4 Jun 2025

Floridan Aquifer System (FAS) Aquifer Material Collection and Screening: Investigating Arsenic Fate and Transport Under Lab-Simulated Aquifer Storage and Recovery (ASR) Conditions in the FAS—Task A Report

Abstract: The US Army Engineer Research Development Center is leading a laboratory study to quantify arsenic release that could occur during large-scale aquifer storage and recovery (ASR) operations in the anoxic Floridan Aquifer System (FAS). FAS materials containing arsenic must be collected and preserved under anoxic conditions to complete the laboratory study. This report describes collection, preservation, and initial characterization results of FAS material collected. Analysis of water surrounding the FAS material during storage detected some arsenic, suggesting arsenic presence in the solids. In-depth characterization of a single sample confirmed storage conditions were anoxic; no arsenic was detected in surface scrapings collected from the sample solids. Initial characterization results suggested FAS materials collected were suitable for use in the planned laboratory study and that storage methods were suitable for preserving collected materials.

3 Jun 2025

Development and Validation of NOAA’s 20-Year Global Wave Ensemble Reforecast

Abstract: A 20-yr wave reforecast was generated based on the NOAA Global Ensemble Forecast System, version 12. It was produced using the same setup as the NCEP’s operational GEFSv12 wave component. The reforecast comprises five members with 1 cycle per day and a forecast range of 16 days. Once a week, it expands to 35 days and 11 members. This paper describes the development of the wave ensemble reforecast, focusing on validation against buoys and altimeters. The statistical analyses demonstrated very good performance in the short range for significant wave height, with correlation coefficients of 0.95–0.96 on day 1 and between 0.86 and 0.88 within week 1, along with bias close to zero. After day 10, correlation coefficients fall below 0.70. The degradation of predictability and the increase in scatter errors predominantly occur in the forecast lead time between days 4 and 10, in terms of the ensemble mean and individual members, including the control. For week 2 and beyond, a probabilistic spatiotemporal analysis of the ensemble space provides useful forecast guidance. Our results provide a framework for expanding the usefulness of wave ensemble data in operational forecasting applications.

3 Jun 2025

Development of a Wave Model Component in the First Coupled Global Ensemble Forecast System at NOAA

Abstract: We describe the development of the wave component in the first global-scale coupled operational forecast system using the Unified Forecasting System at NOAA, part of the U.S. National Weather Service operational forecasting suite. The operational implementation of the atmosphere–wave coupled Global Ensemble Forecast System, version 12, was a critical step in NOAA’s transition to the broader community-based UFS framework. GEFSv12 represents a significant advancement, extending forecast ranges and empowering the NWS to deliver advanced weather predictions with extended lead times for high-impact events. The integration of a coupled wave component with higher spatial and temporal resolution and optimized physics parameterizations enhanced forecast skill and predictability, particularly benefiting winter storm predictions of wave heights and peak wave periods. This endeavor encountered challenges addressed by the simultaneous development of new features that enhanced wave model forecast skill and product quality and facilitated by a team collaborating with NOAA’s operational forecasting centers. The GEFSv12 upgrade marks a pivotal shift in NOAA’s global forecasting capabilities, setting a new standard in wave prediction. We also describe the coupled GEFSv12-Wave component impacts on NOAA operational forecasts and ongoing experimental enhancements, which represent a substantial contribution to NOAA’s transition to the fully coupled UFS framework.

3 Jun 2025

Wind Forcing, Source Term and Grid Optimization for Hurricane Wave Modelling in the Gulf of Mexico

Abstract: This study evaluates the performance of WAVEWATCH III model driven by different wind forcing products and behavior of different parameterizations of the model’s source terms controlling energy input and dissipation and quadruplet wave-wave interactions during Hurricane Ida. We also compare the performance of the model configured on uniform unstructured and conventional non-uniform unstructured grids. Key findings show ECMWF-forecast and HRRR out-performed other products in capturing wind speeds relative to buoys, satellite and the revised Atlantic hurricane database observations. However, all products underestimated wind speeds above 20 m/s, with ECMWF and HRRR occasionally performing better for most wind speed values above 35 m/s relative to observations. The corresponding wave simulation results indicated Ida’s wave fields were better captured by model simulations with ECMWF and HRRR wind products, with biases of 2% against buoys in the Gulf of Mexico and 6% and 3% respectively against satellite data. We also highlighted limitations in bulk wave analysis by computing partial Hs and 1D spectra density differences between model and buoy for selected source terms. This reveals consistent overestimation at the lowest frequency bin and underestimation of the three higher frequency bins with a mix of negative and positive energy density difference across different frequencies.

2 Jun 2025

Future Coastal Tundra Loss due to Compounding Environmental Changes in Alaska

Abstract: Anthropogenic climate change is amplified in the Arctic, where less sea ice enables energetic wave climates while higher air and soil temperatures increase tundra erodibility. These changes are likely to exacerbate retreat of coastal tundra yet remain poorly constrained on timescales relevant to storm wave impacts. A stochastic weather generator is used to create 1,000 synthetic hourly time series of waves, water levels, offshore sea ice concentration, and air temperatures used as forcing for an efficient coastal tundra model. The ensemble set of morphological change simulations provides a probabilistic perspective on the range of tundra retreats and the relative effects of each environmental forcing. Ensembles show as the depth of the erodible layer increases, the style of tundra retreat shifts from a consistent recession to intermittent events with large magnitudes and a factor 2 range in outcomes. Model scenarios highlight shallower thaw depths narrows the range of retreats and reduces individual extreme events, but a dynamic feedback between beach slopes, wave runup, and thermally limited erosion volumes ultimately increases the number of storm events associated with retreat. The minimum tundra retreat is governed by background shoreline change and the specifics of the topographic profile dominate underlying changes in the future wave climate statistics and open water season. As the Arctic continues to warm, the change in retreat style will have significant ramifications for coastal resilience.

