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.

27 May 2025

Naval Expeditionary Runway Construction Criteria: Evaluation of Reduced Flexural Strength Portland Cement Concrete under P-8 Traffic

Abstract: A full-scale airfield pavement test section was constructed and trafficked by the US Army Engineer Research and Development Center (ERDC) to investigate the impact of substandard flexural strength portland cement concrete (PCC) on the pavement structural support requirements for the P-8 aircraft. The substandard pavements were representative of those that may be encountered in remote locations where there may be a lack of locally available competent materials, standard construction equipment, or a skilled labor force. The test section consisted of two PCC surface thicknesses that closely matched those evaluated in previous studies utilizing standard-strength PCC. The test items were trafficked with a dual-wheel P-8 test gear on a heavy-vehicle simulator. The outcomes of the trafficking test showed a significant reduction in PCC pavement performance resulting from the reduction in flexural strength. Further, a comparison of observed performance to current pavement design and evaluation procedures suggested that current procedures may be overly conservative and may exceed a level of conservatism appropriate in a contingency environment.

23 May 2025

Laboratory and Full-Scale Testing of JETCON JC400 Rapid-Setting Concrete Repair Materials for Crater Repairs

Abstract: The DoD currently utilizes rapid-setting concrete (RSC) for a variety of applications, including capping airfield pavement repairs, to limit closure time. Laboratory and field criteria were previously developed for certifying proprietary products for use in various sizes of repairs to ensure performance under aircraft loads. A few certified products have been added to the qualified products list for larger repairs, but none are manufactured in the region near the Korean peninsula. To address this issue, a candidate Korean product (JETCON JC400) was evaluated via the established laboratory and full-scale testing protocol. One large (i.e., 15 ft × 15 ft) repair and two small (i.e., 8.5 ft × 8.5 ft) repairs were conducted and trafficked with simulated F-15E aircraft traffic. JETCON JC400 met all criteria; therefore, the authors recommended adding it to the US Air Force Qualified Products list for large and small pavement repairs. The material is compatible with all volumetric concrete mixers currently in the DoD inventory and has many other potential applications.

20 May 2025

Guidance for Managers of USACE Waterbodies: Deploying the ERDC CyanoSTUN™ for Suppression of Cyanobacterial Harmful Algal Blooms

Purpose: The purpose of this document is to guide US Army Corps of Engineers (USACE) district personnel in using the US Army Engineer Research and Development Center’s (ERDC) CyanoSTUN™ (Cyanobacterial Suppression Through Ultraviolet-Light-C Neutralization) vessel for suppression of cyanobacterial harmful algal blooms (cyanoHABs). This document describes CyanoSTUN’s capabilities and components, intended operating conditions, and instructions for safe and effective operation of the vessel.

15 May 2025

Discriminating Buried Munitions Based on Physical Models for Their Thermal Response

Abstract: Munitions and other objects buried near the Earth’s surface can often be recognized in infrared imagery because their thermal and radiative properties differ from the surrounding undisturbed soil. However, the evolution of the thermal signature over time is subject to many complex interacting processes, including incident solar radiation, heat conduction in the ground, longwave radiation from the surface, and sensible and latent heat exchanges with the atmosphere. This complexity makes development of robust classification algorithms particularly challenging. Machine-learning algorithms, although increasingly popular, often require large training datasets including all environments to which they will be applied. Algorithms incorporating an understanding of the physical processes underlying the thermal signature potentially provide improved performance and mitigate the need for large training datasets. To that end, this report formulates a simplified model for the energy exchange near the ground and describes how it can be incorporated into maximum-likelihood ratio and Bayesian classifiers capable of distinguishing buried objects from their surroundings. In particular, a version of the Bayesian classifier is formulated that leverages the differing amplitude and phase response of a buried object over a 24-hour period. These algorithms will be tested on experimental data in a future study.

14 May 2025

Autonomous Robotics Development in Robot Operating System (ROS) 2 Humble

Abstract: This report presents a novel Robot Operating System (ROS) 2–based simulation framework designed to facilitate the development and testing of an autonomous navigation stack. Elements of the navigation stack, including lidar odometry, simultaneous localization and mapping (SLAM), and frontier exploration, are discussed in detail. The key features of the navigation stack include real-time performance and scalable architecture. The simulation results were applied to a physical robot. As a result, the physical robot was able to autonomously map the interior of a building and to generate 2D occupancy and 3D point clouds of the environment.

14 May 2025

Robot Operating System Innovations in Autonomous Navigation

Abstract: This report presents the results of simulations conducted in preparation for the 2024 Maneuver Support and Protection Integration Experiments (MSPIX) demonstration. The study aimed to develop and test a system for autonomous navigation in complex environments using advanced algorithms to enable the robot to avoid obstacles and navigate safely and efficiently. The report describes the methodology used to develop and test the autonomous navigation system, including the use of simulation, to evaluate its performance. The results of the simulation tests are presented to highlight the effectiveness of the navigation solution.

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.