NUTRIENT RETENTION IN THE BIOREMEDIATION ZONE OF A SANDY BEACH

1995 ◽  
Vol 1995 (1) ◽  
pp. 896-897
Author(s):  
Brian A. Wrenn ◽  
Makram T. Suidan ◽  
Kevin L. Strohmeier ◽  
B. Loye Eberhardt ◽  
Gregory J. Wilson ◽  
...  
Keyword(s):  
Tidal Cycle ◽  
Sandy Beach ◽  
Neap Tide ◽  
High Tide ◽  
Spring Tide ◽  
Nutrient Retention ◽  
Delaware Bay ◽  
Low Energy ◽  
Washout Rate ◽  
Tracer Study

ABSTRACT A tracer study was conducted on a low-energy beach in Delaware Bay to determine how the nutrient washout rate is affected by the tidal cycle. When tracer was applied during spring tide, it was reduced to background levels following a single high tide; but when it was applied during neap tide, tracer persisted in the bioremediation zone for a much longer time. The washout rate was found to be related to the extent of water coverage during high tide.

scholarly journals Variation of water mass exchange on tidal scale in Balikpapan Bay

2021 ◽  
Vol 925 (1) ◽  
pp. 012013
Author(s):  
I P Anwar ◽  
M R Putri ◽  
A Tarya ◽  
I Mandang
Keyword(s):  
Mass Exchange ◽  
River Runoff ◽  
Water Mass ◽  
Model Simulation ◽  
Neap Tide ◽  
Saline Water ◽  
High Tide ◽  
Spring Tide ◽  
Salt Transport ◽  
Water Mass Exchange

Abstract Balikpapan Bay is enclosed water influenced by freshwater from river runoff and saline water from Makassar Strait. The exchange of water mass was examined by 3D numerical model simulation-Hamburg Shelf Ocean Model (HAMSOM) with horizontal resolutions approx. 150 m and 10 vertical layers applied in Balikpapan Bay. The thirteen tidal components, daily river runoff, atmospheric forcing, subsurface temperature, and Salinity in 3D used for model input. The tidal elevation from Geospatial Information Agency (BIG) model fits with this result from 01/03/2020 to 31/03/2020. It has coefficient correlation 0,99 with a significant level of 95% and Root Mean Square Error (RMSE) is 0,1 m. The volume and salt transport in the mouth (Line-A) and middle (Line-B) of bay was examined. The maximum transport in Line-A during spring (neap) high to low tide and low to high tide is −18364.72 m3/s (−1717.57 m3/s) and −17532.27 m3/s (4258.86 m3/s) for volume. Then, 531,947,898.90 kg.psu./s (−45,127,135.38 kg.psu./s) and −536,410,944.50 kg.psu./s (140,700,437.97 kg.psu./s) for salinity. Positive (negative) of water transport is inflow (outflow) to Balikpapan Bay. The net transport in a day during the spring (neap) is −832.45 m3/s (5976.43 m3/s) for volume and −4,463,045.58 kg.psu./s (185,827,573.35 kg.pau./s) for salt. The vertical structure of net volume and salt transport bot in Line-A and Line-B shows the water goes to outer bay in surface and inner bay in subsurface. While in the spring tide the surface deeper than neap tide. It indicated that water mass exchange dominantly influenced by river in surface and tidal in subsurface. It also shows that water mass from inner bay more easy flushing during spring tide than neap tide and vice versa

Tree-climbing behaviour of Cerithidea decollata, a western Indian Ocean mangrove gastropod (Mollusca: Potamididae)

2006 ◽  
Vol 86 (6) ◽  
pp. 1429-1436 ◽  
Author(s):  
Marco Vannini ◽  
Rocco Rorandelli ◽  
Outi Lähteenoja ◽  
Elisha Mrabu ◽  
Sara Fratini
Keyword(s):  
Indian Ocean ◽  
Neap Tide ◽  
High Tide ◽  
Spring Tide ◽  
Western Indian Ocean ◽  
High Water ◽  
Avicennia Marina ◽  
Single Individual ◽  
Night Time ◽  
Mangrove Tree

