Alfredo Aretxabaleta , PhD
Alfredo's (he/him/his), research mainly focuses in processes controlling water level in coastal environments including tidal effects, storm events, and sea level rise. Another important focus is the investigation of the problems related to sediment transport, especially during storm events, that can affect the redistribution of sediment.
Biography
I have a B.S. degree in Marine Sciences (1998) from the Universidad de Las Palmas de Gran Canaria (ULPGC) and a Ph.D. in Marine Sciences (Physical Oceanography) from UNC Chapel Hill (2005). I worked as a post-doctoral research fellow at the Department of Marine Sciences at UNC Chapel Hill, at the Woods Hole Oceanographic Institution (AOPE), and at the Instituto de Ciencias del Mar - CSIC in Barcelona, Spain. I worked as a scientific programmer contractor at U.S. Geological Survey Woods Hole Coastal and Marine Science Center (WHCMSC) until 2016. Now, I am an oceanographer at the WHCMSC.
Science and Products
Making USGS/NOAA Total Water Level and Coastal Change Forecast data accessible through user-friendly interfaces
The Total Water Level and Coastal Change Forecast delivers 6-day forecasts of hourly water levels and the probability of waves impacting dunes along 5000 km of sandy coasts along the Atlantic and Gulf of Mexico and will soon expand to the Pacific. These forecasts provide needed information to local governments and federal partners and are used by the USGS to place sensors before a storm. The...
Coastal System Change at Fire Island, New York
Fire Island is a 50-km long barrier island along the south shore of Long Island, New York. The island is comprised of seventeen year-round communities; federal, state, and county parks; and supports distinct ecosystems alongside areas of economic and cultural value. In addition to providing resources to its residents, the barrier island also protects the heavily-populated mainland from storm...
Back-barrier and Estuarine - Coastal System Change at Fire Island, New York
Regional-scale modeling forecasts how atmospheric forcing and oceanographic circulation influence estuarine circulation and water levels, sediment transport, and wetland change.
Estuarine Processes, Hazards, and Ecosystems
Estuarine processes, hazards, and ecosystems describes several interdisciplinary projects that aim to quantify and understand estuarine processes through observations and numerical modeling. Both the spatial and temporal scales of these mechanisms are important, and therefore require modern instrumentation and state-of-the-art hydrodynamic models. These projects are led from the U.S....
Coastal Model Applications and Field Measurements
Numerical models are used by scientists, engineers, coastal managers, and the public to understand and predict processes in the coastal ocean. This project supports the development and application of open-source coastal models and has several objectives: 1) improve the code of numerical sediment-transport models by implementing new or improved algorithms; 2) obtain measurements of coastal...
Estuarine Processes Eutrophication
Increased loadings of nutrients to estuaries have altered ecosystem function by encouraging growth of phytoplankton and macroalgae while inducing large swings in dissolved oxygen and threatening the sustainability of seagrass meadows. We are measuring and modeling these processes to understand the future trajectory of estuarine ecosystems.
Estuarine Processes Coastal Hazards
Extreme tides and coastal storms transfer high water levels to estuaries through natural and managed entrances. The size of the transfer depends on the duration of the event and the geomorphology of the estuary. We use observational data and modeling scenarios to understand and spatially map this transfer at our study sites.
Estuarine Processes Model Development
We are developing new routines within the COAWST model framework to represent coupled bio-physical processes in estuarine and coastal regions. These include routines for marsh vulnerability to waves, estuarine biogeochemistry, and feedbacks between aquatic vegetation and hydrodynamics.
Idealized COAWST numerical model for testing marsh wave thrust and lateral retreat dynamics routines
There are two idealized domains developed in this work to test the marsh dynamics in the COAWST modeling framework.
1. First idealized domain is to test and verify the lateral thrust calculations.
2. Second idealized domain is to test the implementation of lateral retreat formulations
COAWST model of Barnegat Bay creeks to demonstrate marsh dynamics
The COAWST modeling framework was extended to add two key processes that affect marshes, erosion due to lateral wave thrust (LWT) and vertical accretion due to biomass productivity. The testing of the combined effects of integrating these two processes was done by modeling marsh complexes within Forsythe National Wildlife Refuge and the Barnegat Bay estuary, New Jersey.
