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This study models Iceland’s shelf and surrounding ocean waters to quantify shelf distributions, flushing times, offshore exports (beyond the 400-m isobath), and alongshelf transports of Iceland’s riverine freshwater. Analysis of the 2019 period divides the shelf into four quadrants and follows river waters delivered to each quadrant with tracked freshwater tracers that decay over time in open-ocean waters. Tracked freshwater thicknesses are large in the southwest quadrant and near major rivers in other areas. Freshwater is present around the entire shelf, but is less prevalent in the southeast quadrant. Many river waters can reach halfway around Iceland before being exported offshore; diminishing amounts can almost entirely circumnavigate Iceland. Annual average freshwater flushing times have an approximately seasonal scale at around 3 and 4 months for eastern and western river waters, respectively. Annual average freshwater exports are larger from northern shelf quadrants than southern ones. Average alongshelf freshwater transports are downshelf. Alongshelf connectivity is strong between most quadrants and moderate between the eastern quadrants. Regressions show how export and downshelf transport increase during upwelling-favorable and downwelling-favorable winds, respectively. Results indicate the Icelandic Coastal Current has robust buoyancy signatures and connected currents in western Iceland, and has generally weaker buoyancy and less-pronounced connected flows on the eastern side. 

This dataset contains the supporting data for figures in “Icelandic Riverine Freshwater Distribution, Offshore Export, and Alongshelf Connectivity,” a manuscript for Estuarine, Coastal and Shelf Science by Michael M. Whitney (affiliated with the University of Connecticut). This study simulates Iceland’s shelf and open-ocean waters to investigate riverine freshwater distributions and transports. Tracers are applied to determine flushing times and quantify exports to the open ocean relative to downshelf transports. Results have broader relevance to Iceland’s coastal ecosystems and transports on other continental shelves. The dataset includes MATLAB data files that contain all the output data presented in the corresponding figures within the manuscript. Details about variables and units are described within the figure captions and manuscript text. Modified model code, settings, and input files are included for the Regional Ocean Model System (ROMS) application. The FORTRAN code files have the modifications for tracers that allow for decay in deep waters. The manuscript contains complete descriptions of methods, analysis, and interpretation. List of MATLAB data files: Figure01_data.mat Figure02_data.mat Figure03_data.mat Figure04_data.mat Figure05_data.mat Figure06_data.mat Figure07_data.mat Figure08_data.mat List of modified ROMS code files: def_info.F mod_scalars.F read_phypar.F step3d_t.F wrt_info.F ana_passive.h ana_psource.h List of ROMS settings and input files: iceland.h roms.in boundary2km_lonlatgrid.nc rivers2km_with_additional_rivers_lonlatgrid.nc grid_iceland2km_lonlatgrid.nc iceland2km_lonlatgrid_tideforcing_M2_NA_phase010119.nc initial2km_lonlatgrid_yearend_dyes.nc windforcing2km_lonlatgrid.nc 

This dataset is associated with a manuscript on river plumes and idealized coastal corners with first author Michael M. Whitney. The dataset includes source code, compilation files, and routines to generate input files for the Regional Ocean Modeling System (ROMS) runs used in this study. ROMS output files in NetCDF format are generated by executing the compiled ROMS code with the input files. The dataset also includes MATLAB routines and datafiles for the analysis of model results and generation of figures in the manuscript. The following zip files are included: ROMS_v783_Yan_code.zip [ROMS source code branch used in this study] coastalcorner_ROMS_compilation.zip [files to compile ROMS source code and run-specific Fortran-90 built code] coastalcorner_ROMS_input_generate_MATLAB.zip [ROMS ASCII input file and MATLAB routines to generate ROMS NetCDF input files for runs] coastalcorner_MATLAB_output_analysis.zip [MATLAB data files with selected ROMS output fields and custom analysis routines and datafiles in MATLAB formats used in this study] coastalcorner_MATLAB_figures.zip [custom MATLAB routine for manuscript figure generation and MATLAB data files with all data fields included in figures] coastalcorner_tif_figures.zip [TIF image files of each figure in manuscript] 

