Data Supporting the Figures in Freshwater composition and connectivity of the Connecticut River plume during ambient flood tides

Supporting data for figures in Freshwater composition and connectivity of the Connecticut River plume during ambient flood tides by Michael M. Whitney, Yan Jia, Kelly L. Cole, Daniel G. MacDonald, Kimberly D. Huguenard. The scientific journal article is published in Frontiers in Marine Science (2021). The main objectives of this study on the Connecticut River plume formed during ambient flood tidal conditions are: 1) determining the contributions of river source waters from different parts of the tidal cycle and 2) quantifying the degree and spatial distribution of connectivity of these source waters with the bounding plume fronts. A high-resolution numerical modeling approach is taken. Data are from the Regional Ocean Modeling System (ROMS) results for the study area. Files are in MATLAB data format and are named FigureXX_data.mat. Variable names and units correspond to graphed data of each figure in the journal article

Supporting Data for Freshwater composition and connectivity of the Connecticut River plume during ambient flood tides

Supporting data for figures in Freshwater composition and connectivity of the Connecticut River plume during ambient flood tides by Michael M. Whitney, Yan Jia, Kelly L. Cole, Daniel G. MacDonald, Kimberly D. Huguenard. The scientific journal article is published in Frontiers in Marine Science (2021). The main objectives of this study on the Connecticut River plume formed during ambient flood tidal conditions are: 1) determining the contributions of river source waters from different parts of the tidal cycle and 2) quantifying the degree and spatial distribution of connectivity of these source waters with the bounding plume fronts. A high-resolution numerical modeling approach is taken. Data are from the Regional Ocean Modeling System (ROMS) results for the study area. Files are in MATLAB data format and are named FigureXX_data.mat. Variable names and units correspond to graphed data of each figure in the journal article

An estuarine box model of freshwater delivery to the coastal ocean for use in climate models

Present day climate models employ a coarse horizontal grid that is unable to fully resolve estuaries or continental shelves. The importation of fresh water from rivers is critical to the state of deep ocean stratification, but currently the processing of that fresh water as it passes from the river through the estuary and adjacent shelf is not represented in the coastal boundary conditions of climate models. An efficient way to represent this input of fresh water to the deep ocean would be to treat the estuary and shelf domains as two coupled box models with river water input to the estuarine box and mixed fresh water and coastal water output from the shelf box to the deep ocean.We develop and test the estuary box model here. The potential energy anomaly ϕ is found from the five competing rates of change induced by freshwater inflow, mixed water outflow to the shelf, tidal mixing, surface heat flux, and wind-induced mixing. When application of the box model is made to the Delaware estuary, the wind mixing term contributes little. A 15-year time series of ϕ compares surprisingly well with the calculations of a three-dimensional numerical model applied to the Delaware estuary. The results encourage the future development of a shelf box model as the next step in constructing needed boundary conditions for input of fresh water to the deep ocean component of coupled climate models

The physics of blue crab larval recruitment in Delaware Bay: A model study

Recent studies have shown that the tidal-, wind- and buoyancy-driven surface currents govern the transport of blue crab (Callinectes sapidus) larvae within the coastal ocean and estuaries. Here, we develop a model of larval transport within Delaware Bay and the adjoining coastal ocean using a particle advection scheme coupled to a previously validated physical circulation model which includes realistic tidal forcing, bottom bathymetry, wind stress and river discharge. The coupled model is then used to quantify the effects of several mechanisms on larval transport and recruitment in this region and hindcast actual larval settlement for a four-year period.The model is run for the years 1989–1992 and compared with observations of larval settlement collected in the Broadkill River, a small tributary to Delaware Bay. It is able to reproduce all of the major observed recruitment events in 1990–1992, suggesting that larval recruitment is primarily driven by the physical mechanisms included in the model. Analysis of the modeled particle trajectories and the settlement data reveals that wind stress is the dominant mechanism in the determination of the timing of the settlement events, while horizontal diffusion and mortality determine the magnitude of the events. The model fails to agree with observations in 1989, indicating that small-scale physical events as well as larval behavior not reproduced in the numerical model can be important in larval settlement

The ideal response of a Gulf of Mexico estuary plume to wind forcing: Its connection with salt flux and a Lagrangian view

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95390/1/jgrc11924.pd

Energetics in Delaware Bay: Comparison of two box models with observations

A corrected version of an unstratified box model of potential energy anomaly , initially developed by Garvine and Whitney (2006), and a new two-layer box model that allows for stratified and well-mixed conditions are applied to Delaware Bay. The models are applied for the Garvine and Whitney (2006) 1988-1994 study period and in Spring 2003; however, only model results of potential energy anomaly from the latter period are compared to in situ observations obtained outside the bay mouth. Unstratified model results for the two study periods reveal that the river discharge (Ω1) is the largest potential energy anomaly contributor. This term is closely followed (but with opposite sign) by the coastal current efflux term (Ω2). For the two-layer model the largest contributor is the dense inflow term (Ω6). The wind term (Ω5) is the second largest, followed by the tide (Ω3), river discharge (Ω1) and coastal current terms. In both models the solar heat flux term (Ω4) makes the smallest contribution to ϕ. The available one-month comparison of model results to observations renders statistically insignificant correlation coefficients for both models. We speculate dynamical differences between conditions at the estuary mouth and the instrument location on the nearby shelf contribute to the model-observation mismatch. Other statistics, such as the root mean square error indicate that the unstratified model performs better than the two-layer model for the observation period. The latter model is, however, able to depict the importance of tides and winds in the computation of potential energy anomaly and is able to detect the response of ϕ due to strong wind events. While there is no clear model choice for the Delaware Bay, the unstratified model may be entirely inappropriate for highly stratified estuaries

Wind Effects on Near- and Midfield Mixing in Tidally Pulsed River Plumes

River plumes transport and mix land-based tracers into the ocean. In tidally pulsed river plumes, wind effects have long been considered negligible in modulating interfacial mixing in the energetic nearfield region. This research tests the influence of variable, realistic winds on mixing in the interior plume. A numerical model of the Merrimack River plume-shelf system is utilized, with an application of the salinity variance approach employed to identify spatial and temporal variation in advection, straining, and dissipation (mixing) of vertical salinity variance (stratification). Results indicate that moderate wind stresses (∼0.5 Pa) with a northward component countering the downcoast rotation of the plume are most effective at decreasing stratification in the domain relative to other wind conditions. Northward winds advect plume and ambient shelf stratification offshore, allowing shelf water salinity to increase in the nearshore, which strengthens the density gradient at the plume base. Straining in the plume increases with winds enhancing offshore-directed surface velocities, leading to increased shear at the plume base. Increased straining and larger density gradients at the plume base enhance variance dissipation in the near- and midfield plume, and dissipation remains enhanced if the shelf is clear of residual stratification. The smaller spatial and temporal scales of the Merrimack plume allow the mechanisms to occur at tidal time scales in direct response to instantaneous winds. This is the first study to show tidal time scale wind-induced straining and advection as controlling factors on near- and midfield mixing rates in river plumes under realistic winds