Wave thrust values at point locations along the shorelines of Massachusetts and Rhode Island
This product provides spatial variations in wave thrust along shorelines in Massachusetts and Rhode Island. Natural features of relevance along the State coast are salt marshes. In recent times, marshes have been eroding primarily through lateral erosion. Wave thrust represents a metric of wave attack acting on marsh edges.
Wave thrust values at point locations along the shorelines of Chesapeake Bay, Maryland and Virginia
This product provides spatial variations in wave thrust along shorelines in the Chesapeake Bay. Natural features of relevance along the Bay coast are salt marshes. In recent times, marshes have been eroding primarily through lateral erosion. Wave thrust represents a metric of wave attack acting on marsh edges. The wave thrust is calculated as the vertical integral of the dynamic pressure of...
Modeling marsh dynamics using a 3-D coupled wave-flow-sediment model
Salt marshes are dynamic biogeomorphic systems that respond to external physical factors, including tides, sediment transport, and waves, as well as internal processes such as autochthonous soil formation. Predicting the fate of marshes requires a modeling framework that accounts for these processes in a coupled fashion. In this study, we...
Kalra, Tarandeep S.; Ganju, Neil Kamal; Aretxabaleta, Alfredo; Carr, Joel A.; Defne, Zafer; Moriarty, Julia Quantifying slopes as a driver of forest to marsh conversion using geospatial techniques: Application to Chesapeake Bay coastal-plain, USA
Coastal salt marshes, which provide valuable ecosystem services such as flood mitigation and carbon sequestration, are threatened by rising sea level. In response, these ecosystems migrate landward, converting available upland into salt marsh. In the coastal-plain surrounding Chesapeake Bay, United States, conversion of coastal forest to salt...
Molino, Grace Damore; Defne, Zafer; Aretxabaleta, Alfredo; Ganju, Neil Kamal; Carr, Joel A. A non-linear relationship between marsh size and sediment trapping capacity compromises salt marshes’ resilience to sea-level rise
Global assessments predict the impact of sea-level rise on salt marshes with present-day levels of sediment supply from rivers and the coastal ocean. However, these assessments do not consider that variations in marsh extent and the related reconfiguration of intertidal area affect local sediment dynamics, ultimately controlling the fate of the...
Donatelli, Carmine; Zhang, Xiaohe; Ganju, Neil Kamal; Aretxabaleta, Alfredo; Fagherazzi, Sergio; Leonardi, Nicoletta Spatiotemporal variability of light attenuation and net ecosystem metabolism in a back-barrier estuary
Quantifying system-wide biogeochemical dynamics and ecosystem metabolism in estuaries is often attempted using a long-term continuous record at a single site or short-term records at multiple sites due to sampling limitations that preclude long-term monitoring. However, differences in the dominant primary producer at a given location (e.g.,...
Ganju, Neil Kamal; Testa, Jeremy; Suttles, Steven E.; Aretxabaleta, Alfredo A geospatially resolved wetland vulnerability index: Synthesis of physical drivers
Assessing wetland vulnerability to chronic and episodic physical drivers is fundamental for establishing restoration priorities. We synthesized multiple data sets from E.B Forsythe National Wildlife Refuge, New Jersey, to establish a wetland vulnerability metric that integrates a range of physical processes, regulatory information and physical/...
Defne, Zafer; Aretxabaleta, Alfredo; Ganju, Neil Kamal; Kalra, Tarandeep S.; Jones, Daniel K.; Smith, Kathryn Using the Lomb-Scargle method for wave statistics from gappy time series
Sandwich Town Neck Beach in Sandwich, MA, has experienced substantial erosion and has been the subject of efforts by the town and private landowners to limit the sand loss. Erosion has been particularly dramatic in the past five years with the loss of dwellings. Sandwich's nourishment efforts presented a unique opportunity for scientists at the U....