The behaviour of Cerithidea decollata, a common western Indian Ocean mangrove tree climbing gastropod, was studied in Mida Creek, Kenya. At the study site, this snail mainly lived in Avicennia marina dominated areas, i.e. in the mangrove belt between high water spring tide and high water neap tide levels. Not a single individual was found on the less common mangrove tree Lumnitzera racemosa, living just above the A. marina level (together with terrestrial grass), and was very rarely recorded on the common Rhizophora mucronata, bordering the seaward side of the A. marina belt. No significant gradient of C. decollata density was found within the whole 150–200 m wide belt. The majority of C. decollata rested on tree trunks during high tide, creeping on the mud flat below the tree for part of low tide, and returning on the trunks well before being reached by the water. This migratory pattern was more evident at spring than at neap tide, at day than at night time and it was strongly influenced by the shore level of the mangrove zone in which animals resided. While C. decollata from lower shore levels neatly massively migrated twice a day, individuals from upper levels showed a more continuous and irregular activity, sometimes crawling on the mud even at high water of spring tide, when they experience just a few centimetres of water for no more than one to two hours.

scholarly journals Model Hidrodinamika Pasang Surut di Perairan Pesisir Barat Kabupaten Badung, Bali

2016 ◽  
Vol 2 (2) ◽  
pp. 54
Author(s):  
Made Narayana Adibhusana ◽  
I Gede Hendrawan ◽  
I Wayan Gede Astawa Karang
Keyword(s):  
Sea Level ◽  
West Coast ◽  
Current Velocity ◽  
Neap Tide ◽  
High Tide ◽  
Spring Tide ◽  
The West ◽  
Current Vector ◽  
Sea Current ◽  
Sea Currents

Finite Volume Coastal Ocean Model (FVCOM) is using for numerical modeling of hydrodynamic tidal water in west coast of Badung regency, Bali. The model result is validation with field observations data in the area using the equation Root Mean Square Error (RMSE). Field tidal data elevation of sea level elevation measurements were obtained by using the palm of tidal. Field data speed and direction of sea currents obtained using Lagrangian method. Excellent results obtained with RMSE values tidal elevation of sea level by 0.24 m dan RMSE values for sea current is 0.125 m/s. The results of model simulations show sea current patterns in the waters of the west coast of Badung regency, Bali relatively the same at the spring tide and neap tide conditions. The pattern of sea currents at high tide shows current vector that moves in toward the water of the west coast of Badung regency area from Bali Strait and the Indian Ocean. At the time of low tide sea current vector movement towards Bali Strait and the India Ocean. Sea current velocity in the eastern waters of the west coast of Badung regency (longitude of 115,05°– 115,17°) is higher than the sea current velocity in western waters area (longitude of 114,95°– 115,05°). Sea current velocity in the waters of the west coast of Badung regency on the condition of the spring tide range from 0.005 to 0.025 m/s, on the other side the sea current velocity on the neap tide conditions range from 0.005 to 0.012 m/s.

scholarly journals Influence of Tidal Inundation on CO<sub>2</sub> Exchange between Salt Marshes and the Atmosphere

2017 ◽  
Author(s):  
Hafsah Nahrawi ◽  
Monique Y. Leclerc ◽  
Gengsheng Zhang ◽  
Roshani Pahari
Keyword(s):  
Eddy Covariance ◽  
Salt Marshes ◽  
Neap Tide ◽  
High Tide ◽  
Spring Tide ◽  
Co2 Exchange ◽  
Eddy Covariance Method ◽  
Set Up ◽  
Carbon Dioxide Co2 ◽  
Reduction Of Co2

Abstract. Salt marshes are among the most productive and dynamic ecosystems on Earth and globally sequester an average of 210 g C m−2 yr−1. To understand the role of this ecosystem in the carbon cycle and its changes as a result of rapid climate change and human disturbance, a baseline record particularly on carbon dioxide (CO2) exchange between this ecosystem and atmosphere needs to be established. The goal of this study is to determine the effects tide events on the exchange of CO2 in a salt marsh ecosystem dominated by Spartina alterniflora using the eddy-covariance method near Sapelo Island, GA. Two eddy-covariance systems were set up in July 2013 to capture 10 Hz data of CO2. Results show that during daytime high tide events, a reduction of CO2 exchange was observed. The conditions with a high tide to vegetation ratio had smaller CO2 exchange when compared to conditions with a low tide ratio. Total daytime monthly reduction of CO2 exchange for August 2014 was 15 %. A greater total reduction of CO2 exchange of 40 % was recorded for high tide events with tide ratio of 0.75–1.0. In comparison of the effect of neap tide and spring tide on CO2 exchange, neap tide days showed a greater CO2 exchange as compared to spring tide days for May and October 2014, respectively. The inclusion of such results has implications to quantify the carbon budget and its changes as sea level rises.

