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Water and sediment fluxes in Barataria Bay inferred from observations and modeling. Solid white arrows denote geographical regions. Solid blue arrows and hollow white arrows represent water fluxes and sediment fluxes, respectively. Legends in green indicate inflow sites (GIWW, Gulf Intracoastal Waterway). The site of the proposed future mid-Barataria sediment diversion is represented by a green star symbol. Mean water discharge at Naomi from 2006 to 2019 was used to infer mean discharge for both Naomi and West Pointe à
Source publication
Estuarine and coastal geomorphology, biogeochemistry, water quality, and coastal food webs in river-dominated shelves of the Gulf of Mexico (GoM) are modulated by transport processes associated with river inputs, winds, waves, tides, and deepocean/continental shelf interactions. For instance, transport processes control the fate of river-borne sedi...
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Context 1
... striking example of the limited knowledge associated with both field measurements and modeling is the net exchange of water and sediments (as well as carbon and nutrients) through tidal inlets. For example, at the main inlet of Barataria Bay (Fig. 3), there are large uncertainties in the estimates of net estuarine outflow (i.e., 127-380 m 3 /s), and the magnitude and the direction of sediment flux (import or export) ( Payandeh et al. 2021;Mariotti et al. ...
Context 2
... suggest that large sediment diversions can affect estuarine flushing > 60 km from diversion structure and therefore could have significant effects on surface oil transport, albeit with important ecological tradeoffs due to estuarine freshening. For example, a hypothetical constant discharge of 850 m 3 /s from a Mid-Barataria sediment diversion (Fig. 3) for 3 months is predicted to greatly reduce estuarine residence times, especially in the lower reaches of Barataria Bay, with the average salinity exhibiting a ~ 12 point reduction near the Barataria Pass compared to a scenario with no diversion (Cui 2018). Furthermore, the area experiencing decreased salinities is larger along the ...
Citations
... Tides are the main parameter generating currents. However, in nearshore areas, waves will also induce high velocity due to breaking mechanisms that transport sediment [4], nutrients [5] or fish larvae [6]. Hence, monitoring and understanding these processes are critical for effective coastal management, conservation, and hazard mitigation. ...
Nearshore hydrodynamics, such as water level fluctuations, field observations play a crucial role in understanding and monitoring the dynamics of the coastal region. The observed parameters provide insight into oceanographic processes, climate change impacts, and the behavior of marine ecosystems that could be valuable for coastal management and infrastructure development planning. Most of the available hydrodynamic loggers are provided by companies with relatively high prices. Due to limited budgets, many areas including Indonesia waters, have limited hydrodynamic observation data. In this paper, we presented a prototype of a simple (DIY-Do It Yourself) and low-cost water level logger with a microcomputer that could be applied in coastal regions. The system consists of a pressure-based sensor to detect water level fluctuations, a temperature sensor, a single-board microcomputer and data logger, and a power supply with different sampling frequencies for various coastal applications. The result showed the ability of the microcomputer system to measure high-resolution water levels and temperatures applicable for non-directional waves, tides and non-tides observations, and ecological monitoring. The microcomputer’s low power consumption makes it suitable for long-term coastal observations, even in remote or battery-powered applications. The body of the logger is designed from PVC-nylon with sensors made from waterproof and corrosion-free materials to ensure its applicability for coastal monitoring. Moreover, the flexibility of the microcomputer system allows for customization and adaptation to specific research requirements at relatively affordable prices.
... Physical and biogeochemical models for depicting climate-driven changes in environmental features that are often used to force higher trophic level models continue to increase in skill and spatial resolution (Bonan & Doney 2018, Swearer et al. 2019, Hewitt et al. 2020, Hood et al. 2021, Justic et al. 2022). This increased temporal and spatial accuracy and resolution of temperature, as well as other abiotic variables, provides an opportunity to better formulate how these variables impact the bioenergetics processes of individuals. ...
Climate change has rapidly altered marine ecosystems and is expected to continue to push systems and species beyond historical baselines into novel conditions. Projecting responses of organisms and populations to these novel environmental conditions often requires extrapolations beyond observed conditions, challenging the predictive limits of statistical modeling capabilities. Bioenergetics modeling provides the mechanistic basis for projecting climate change effects on marine living resources in novel conditions, has a long history of development, and has been applied widely to fish and other taxa. We provide our perspective on four opportunities that will advance the ability of bioenergetics-based models to depict changes in the productivity and distribution of fishes and other marine organisms, leading to more robust projections of climate impacts. These are (1) improved depiction of bioenergetics processes to derive realistic individual-level response(s) to complex changes in environmental conditions, (2) innovations in scaling individual-level bioenergetics to projecting responses at the population and food web levels, (3) more realistic coupling between spatial dynamics and bioenergetics to better represent the local- to regional-scale differences in the effects of climate change on the spatial distributions of organisms, and (4) innovations in model validation to ensure that the next generation of bioenergetics-based models can be used with known and sufficient confidence. Our focus on specific opportunities will enable critical advancement of bioenergetics modeling and position the modeling community to make more accurate and robust projections of the effects of climate change on individuals, populations, food webs, and ecosystems.