Martini, Marinna A.; Aretxabaleta, Alfredo; Sherwood, Christopher R. Spatial distribution of water level impact to back-barrier bays
Water level in semi-enclosed bays, landward of barrier islands, is mainly driven by offshore sea level fluctuations that are modulated by bay geometry and bathymetry, causing spatial variability in the ensuing response (transfer). Local wind setup can have a secondary role that depends on wind speed, fetch, and relative orientation of the wind...
Aretxabaleta, Alfredo; Ganju, Neil Kamal; Defne, Zafer; Signell, Richard P. Physical response of a back-barrier estuary to a post-tropical cyclone
This paper presents a modeling investigation of the hydrodynamic and sediment transport response of Chincoteague Bay (VA/MD, USA) to Hurricane Sandy using the Coupled Ocean-Atmosphere-Wave-Sediment-Transport (COAWST) modeling system. Several simulation scenarios with different combinations of remote and local forces were conducted to identify the...
Beudin, Alexis; Ganju, Neil Kamal; Defne, Zafer; Aretxabaleta, Alfredo Sensitivity analysis of a coupled hydrodynamic-vegetation model using the effectively subsampled quadratures method
Coastal hydrodynamics can be greatly affected by the presence of submerged aquatic vegetation. The effect of vegetation has been incorporated into the Coupled-Ocean-Atmosphere-Wave-Sediment Transport (COAWST) Modeling System. The vegetation implementation includes the plant-induced three-dimensional drag, in-canopy wave-induced streaming, and the...
Kalra, Tarandeep S.; Aretxabaleta, Alfredo; Seshadri, Pranay; Ganju, Neil K.; Beudin, Alexis Observations and a linear model of water level in an interconnected inlet-bay system
A system of barrier islands and back-barrier bays occurs along southern Long Island, New York, and in many coastal areas worldwide. Characterizing the bay physical response to water level fluctuations is needed to understand flooding during extreme events and evaluate their relation to geomorphological changes. Offshore sea level is one of the...
Aretxabaleta, Alfredo; Ganju, Neil K.; Butman, Bradford; Signell, Richard P. Progress and challenges in coupled hydrodynamic-ecological estuarine modeling
Numerical modeling has emerged over the last several decades as a widely accepted tool for investigations in environmental sciences. In estuarine research, hydrodynamic and ecological models have moved along parallel tracks with regard to complexity, refinement, computational power, and incorporation of uncertainty. Coupled hydrodynamic-ecological...
Ganju, Neil K.; Brush, Mark J.; Rashleigh, Brenda; Aretxabaleta, Alfredo L.; del Barrio, Pilar; Grear, Jason S.; Harris, Lora A.; Lake, Samuel J.; McCardell, Grant; O'Donnell, James; Ralston, David K.; Signell, Richard P.; Testa, Jeremy; Vaudrey, Jamie M. P. Estimating time-dependent connectivity in marine systems
Hydrodynamic connectivity describes the sources and destinations of water parcels within a domain over a given time. When combined with biological models, it can be a powerful concept to explain the patterns of constituent dispersal within marine ecosystems. However, providing connectivity metrics for a given domain is a three-dimensional problem...
Defne, Zafer; Ganju, Neil K.; Aretxabaleta, Alfredo
Coupled-Ocean-Atmosphere-Wave-Sediment Transport (COAWST) Modeling System
The Coupled-Ocean-Atmosphere-Wave-Sediment Transport (COAWST) Modeling System is an agglomeration of open-source modeling components that has been tailored to investigate coupled processes of the atmosphere, ocean, and waves in the coastal ocean.
Hurricane Sandy Impacts Did Not Contribute to Subsequent Storm Flooding
Flooding in coastal areas bordering Great South Bay, N.Y. and Barnegat Bay, N.J. caused by winter storms that occurred following Hurricane Sandy was not influenced by changes Sandy made to barrier islands or other bay features, according to a new U.S. Geological Survey study.