Joseph W. Long

University of North Carolina at Wilmington | UNCW · Department of Physics and Physical Oceanography

A yearlong wind and wave dataset derived from a cost-effective GPS wave buoy (Spotter) is compared to waves obtained from an accelerometer wave buoy (Datawell) and winds obtained from a collocated meteorological buoy. Overall, there was a strong correlation in bulk wave parameters obtained from the Spotter buoy and the Datawell buoy (RMSE of 0.06 m...

Over short periods of time, extreme storms can significantly alter barrier island morphology, increasing the vulnerability of coastal habitats and communities relative to future storms. These impacts are complex and the result of interactions between oceanographic conditions and the geomorphic, geological, and ecological characteristics of the isla...

Wave wash-over poses a significant threat to sea turtle nests, with sustained exposure to waves potentially resulting in embryonic mortality and altered hatchling locomotor function, size, and sex ratios. Identifying where and under what conditions wave exposure becomes a problem, and deciding what action(s) to take (if any), is a common issue for...

Hurricane Isaias struck the Cape Fear Region of North Carolina around 23:00 EDT on 3 August 2020, making landfall at Ocean Isle Beach as a Category 1 storm with peak wind speeds of 80 mph. An array of nearshore Sofar Spotter wave buoys captured the wave field at two beaches off the coasts of Bald Head Island (south-facing and east-facing beaches) a...

The prediction of wave runup, as well as its components, time-averaged setup and the time-varying swash, is a key element of coastal storm hazard assessments, as wave runup controls the transitions between morphodynamic response types such as dune erosion and overwash, and the potential for flooding by wave overtopping. While theoretically able to...

Resolving surf-zone bathymetry from high-resolution imagery typically involves measuring wave speeds and performing a physics-based inversion process using linear wave theory, or data assimilation techniques which combine multiple remotely sensed parameters with numerical models. In this work, we explored what types of coastal imagery can be best u...

Plain Language Summary Barrier islands protect mainland coastal communities during storms. In the future, the effects of storms and sea level rise (SLR) threaten barrier islands with increased inundation and loss of land. Barrier islands can keep pace with SLR by moving sand across the island during storm events to maintain height and width. Howeve...

An interdisciplinary project team was convened to develop a modeling framework that simulates the potential impacts of storms and sea level-rise to habitat availability at Breton Island, Louisiana, for existing conditions and potential future restoration designs. The model framework was iteratively developed through evaluation of model results at m...

Dune erosion is an important aspect to consider when assessing coastal flood risk, as dune elevation loss makes the protected areas more susceptible to flooding. However, most advanced dune erosion numerical models are computationally expensive, which hinders their application in early‐warning systems. Based on a combination of probabilistic and pr...

Web cameras are transforming coastal environmental monitoring. Improvements in camera technology and image processing capabilities, paired with decreases in cost, enable widespread use of camera systems by researchers, managers and first responders for a growing range of environmental monitoring applications. Applications are related to transportat...

The inundation of foreshore and backshore coastal environments caused by wave runup or groundwater intrusion can be extremely detrimental for beach-dwelling organisms. For beach-nesting species, whose eggs require sufficient gas exchange with the surrounding environment for proper embryonic development, inundation for prolonged periods can result i...

Oceanographic variables such as mean sea level, tides, storm surges, and waves are drivers of erosion, and they act on different time scales ranging from hours (associated with weather) to seasonal and decadal variations and trends (associated with climate). Storm erosion of dunes, which often protect coastal communities and built infrastructure fr...

Coral reefs can influence hydrodynamics and morphodynamics by dissipating and refracting incident wave energy, modifying circulation patterns, and altering sediment transport pathways. In this study, the sediment and hydrodynamic response of a senile (dead) barrier reef (Crocker Reef, located in the upper portion of the Florida Reef Tract) to storm...

Sea level rise (SLR) has the potential to exacerbate the impacts of extreme storm events on the coastal landscape. This study examines the coupled interactions of SLR on storm-driven hydrodynamics and barrier island morphology. A numerical model is used to simulate the hydrodynamic and morphodynamic impacts of two Gulf of Mexico hurricanes under pr...

Methods for investigating the vulnerability of existing or proposed coastal features to storm impacts often rely on simplified parametric models or one-dimensional process-based modeling studies that focus on changes to a profile across a dune or barrier island. These simple studies tend to neglect the impacts to curvilinear or alongshore varying i...

Variations in bed friction due to land cover type have the potential to influence morphologic change during storm events; the importance of these variations can be studied through numerical simulation and experimentation at locations with sufficient observational data to initialize realistic scenarios, evaluate model accuracy and guide interpretati...

Models of dune erosion depend on a set of assumptions that dictate the predicted evolution of dunes throughout the duration of a storm. Lidar observations made before and after Hurricane Sandy at over 800 profiles with diverse dune elevations, widths, and volumes are used to quantify specific dune erosion model parameters including the dune face sl...

We assess erosion and flooding risk in the northern Gulf of Mexico by identifying interdependencies among oceanographic drivers and probabilistically modeling the resulting potential for coastal change. Wave and water level observations are used to determine relationships between six hydrodynamic parameters that influence total water level and ther...

Surface wave transformation and the resulting nearshore circulation along a section of coast with strong alongshore bathymetric gradients outside the surf zone are modeled for a consecutive 4 week time period. The modeled hydrodynamics are compared to in situ measurements of waves and currents collected during the Nearshore Canyon Experiment and in...

