29 Nov 2023

Vehicle Modeling in Unreal Engine 4

Abstract: Vehicle modeling software has presented considerable challenges in properly representing vehicle mobility in extreme conditions. We have recently been developing new vehicle models and scenes in Unreal Engine. Unreal Engine is best known as a video game creation platform focused on graphics and has relatively few options for real world accurate physics modeling. UE4 allows for lots of customization internally or via supplemental C++ code, so this can be mitigated by the addition of various functions to account for different situations a vehicle might be in. We have successfully implemented the following: accurately functioning wheeled vehicles, tracked vehicles, and created simulated and real world environments, downloaded through Geowatch heightmaps. Each environment can have various terrain conditions including soil, rock, snow, and sand applied across its surface. Modeling snow in these environments is of particular interest and recent motion resistance and sinkage models have been integrated into the software to affect graphics and vehicle performance. This new model for vehicle mobility offers an opportunity to improve the physics and graphics of differing terrains especially for winter conditions. The new model also allows for features to be updated and added with ease in the future.

28 Nov 2023

Investigation of Steam Adsorption Chillers to Modernize Existing Central Steam Plant Systems

Abstract: This report investigates the integration of steam adsorption chillers as a modernization strategy for conventional central steam plant systems. Our objective is to assess the feasibility, advantages, and challenges of incorporating steam adsorption chillers into existing steam plant setups to enhance energy efficiency and cooling capabilities. Central steam plant systems have historically been used for steam-based heating but often lack cooling capabilities, necessitating additional cooling infrastructure. Steam adsorption chillers offer a potential solution by using waste steam for cooling, optimizing energy utilization and reducing reliance on traditional cooling methods. Through a comprehensive analysis, this report evaluates the technical compatibility and potential cost implications of implementing steam adsorption chillers. It explores factors such as system integration, operational dynamics, and maintenance requirements to provide a holistic view of the feasibility and benefits of this modernization approach. The findings aim to offer valuable insights to decision-makers and Army facility managers seeking innovative ways to upgrade central steam plant systems. By considering the technical and economic aspects of adopting steam adsorption chillers, this report contributes to the knowledge base for sustainable and efficient energy utilization in central plant operations.

17 Nov 2023

Advancing Engineering With Nature Initiatives in Point Hope, Alaska

Purpose: Growing environmental risk threatens communities in cold regions, particularly as climate change contributes to permafrost thaw, a reduction in sea-ice extent, and some of the largest rates of coastal erosion on earth. In the context of these significant and growing risks, the Engineering With Nature® (EWN®) program formed its cold regions work unit in 2021 to explore the potential to apply EWN approaches in these areas to mitigate environmental risk while supporting resilient outcomes. The work unit’s objectives include working with communities to preserve the natural environment and traditions, advancing the work unit’s understanding of cold-region environments, and providing guidance on the implementation of natural and nature-based features (NNBF) and EWN in cold regions to increase resilience. This technical note (TN) provides an overview of the EWN in cold regions technical approach as applied to Point Hope, Alaska, which includes community engagement, the integration of traditional ecological knowledge (TEK) throughout the project, and the development of cold-regions-specific knowledge and tools.

31 Oct 2023

Establishing a Series of Dust Event Case Studies for East Asia

Abstract: Dust aerosols have a wide range of effects on air quality, health, land-management decisions, aircraft operations, and sensor data interpretations. Therefore, the accurate simulation of dust plume initiation and transport is a priority for operational weather centers. Recent advancements have improved the performance of dust prediction models, but substantial capability gaps remain when forecasting the specific location and timing of individual dust events, especially extreme dust outbreaks. Operational weather forecasters and US Army Engineer Research and Development Center (ERDC) researchers established a series of reference case study events to enhance dust transport model evaluation. These reference case studies support research to improve modeled dust simulations, including efforts to increase simulation accuracy on when and where dust is lofted off the ground, dust aerosols transport, and dust-induced adverse air quality issues create hazardous conditions downstream. Here, we provide detailed assessments of four dust events for Central and East Asia. We describe the dust-event lifecycle from onset to end (or when dust transports beyond the area of interest) and the synoptic and mesoscale environ-mental conditions governing the process. Analyses of hourly reanalysis data, spaceborne lidar and aerosol optical depth retrievals, upper-air soundings, true-color satellite imagery, and dust-enhanced false-color imagery supplement the discussions.

31 Oct 2023

Energy Atlas—Mapping Energy-Related Data for DoD Lands: Phase 3—Data and Portal Expansion: Northeast CONUS

Abstract: The DoD is a significant land user in northeast United States overseeing approximately 375 k acres of land with a total value of $113 B. The Department of Energy has found that major impacts from climate change will threaten energy infrastructure in the northeast US moving into the future. Current spatial information related to the energy resources and infrastructure on and adjacent to DoD installations can play a vital role in decision-making for sustainable and resilient installation planning in the region. The Energy Atlas (EA) portal provides a secure value-added resource to inform the decision-making process for current and future investment in installation infrastructure, energy management, and improvements to energy resiliency and sustainability. The EA aggregates spatial data for energy, infrastructure, and related environmental resources and facilitates access to that information through a secure online portal. The EA is hosted on a Common Access Card–authenticated portal accessible to DoD decision-makers and their partners through the Intelligence Community Geographic Information System (GIS) portal. The expansion of data coverage within the EA portal helps the DoD account for energy in contingency planning, acquisition, and lifecycle requirements in the northeast US and ensures facilities can maintain operations in the face of disruption.