This dataset contains the supporting data for figures in “Separation of the Icelandic Coastal Current from the Reykjanes Peninsula,” a scientific article in Estuarine, Coastal and Shelf Science by Michael M. Whitney (affiliated with the University of Connecticut). The main objective of this study is describing and diagnosing Icelandic Coastal Current separation from the southwest tip of the Reykjanes Peninsula and the subsequent offshore excursion. Particular attention is paid to the interplay of coastal curvature, bathymetry, and winds. Motivated by satellite observations and prior research, realistic high-resolution (eddy-resolving) numerical simulations are conducted and analyzed. Sensitivity model runs for the study area are compared to isolate bathymetric and wind influences. Results have broader relevance to offshore transport and exchange on continental shelves. The dataset is composed of MATLAB data files, which are named FigureXX_data.mat. These files contain all data presented in the corresponding figures within the journal article. Details about variables and units are described within the figure captions and text of the article. The article contains complete descriptions of methods, analysis, and interpretation. List of MATLAB data files: Figure01_data.mat Figure02_data.mat Figure03_data.mat Figure04_data.mat Figure05_data.mat Figure06_data.mat Figure07_data.mat Figure08_data.mat Figure09_data.mat Figure10_data.mat Figure11_data.mat Figure12_data.mat 

The Connecticut River plume interacts with the strong tidal currents of the ambient receiving waters in eastern Long Island Sound. The plume formed during ambient flood tides is studied as an example of tidal river plumes entering into energetic ambient tidal environments in estuaries or continental shelves. Conservative passive freshwater tracers within a high-resolution nested hydrodynamic model are applied to determine how source waters from different parts of the tidal cycle contribute to plume composition and interact with bounding plume fronts. The connection to source waters can be cut off only under low-discharge conditions, when tides reverse surface flow through the mouth after max ambient flood. Upstream plume extent is limited because ambient tidal currents arrest the opposing plume propagation, as the tidal internal Froude number exceeds one. The downstream extent of the tidal plume always is within 20 km from the mouth, which is less than twice the ambient tidal excursion. Freshwaters in the river during the preceding ambient ebb are the oldest found in the new flood plume. Connectivity with source waters and plume fronts exhibits a strong upstream-to-downstream asymmetry. The arrested upstream front has high connectivity, as all freshwaters exiting the mouth immediately interact with this boundary. The downstream plume front has the lowest overall connectivity, as interaction is limited to the oldest waters since younger interior waters do not overtake this front. The offshore front and inshore boundary exhibit a downstream progression from younger to older waters and decreasing overall connectivity with source waters. Plume-averaged freshwater tracer concentrations and variances both exhibit an initial growth period followed by a longer decay period for the remainder of the tidal period. The plume-averaged tracer variance is increased by mouth inputs, decreased by entrainment, and destroyed by internal mixing. Peak entrainment velocities for younger waters are higher than values for older waters, indicating stronger entrainment closer to the mouth. Entrainment and mixing time scales (1–4 h at max ambient flood) are both shorter than half a tidal period, indicating entrainment and mixing are vigorous enough to rapidly diminish tracer variance within the plume. 

Abstract The mixing of river plumes into the coastal ocean influences the fate of river-borne tracers over the inner-shelf, though the relative importance of mixing mechanisms under different environmental conditions is not fully understood. In particular, the contribution to plume mixing from bottom generated shear stresses, referred to as tidal mixing, is rarely considered important relative to frontal and stratified shear (interfacial) mixing in surface advected plumes. The effect of different mixing mechanisms is investigated numerically on an idealized, tidally pulsed river plume with varying river discharge and tidal amplitudes. Frontal, interfacial, and tidal mixing are quantified via a mixing energy budget to compare the relative importance of each to the overall buoyancy flux over one tide. Results indicate that tidal mixing can dominate the energy budget when the tidal mixing power exceeds that of the input buoyancy flux. This occurs when the non-dimensional number, Ri E (the estuarine Richardson number divided by the mouth Rossby number), is generally less than 1. Tidal mixing accounts for between 60% and 90% of the net mixing when Ri E < 1, with the largest contributions during large tides and low discharge. Interfacial mixing varies from 10% to 90% of total mixing and dominates the budget for high discharge events with relatively weaker tides ( Ri E > 1). Frontal mixing is always less than 10% of total mixing and never dominates the budget. This work is the first to show tidal mixing as an important mixing mechanism in surface advected river plumes.