Despite their utility for prediction of coastal behavior and for coastal management, littoral sediment budgets are difficult to quantify over large regions of coastline and over short time scales. In this study, bathymetric change analysis shows differences in the magnitude and spatial location of erosion and accretion over three years; more net ac...

Large geomorphic changes to barrier islands may occur during inundation, when storm surge exceeds island elevation. Inundation occurs episodically and under energetic conditions that make quantitative observations difficult. We measured water levels on both sides of a barrier island in the northern Chandeleur Islands during inundation by Hurricane...

Extreme storms drive change in coastal areas, including destruction of dune systems that protect coastal populations. Data from four extreme storms impacting four geomorphically-diverse barrier islands are used to quantify dune elevation change. This change is compared to storm characteristics to identify variability in dune response, improve under...

Low-lying barrier islands are ubiquitous features of the world's coastlines, and the processes responsible for their formation, maintenance, and destruction are related to the evolution of smaller, superimposed features including sand dunes, beach berms, and sandbars. The barrier island and its superimposed features interact with oceanographic forc...

The demography, spatial distribution, and movement patterns of leopard sharks (Triakis semifasciata) aggregating near the head of a submarine canyon in La Jolla, California, USA, were investigated to resolve the causal explanations for this and similar shark aggregations. All sharks sampled from the aggregation site (n = 140) were sexually mature a...

U.S. Geological Survey (USGS) scientists have provided a model-based assessment of transport and deposition of residual Deepwater Horizon oil along the shoreline within the northern Gulf of Mexico in the form of mixtures of sand and weathered oil, known as surface residual balls (SRBs). The results of this USGS research, in combination with results...

A shoreline change model incorporating both long- and short-term evolution is integrated into a data assimilation framework that uses sparse observations to generate an updated forecast of shoreline position and to estimate unobserved geophysical variables and model parameters. Application of the assimilation algorithm provides quantitative statist...

After the Deepwater Horizon explosion and oil spill, Louisiana received permission to build a sand berm parallel to and offshore of the ~30-km-long Chandeleur Islands to capture floating oil and keep it from reaching mainland marshes. The berm was built with dredged sand to a height of approximately 2 m above mean sea level and within 100 m of the...

A modeling system that considers both long- and short-term process-driven shoreline change is presented. The modeling system is integrated into a data assimilation framework that uses sparse observations of shoreline change to correct a model forecast and to determine unobserved model variables and free parameters. Application of the assimilation a...

Erodible coastlines can evolve dramatically due to single storm events. These events typically cause rapid shoreline erosion and/or barrier island migration. Evolution over longer time periods under moderate conditions can act to restore storm-caused erosion or to contribute further to erosional processes. In the case of barrier islands, a natural...

Discrete, large scale, meteorological events such as hurricanes can cause wide-spread destruction of coastal islands, habitats, and infrastructure. The effects can vary significantly along the coast depending on the configuration of the coastline, variable dune elevations, changes in geomorphology (sandy beach vs. marshland), and alongshore variati...

Copyrighted by American Geophysical Union. The dynamics of vorticity motions forced by wave groups incident on an alongshore-uniform barred beach are analyzed. For both normally and obliquely incident wave groups, the potential vorticity and enstrophy equations reveal that the temporal variability of wave group–forced vortices is directly linked to...

Month-long simulations of the nearshore circulation field along a complex coastline are presented. A wave-circulation model is developed that accounts for variations in the tides, offshore wave conditions, and changes in the nearshore bathymetry in order to analyze the transient rip currents that develop at this site due to refraction patterns of g...

Hydrodynamic models are used as a diagnostic tool to understand the temporal variability of shallow-water processes that are difficult to completely resolve with traditional field measurements. For all simulations, modeled quantities are qualitatively or quantitatively compared with available measurements to gain confidence in conclusions derived f...

A series of idealized model simulations are performed to investigate the dynamics of depth-integrated vortical motions generated by spatially and temporally varying wave groups. In particular, the effect that subsequent wave groups of varying magnitude have on an existing circulation cell is examined. The primary diagnostic tool used in this study...

Dynamics in the nearshore region with time scales that reside in the infragravity band continue to be identified and examined. Consequently, an increase in possible mechanisms that drive these motions inherently make the individual forcing and response more difficult to distinguish and interpret (i.e. edge waves, shear waves [e.g. Oltman-Shay et al...

Copyrighted by American Geophysical Union. The rip current field resulting from the transformation of surface gravity waves over offshore submarine canyons is studied. Employing a wave transformation model and a wave-induced circulation model over observed bathymetry we find that wave height variations associated with undulations in the canyon cont...

The details of a large-scale laboratory experiment to study the turbulence generated by waves breaking on a fixed barred beach are presented. The data set includes comprehensive measurements of free surface displacement and fluid velocity for one random and one regular wave case. Observations of the time-averaged turbulent kinetic energy per unit m...

The details of a large-scale laboratory experiment to study the turbulence generated by waves breaking on a fixed barred beach are presented. The data set includes comprehensive measurements of free surface displacement and fluid velocity for one random and one regular wave case. Observations of the time-averaged turbulent kinetic energy per unit m...

Evaluation of data collected during the Nearshore Canyon Experiment, has shown that our time-dependent circulation model (OK-Model; Özkan-Haller and Kirby, JGR, 1999), forced using radiation stress gradients derived from spectral wave models, can predict the spatial location of large offshore directed flows (rip currents). The locations of these tr...