scholarly journals A Numerical Study of Salt Fluxes in Delaware Bay Estuary

2013 ◽  
Vol 43 (8) ◽  
pp. 1572-1588 ◽  
Author(s):  
María Aristizábal ◽  
Robert Chant
Keyword(s):  
River Discharge ◽  
Neap Tide ◽  
Numerical Study ◽  
Spring Tide ◽  
Delaware Bay ◽  
Salt Flux ◽  
Exchange Flow ◽  
Regional Ocean Modeling System ◽  
Salinity Field ◽  
Estuarine Exchange

Abstract The results of a numerical study of Delaware Bay using the Regional Ocean Modeling System (ROMS) are presented. The simulations are run over a range of steady river inputs and used M2 and S2 tidal components to capture the spring–neap variability. Results provide a description of the spatial and temporal structure of the estuarine exchange flow and the salinity field, as well the along-channel salt flux in the estuary. The along-channel salt flux is decomposed into an advective term associated with the river flow, a steady shear dispersion Fe associated with the estuarine exchange flow, and a tidal oscillatory salt flux Ft. Time series of Fe and Ft show that both are larger during neap tide than during spring. This time variability of Ft, which is contrary to existing scalings, is caused by the lateral flows that bring velocity and salinity out of quadrature and the stronger stratification during neap tide, which causes Ft to be enhanced relative to spring tide. A fit for the salt intrusion length L with river discharge Q for a number of isohalines is performed. The functional dependences of L with Q are significantly weaker than Q−1/3 scaling. It is concluded that the response of the salt field with river discharge is due to the dependence of Fe and Ft with Q and the relative importance of Ft to the total upstream salt flux: as river discharge increases, Fe becomes the dominant mechanism. Once Fe dominates, the salt field stiffens because of a reduction of the vertical eddy viscosity with increasing Q.

scholarly journals Tidal variability of nutrients in a coastal coral reef system influenced by groundwater

2018 ◽  
Vol 15 (4) ◽  
pp. 997-1009 ◽  
Author(s):  
Guizhi Wang ◽  
Shuling Wang ◽  
Zhangyong Wang ◽  
Wenping Jing ◽  
Yi Xu ◽  
...  
Keyword(s):  
Coral Reef ◽  
Water Column ◽  
Water Depth ◽  
Neap Tide ◽  
Groundwater Discharge ◽  
Spring Tide ◽  
Biological Processes ◽  
Reef System ◽  
Nitrite Nitrate ◽  
Coral Reef System