31 Oct 2023

Stage Frequency Analysis from Snowmelt Runoff near Utqiaġvik, Alaska

Abstract: For the village of Utqiaġvik, located at the North Slope of Alaska, a stone-armored revetment along the coastline is proposed to reduce coastal erosion. The inner drainage capacity of the revetment must be sufficient to handle seasonal runoff from snowmelt. For this effort, we investigated the snowmelt runoff and the hydraulic impact at the watershed outlet using numerical snow and hydraulic modeling of the study area. We validated the snow model results by comparing simulated snow water equivalent (SWE) values to field measurements. Additionally, the snow model was validated using satellite-based Moderate Resolution Imaging Spectroradiometer (MODIS) snow-covered area (SCA) products and time-lapse camera imagery during snowmelt. Our results indicate that the simulated SWE and snowmelt dates agree closely with measured values. The timing of modeled runoff onset was less accurate due to natural processes that delay snowmelt runoff such as snow dams and refreeze. The effect of the uncertainty from both runoff timing and volume was addressed with a Monte Carlo simulation of stage-frequency curves for the lagoons that receive snowmelt runoff. These stage-frequency curves can be used directly in the design of outlet, drainage or discharge structures for the proposed revetment.

20 Oct 2023

Phase I Geothermal Opportunities Assessment of the Delta Junction Area, Alaska

Abstract: To enhance energy resilience at military installations in Interior Alaska, we are exploring geothermal energy, which harvests Earth’s heat to provide thermal energy, electricity, or both. Parts of Interior Alaska have high subsurface heat flow, likely related to high-heat-producing granites. While electric load is usually the focus of energy resilience; in cold regions, the thermal load dominates energy demand, and operations can be sensitive to it. A local geothermal energy source enhances energy resilience by providing baseload energy and lessening supply chain demand. Geothermal energy technology is mature and often economical, but resource location and assessment remain challenging. We present exploration methods for a geothermal feasibility study for Interior Alaska and Phase I prefeasibility study results assessing opportunities to develop geothermal at Fort Greely, Alaska. We present possible geothermal resource types, their potential uses, likelihood of existence, and development risk. We also present custom methodology for locating the resources, associated uncertainty, and the impact of finding each resource. Phase I shows geothermal at Fort Greely survives the elimination test. Investment into a Phase II field study to address knowledge gaps should consider the higher risk in comparison to other geothermal plays due to new methodology and sparse existing data.

29 Sep 2023

Arctic Seed Sterilization and Germination

Abstract: We conducted growth chamber experiments to overcome challenges of native seed germination relating to disease and germination time. We selected five northern species, Eriophorum vaginatum, E. virginicum, Anemone patens var. multifida, Polemonium reptans, and Senecio congestus, for their native ranges and commercial-nursery availability. Recommended stratification time for each species was either unknown or a minimum of 60 days. Seeds were sterilized with 70% ethanol, 10% hydrogen peroxide, or UVC light to identify which method most effectively prevented pathogen infection. To determine if stratification time could be reduced, seeds underwent a 30-day cold, moist stratification. We tested which growth medium was most conducive to germination of the sterilized, stratified seeds: filter paper or sterilized potting soil. In a separate experiment, we tested if three different levels of gibberellic acid (GA3; 0, 500, and 1000 ppm) could reduce stratification time to 15 days. The 70% ethanol was effective in a seed surface sterilization; an average of 84% of all seeds for all species treated showed no contamination. Germination following a 30-day cold, moist stratification was unsuccessful for most species tested in both growth media. Here, 1000 ppm GA3 with a 15-day cold, moist stratification showed considerable success with P. reptans.

29 Sep 2023

Microbial Activity in Dust-Contaminated Antarctic Snow

Abstract: During weather events, particles can accumulate on the snow near the Pegasus ice and Phoenix compacted-snow Runways at the US McMurdo Station in Antarctica. The deposited particles melt into the surface, initially forming steep-sided holes, which can widen into patches of weak and rotten snow and ice. These changes negatively impact the ice and snow runways and snow roads trafficked by vehicles. To understand the importance of microbes on this process, we examined deposited dust particles and their microbial communities in snow samples collected near the runways. Snow samples were analyzed at the Cold Regions Research and Engineering Laboratory where we performed a respiration study to measure the microbial activity during a simulated melt, isolated microorganisms, examined particle-size distribution, and performed 16S rRNA gene sequencing. We measured higher levels of carbon dioxide production from a sample containing more dust than from a sample containing less dust, a finding consistent with viable dust-associated microbial communities. Additionally, eleven microorganisms were isolated and cultured from snow samples containing dust particles. While wind patterns and satellite images suggest that the deposited particles originate from nearby Black Island, comparisons of the particle size and chemical composition were inconclusive.

29 Sep 2023

Plant Phenology Drives Seasonal Changes in Shear Stress Partitioning in a Semi-Arid Rangeland

Abstract: Accurate representation of surface roughness in predictive models of aeolian sediment transport and dust emission is required for model accuracy. While past studies have examined roughness effects on drag partitioning, the spatial and temporal variability of surface shear velocity and the shear stress ratio remain poorly described. Here, we use a four-month dataset of total shear velocity (u*) and soil surface shear velocity (us*) measurements to examine the spatiotemporal variability of the shear stress ratio (R) before, during, and after vegetation green-up at a honey mesquite (Prosopis glandulosa Torr.) shrub-invaded grassland in the Chihuahuan Desert, New Mexico, USA. Results show that vegetation green-up, the emergence of leaves, led to increased drag and surface aerodynamic sheltering and a reduction in us* and R magnitude and variability. We found that us* decreased from 20% to 5% of u* as the vegetation form drag and its sheltering effect increased. Similarly, the spatiotemporal variability of R was found to be linked directly to plant phenological phases. We conclude that drag partition schemes should incorporate seasonal vegetation change, via dynamic drag coefficients and/or R, to accurately predict the timing and magnitude of seasonal aeolian sediment fluxes.