to estimate per cent kill.

Competing 3D Mechanisms in Compressor Flows

2015 ◽  
Author(s):  
James V. Taylor ◽  
Robert J. Miller
Keyword(s):  
Pressure Gradient ◽  
Design Space ◽  
Flow Direction ◽  
Three Dimensional ◽  
Transverse Pressure ◽  
Compressor Design ◽  
Design Systems ◽  
3D Stacking ◽  
Profile Loss ◽  
Different Levels

Even though three-dimensional design is central to all modern compressor design systems, many of these methods still rely, at the their core on a two-dimensional, sectional, view of blade aerodynamics. This paper argues that this view fundamentally limits design by not correctly considering the way in which pressure gradient transverse to the flow direction affects both separation and loss. The first part of the paper details how 3D blade stacking and the transverse pressure gradient fundamentally alters the behaviour of the corner separations and trailing edge separations. By controlling this design parameter it is possible to switch between the two. The transverse pressure gradient is also shown to be responsible for a substantial increase in profile loss. In the second part this understanding is used to explore the uncertainty of the design space by simultaneously varying pitch-chord ratio and 3D stacking. It is shown that the design space is split in half by two different levels of risk.

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