Abstract. To investigate variation in nitrite, nitrate, phosphate, and silicate in a spring–neap tide in a coral reef system influenced by groundwater discharge, we carried out a time-series observation of these nutrients and 228Ra, a tracer of groundwater discharge, in the Luhuitou fringing reef at Sanya Bay in the South China Sea. The maximum 228Ra, 45.3 dpm 100 L−1, appeared at low tide and the minimum, 14.0 dpm 100 L−1, appeared during a flood tide in the spring tide. The activity of 228Ra was significantly correlated with water depth and salinity in the spring–neap tide, reflecting the tidal-pumping feature of groundwater discharge. Concentrations of all nutrients exhibited strong diurnal variation, with a maximum in the amplitude of the diel change for nitrite, nitrate, phosphate, and silicate in the spring tide of 0.46, 1.54, 0.12, and 2.68 µM, respectively. Nitrate and phosphate were negatively correlated with water depth during the spring tide but showed no correlation during the neap tide. Nitrite was positively correlated with water depth in the spring and neap tide due to mixing of nitrite-depleted groundwater and nitrite-rich offshore seawater. They were also significantly correlated with salinity (R2  ≥  0.9 and P < 0.05) at the ebb flow of the spring tide, negative for nitrate and phosphate and positive for nitrite, indicating the mixing of nitrite-depleted, nitrate- and phosphate-rich less saline groundwater and nitrite-rich, nitrate- and phosphate-depleted saline offshore seawater. We quantified variation in oxidized nitrogen (NOx) and phosphate contributed by biological processes based on deviations from mixing lines of these nutrients. During both the spring and neap tide biologically contributed NOx and phosphate were significantly correlated with regression slopes of 4.60 (R2  =  0.16) in the spring tide and 13.4 (R2  =  0.75) in the neap tide, similar to the composition of these nutrients in the water column, 5.43 (R2  =  0.27) and 14.2 (R2  =  0.76), respectively. This similarity indicates that the composition of nutrients in the water column of the reef system was closely related with biological processes during both tidal periods, but the biological influence appeared to be less dominant, as inferred from the less significant correlations (R2  =  0.16) during the spring tide when groundwater discharge was more prominent. Thus, the variability of nutrients in the coral reef system was regulated mainly by biological uptake and release in a spring–neap tide and impacted by mixing of tidally driven groundwater and offshore seawater during spring tide.

scholarly journals Using flushing rate to investigate spring-neap and spatial variations of gravitational circulation and tidal exchanges in an estuary

2010 ◽  
Vol 14 (8) ◽  
pp. 1465-1476 ◽  
Author(s):  
D. C. Shaha ◽  
Y.-K. Cho ◽  
G.-H. Seo ◽  
C.-S. Kim ◽  
K. T. Jung
Keyword(s):  
Neap Tide ◽  
Spring Tide ◽  
Vertical Mixing ◽  
River Estuary ◽  
Spatial Variations ◽  
Tidal Amplitude ◽  
Gravitational Circulation ◽  
Flushing Rate ◽  
Rapid Exchange ◽  
Dispersive Flux

Abstract. Spring-neap and spatial variations of gravitational circulation and tidal exchanges in the Sumjin River Estuary (SRE) were investigated using the flushing rate. The flushing rate was calculated between multiple estuarine segments and the adjacent bay to examine the spatial variation of two exchanges. The strength of gravitational circulation and tidal exchanges modulated significantly between spring and neap tides, where stratification alternated between well-mixed and highly-stratified conditions over the spring-neap cycle. Tide-driven dispersive flux of salt dominated over gravitational circulation exchange near the mouth during spring tide due to the larger tidal amplitude that caused well-mixed conditions and rapid exchange. In contrast, the central and inner regimes were found to be partially stratified during spring tide due to the reduction in tidal amplitude where both gravitational circulation and tidal exchanges were important in transporting salt. The combined contributions of two fluxes were also found during neap tide along the SRE due to the significant reduction in vertical mixing that accompanied strong stratification. Gravitational circulation exchange almost entirely dominated in transporting salt at the upstream end during spring and neap tides.

scholarly journals Comparison of empirical models with intensively observed data for prediction salt intrusion in the Sumjin River estuary, Korea

2009 ◽  
Vol 6 (2) ◽  
pp. 1879-1905 ◽  
Author(s):  
D. C. Shaha ◽  
Y.-K. Cho
Keyword(s):  
River Discharge ◽  
Neap Tide ◽  
Spring Tide ◽  
River Estuary ◽  
High Water ◽  
Empirical Models ◽  
Length Scale ◽  
Salt Intrusion ◽  
Salinity Data ◽  
Comparative Results

Abstract. Intensive measurements of salt intrusion in the Sumjin River estuary were taken at high and low waters during both spring and neap tides in each season from August 2004 to April 2007. The estuary demonstrated partially- and well-mixed characteristics during the spring tide and stratified condition during the neap tide. The salt intrusion at high water varied from about 13.39 km in summer 2005 to 25.62 km in autumn 2006. The salt intrusion depended primarily on the freshwater discharges rather than those of spring-neap tidal oscillations. Analysis of three years of observed salinity data indicated that the salt intrusion length scale in the Sumjin River estuary was proportional to the river discharge to the −1/5 power. Five empirical models were applied to the Sumjin River estuary to explore the most suitable as an easy-to-use tool for prediction of the salt intrusion length as functions of the geometry, river discharge and tide. Comparative results showed that the Nguyen and Savenije (2006) model developed under both partially- and well-mixed estuaries yielded the most satisfactory results of all the models studied for computing the salt intrusion length in the Sumjin River estuary. Our study suggests that the model can generate reasonable results for stratified conditions also.