... Our findings have revealed that when considering reciprocal hydrological lateral C and N flows, single ecosystems can function as both sources and sinks within the meta-ecosystem framework (Figure 7) (Gravel et al., 2010). In the meta-ecosystem framework, the transfer and modification of resource flows driven by tidal movements, along with dispersal-based connections between these ecosystems, result in even larger-scale exchanges between ecosystems (Justić et al., 2022). Furthermore, these dynamics can have feedback effects on dispersal-based meta-ecosystems and resource-flow-based meta-ecosystems and underscore the significance of balancing the C/N budget within coastal 11 wetlands in the context of the terrestrial-aquatic continuum (Limberger et al., 2017). ...
The dynamics of hydrological lateral nutrient fluxes contribute to our understanding of ecological functions related to energy, materials, and organism flows across various spatiotemporal scales. To explore the connectivity between multiple spatial flow processes, we conducted a one-year field measurement to assess lateral hydrologic carbon (C) and nitrogen (N) fluxes over the continental shelf in the Yangtze estuary. We observed a significant correlation between the differences in remote sensing-based estimates of gross primary production (GPP) (∆GPPMODIS) and the differences in eddy covariance (EC) tower-based GPP (∆GPPEC) at both high-elevation and low-elevation sites. Over the course of a year, our predicted daily maximum tidal elevation (TE) closely matched the observed values in the creek, which facilitated the development of theoretical models to simulate biogeochemical cycling processes and aquatic ecosystem functions. Our findings indicate that the studied saltmarsh acts as a net exporter of dissolved total C (DTC) while serving as a net sink for dissolved total N (DTN). Furthermore, there is a significant correlation in the total dissolved stoichiometry of the C/N ratio between imports and exports. These findings highlight the importance of integrating ecological stoichiometric principles to gain a deeper understanding of the complex relationships between physical, chemical, and biological processes, particularly within the context of the meta-ecosystem framework. Additionally, when considering reciprocal hydrological lateral C and N flows, single ecosystem can function both as sources and sinks within the meta-ecosystem framework.
... As with any internal or external source of hydrological C, various sources mix into a common pool of lateral fluxes that resides in the water column and saltmarsh until they are either deposited on the surface of tidal flats or exported to the sea (Hopkinson et al., 2018). The greatest challenge related to the outwelling hypothesis has always been to understand how hydrological organic matter in a given salt marsh could represent the lateral fluxes carried by tidal activities and whether it is likely to be transported to adjacent waters during astronomical tides (Justić et al., 2022). Obviously, uncertainties in such a dynamic environment must be better constrained and carefully estimated at multiple temporal scales, especially one-to-two weeks, including monthly tidal cycles. ...
... As with any internal or external source of hydrological C, various sources mix into a common pool of lateral fluxes that resides in the water column and saltmarsh until they are either deposited on the surface of tidal flats or exported to the sea (Hopkinson et al., 2018). The greatest challenge related to the outwelling hypothesis has always been to understand how hydrological organic matter in a given salt marsh could represent the lateral fluxes carried by tidal activities and whether it is likely to be transported to adjacent waters during astronomical tides (Justić et al., 2022). Obviously, uncertainties in such a dynamic environment must be better constrained and carefully estimated at multiple temporal scales, especially one-to-two weeks, including monthly tidal cycles. ...
... LCE can stimulate productivity in the GoM in the winter via mixed layer deepening, which brings nutrient-richer water into the mixed layer [27]. The LC, LCE, and LCFE influence processes on the continental shelf and slope in the northern GoM in all seasons [28] and generate cross-isobath transports to advect the Mississippi and Atchafalaya Rivers' water and materials offshore [29][30][31]. ...
This study characterizes the spatial patterns of the overall and monthly trends in sea surface temperature (SST) and chlorophyll-a (Chl-a) of the Gulf of Mexico (GoM) to investigate the seasonal variations in oceanic climate trends. We also investigate the trends in mesoscale eddies using three parameters to identify ocean-eddy-related energetic features in their area, strength, and intensity. Multidecadal remote-sensing-based observations of monthly SST, Chl-a, and sea surface height are used to detect trends at both basin and grid scales. Prominent warming trends are found in most regions of the GoM in all months, with the largest trends in the northern GoM. Winter cooling trends are also detected along the Texas and Florida coast. The overall summer warming trend (~0.22 °C/decade) is larger than the winter trend (~0.05 °C/decade), suggesting seasonal variations of increase in SST with warming. Chl-a trends and variations are confined on the continental shelf and slope in the northern GoM. The largest increase trends are found near the Mississippi River Delta. No obvious Chl-a trend is detected in the deepwater of the GoM, consistent with previous studies. Small but significant changes are found in eddy characteristics, indicating the eddy activities might be slowly affected by climate change in the GoM. The detailed monthly trends at per-grid scale are valuable for regional resource management, environmental protection, and policy making in the GoM.