2 Jun 2025

Miami Harbor Entrance Channel Improvements Study: Ship Simulation Report

Abstract: The US Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory (ERDC-CHL), Ship/Tow Simulator (STS) was used to perform a navigation study assisting the US Army Corps of Engineers (USACE), Jacksonville District. The study evaluates additional navigation channel modifications from the previous 2019 study to allow larger containerships to call at the Port of Miami. This study was conducted at the CHL real-time STS. Real-time refers to the fact that model time uses a 1:1 ratio to prototype time. In addition, real-world environmental forces were simulated and acted upon the modeled ships during the study. These forces included currents, wind, bathymetry, and bank effects. Simulations for the proposed modifications were conducted at CHL for 1 week in August 2023. Four Biscayne Bay pilots participated in the validation and testing exercises. The design vessels include the MSC Daniela (14,000 twenty-foot equivalent unit [TEU]) container ship and the Maersk Guayaquil (12,000 TEU) container ship. Simulation results are presented in the form of track plots and pilot questionnaires, which were reviewed to develop the conclusions and recommendations.

13 May 2025

Development and Testing of the FRAME Tool on a 200-Mile Reach of the Lower Mississippi River

Abstract: Understanding the likely long-term evolution of the Lower Mississippi River (LMR) is a challenging mission for the US Army Corps of Engineers (USACE) that remains difficult for conventional river engineering models. A new type of model is currently in development, tasked with revealing uncertainty-bounded trends in sediment transport and channel morphology over annual, decadal, and centennial timescales. The Future River Analysis and Management Evaluation (FRAME) tool is being designed with river managers and planners in mind to provide exploratory insights into plausible river futures and their potential impacts. A unique attribute of the tool is its hybrid interfacing of traditional one-dimensional hydraulic and sediment transport modeling with geomorphic rules for characterizing the morphological response. This report documents the development of a FRAME test-bed model for a 200-mile reach of the Mississippi River upstream of Vicksburg, Mississippi. This testbed allowed development and testing of the prototype FRAME tool in a data-rich environment. This work identified proposed future developments to provide river managers and planners with a fully functional tool for delivering insights on long-term morphological response in river channels across a variety of spatial and temporal scales.

30 Apr 2025

Sediment Transport and Morphological Response to Nearshore Nourishment Projects on Wave-Dominated Coasts

Abstract: Nearshore nourishments are constructed for shoreline protection from waves, to provide sediment nourishment to the beach profile, and to beneficially use dredged sediment from navigation channel maintenance. However, it is poorly understood how placement morphology and depth influence nearshore processes operated on wave-dominated coasts. This study investigates the wave fields, sediment transport, and morphological response to three common nearshore nourishment shapes, nearshore berm (elongated bar), undulated nearshore berm, and small discrete mounds, with numerical experiments utilizing the Coastal Modeling System. The nourishments are placed in depths between 3 m and 7 m with a volume of approximately 100,000 m3 and between 400 m and 1000 m in alongshore length. Numerical experiments are carried out in three distinct coastal settings with representative wave climates and geomorphology. Simulation results indicate that shallower, more continuous berms attenuate the most wave energy, while deeper, more diffuse placements retain more sediment. Results from this study improve the understanding of nearshore nourishment shapes and can support decision makers identifying the most appropriate construction technique for future nearshore nourishment projects.

30 Apr 2025

Pier Analysis Tool: User’s Manual

Abstract: This report documents the development of a rapid structural load-capacity assessment capability for ship docking and offloading structures (i.e., piers) and automation of the assessment technique into a user-friendly personal computer–based tool referred to herein as the Pier Analysis Tool (PAT). This capability provides a quick first-cut assessment of the load-bearing capacity of pier structures in terms of maximum allowable ship mooring loads and allowable weights for typical commercial and military vehicles and equipment associated with military discharge operations. The report covers the technical basis for the structural analyses along with detailed computational examples. It also provides a detailed user guide for PAT.

30 Apr 2025

Corps Shoaling Analysis Tool (CSAT) User Guide

Abstract: The Corps Shoaling Analysis Tool (CSAT) is a suite of computational routines for evaluating shoaling rates in navigation channels maintained by the US Army Corps of Engineers (USACE). This is achieved using survey data from the eHydro enterprise hydrographic survey database. At the local scale, CSAT’s outputs are useful for understanding historical shoaling trends and identifying shoaling hotspots, while enterprise-level shoaling forecasts support Operations and Maintenance (O&M) planning over a 5-year time horizon. This user guide provides practical, step-by-step instructions for new CSAT users who wish to download, install, and run the tool. Later sections provide insight into CSAT’s advanced features while also describing the methods and assumptions that underlie the calculations.