scholarly journals FIELD MEASUREMENTS OF BEDFORMS IN A RIP CHANNEL ON A MACRO-TIDAL BEACH

2012 ◽  
Vol 1 (33) ◽  
pp. 93
Author(s):  
Antony Thorpe ◽  
Jon Miles ◽  
Gerd Masselink ◽  
Paul Russell ◽  
Tim Scott ◽  
...  
Keyword(s):  
Sandy Beach ◽  
High Tide ◽  
Field Measurements ◽  
Rip Current ◽  
Peak Period ◽  
Migration Rates ◽  
Sand Ripple ◽  
Current Maximum ◽  
Offshore Flow ◽  
And Migration

A Sand Ripple Profiler (SRP) was deployed in a rip channel on a dissipative sandy beach to measure bedform height (∆), length (λ) and migration rate (Mr¬) throughout a macro-tidal cycle with an offshore significant wave height of 0.7 m and peak period of 10 s. At lower tidal elevations in the strong offshore flow of the rip current (maximum = 0.4 m/s) bedforms (∆ = 0.15 m, λ = 3 m) were found to migrate offshore (Mr = 0.21 m/hr). Outside of active rip current conditions (water depth (h) = >~2.5 m) bedforms were found to be of smaller scale (∆ = 0.09 – 0.12 m, λ = 1 – 1.2 m) migrating onshore at a rate of 0.35 m/hr at mid tide (h = 3.3 m) and 0.03 m/hr at high tide (h = 6.3 m). Onshore migration rates were found to increase with increased wave skewness and velocity variance.

Extreme waves and surges interaction with tides during storms in winter 2013/2014.

2021 ◽  
Author(s):  
Julia Rulent
Keyword(s):  
Tidal Cycle ◽  
Grid Point ◽  
High Tide ◽  
Water Levels ◽  
Extreme Waves ◽  
Near Shore ◽  
The Uk ◽  
The Waves ◽  
Tidal Stage

&lt;p&gt;The interaction between waves, surges and tides is one of the main drivers of coastal total water levels (TWL). &amp;#160;Understanding this interaction is crucial for studying high TWL formation near shore, and to do this it is important to not only evaluate how high the TWL is but also when and where it occurs.&lt;/p&gt;&lt;p&gt;In this study we use a high resolution (1.5 km) three-way coupled (waves-atmosphere-ocean) numerical model developed by the MetOffice (UKC4) to study coastal conditions at the UK coast during the extreme events of winter 2013, which was chosen as case study because of the amount of flooding that occurred in relation to storms and surges during this period.&lt;/p&gt;&lt;p&gt;For each coastal grid point the ten strongest storms of that winter, ranked by the significant wave height (Hs) magnitude, were selected. During these storm periods, the number of hours in which Hs and surges exceeded the 90&lt;sup&gt;th&lt;/sup&gt; percentile of winter 2013 were evaluated considering what tidal stage they occurred on. The same was done for instances where high Hs and surges occurred simultaneously. The aim is to understand if specific areas were predominantly affected by one of the TWL components and how Hs and surges interacted with the tide. What was the spatial distribution of the waves, surges, and tides during winter 2013? Did extreme Hs and Surges occur more often over specific stages of the tidal cycle? Did they occur simultaneously?&amp;#160;&lt;/p&gt;&lt;p&gt;In this study we show that during the winter 2013, Hs and surges above the 90&lt;sup&gt;th&lt;/sup&gt; percentile value did occur simultaneously at all stages of the tidal cycle. They more often occurred together over the rising tide with in average 8.7% and 8.6% of instances found two and three hours before high tide. In 7.7% of cases high wave and surges also concurred at high tide.&lt;/p&gt;

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