... It represents 80% of the annual freshwater input to the Gulf of Mexico, 90% of the total nitrogen load (mainly of agricultural origin) and 87% of the phosphorous load to the basin (Dunn, 1996). River discharge does not only influence the shelf region (e.g., Greer et al., 2018), but also interacts with the circulation further offshore (see Justic et al., 2021, for a review). Schiller et al. (2011) have shown that offshore transport associated with the interaction of the river plume and the mesoscale circulations happens frequently and depends on the mesoscale variability and on topographic and wind effects. ...
The potential predictability of fields at the ocean surface in the northern Gulf of Mexico (GoM) is investigated through five ensembles of regional ocean simulations between 2014 and 2016. The ensembles explore two horizontal resolutions and different representations of the riverine inflow, and focus on the interactions between the Loop Current system (LCS) and the riverine system. The potential predictability of the surface fields is high when simulated by an ocean‐only model forced by appropriate atmospheric forcing and boundary conditions, and the ensembles simulate similar LCS behavior up to 5 months. The ensemble spread provides a mean to quantify the potential predictability. The ensembles confirm that LCS‐riverine interactions are modulated by the LC mesoscale variability. The relationship is two‐ways, with the LCS being influenced by—And not only influencing—The freshwater plume. Whenever the freshwater flux is strong, the northward extension of the LCS is constrained by the intensified salinity fronts. This influence is slightly stronger if the riverine inflow is simulated in an active fashion with a meridional velocity component proportional to the flux. Sea surface temperature (SST) and salinity (SSS) predictability have opposite seasonality in their signal, with the SST (SSS) being more predictable in summer (winter). Partially resolving submesoscale instabilities and improving the realism of the riverine fluxes’ representation causes the spread to increase, especially in SST. When increasing resolution, the spread increases also for surface vorticity due to feedbacks between the mesoscale and submesoscale circulations. The intraseasonal and interannual signal in vorticity is however similar among ensembles.
... In the GoM, for example, mesoscale structures and rivering inputs have been shown to jointly contribute to the juxstaposition of water masses with different densities and therefore to the development of frontal and baroclinic instabilities. The end result is the formation of submesoscale lateral convergence zones (Luo et al., 2016;Barkan et al., 2017a,b) where fresh water, nutrients, and pollutants accumulate (Huntley et al., 2015;Choi et al., 2017;Bracco et al., 2019;Justic et al., 2021). ...
The Gulf of Mexico is a very productive and economically important system where riverine runoff acts as a linkage between the continental shelf and the open ocean, providing nutrients in addition to freshwater. This work investigates the three-dimensional transport and pathway structure of this river runoff offshore the continental shelf using ensembles of numerical simulations with different configurations regarding grid resolution (mesoscale resolving and submesoscale permitting) and river setup using suites of 5-months long integrations covering nearly 3 years. The riverine forcing is applied only at the surface over an area around the river mouth, a strategy often adopted in numerical studies, or as a meridional flux with a vertical extension. The simulated flow captures the southward offshore transport of river runoff driven by its interaction with the largest mesoscale circulations in the basin, the Loop Current and Loop Current eddies. This pathway is strong and well-document during summer but also active and relevant in winter, despite a less obvious surface signature. The most intense transport occurs primarily at the peripheries of the Loop Current and the detached eddies, and the freshwater is subducted as deep as 600 m around the mesoscale anticyclonic eddies. Submesoscale motions strengthen slightly the spread of freshwater plumes in summer but their contribution is negligible, if not negative, in winter. Differences in the freshwater distribution and transport volume among runs are small and generally less than 10% among ensembles, with overall slightly higher volume of freshwater transported off-shore and at depth in submesoscale permitting runs that include a velocity flux in their riverine input representation.
The numerical model of wave field distribution using time dependent of wave combination from refraction-diffraction equation on a gentle slope was carried out in Modeling Laboratory of Marine and Fisheries Faculty of Syiah Kuala University. The research of numerical modeling was conducted to understand how the impact of the presence of coastal structures on the coast toward the wave dynamic approach. In the theory, the greater of wave angle, the greater of wave height distribution will be behind the breakwater, thus allowing large sediment transport to make changes to the coast. Therefore, this research is important because the knowledge of the relationship between waves and coastal structure is still limited while the dynamics of the coast have a distinctive significance in the regions. The study aims to determine the wave phenomena that interact with the structure of the coastal building so that the results of this study can be used and utilized as substantial study for future coastal planning. The method used in this study is the application of wave equations that may be solved by numerical model. The model results show that the greater the angle of incidence of waves on the southwest coast, the greater the wave height produced when it hits coastal structures. However, this characteristic does not occur in the west coast region. This is caused by the topographic nature of coastal areas and different coastal characteristics.
