2 Apr 2026

Analyzing Historical Snow Trends in Interior Alaska

Abstract: This study examines 40 years (water years 1982–2021) of snowpack characteristics to consider its hydrological implications in the 5350 km² Chena River basin. Using observations and a fine-scale physics model, we analyzed trends of snow water equivalent (SWE), snow onset and disappearance, and snow cover duration (SCD). New hydrological insights for the region: Results indicate a decline in SWE across the modeled domain, averaging a decrease of 3 mm per decade, with larger decreases (up to 10 mm per decade) at lower elevations. While domain-averaged SWE trends were not statistically significant, observed SCD showed statistically significant decreases: - 5.2, - 5.0, and - 4.4 days per decade at Teuchet Creek, Fairbanks F.O., and Little Chena Ridge, respectively. Notably, observations at SNOTEL stations and modeling revealed no statistically significant change in domain-averaged Rain-on-Snow (ROS) events over the 40-year period, contrasting some regional future estimates of increased ROS frequency. Peak streamflow did not consistently correlate with peak SWE levels, suggesting that other environmental factors such as ROS events and rapid temperature increases (e.g., a 10◦C spike observed in 1992) are key drivers of hydrological outcomes. These findings improve understanding of complex subarctic hydrological processes impacting permafrost and highlight the need for adaptive water resource management to mitigate multi-factor risks like flooding and wildfire, requiring proactive planning.

26 Mar 2026

Complete Genomic Sequences of Nine Bacillota Isolated from Alaskan Permafrost

Abstract: A total of nine Bacillota bacteria were isolated from Alaskan permafrost, and complete genomic sequences were obtained via hybrid assembly of long and short reads (Oxford Nanopore and Illumina paired-end sequencing, respectively). These genomes highlight the diversity of Arctic Bacillota and their potential applications in biotechnology.

19 Mar 2026

Compressed Snow Blocks: A Proof-of-Concept Study for Adapting Earth Block Technology for Cold Regions

Abstract: Snow construction plays a crucial role in military operations in cold regions, providing tactical fortifications, thermal insulation, and emergency infrastructure in environments where conventional building materials are scarce or require extensive infrastructure to support. Research into optimized snow compaction techniques has informed the design of snow-based protective structures, runways, and shelters. This study tested whether a conventional compressed earth block (CEB) machine could be used to produce compressed snow blocks (CSBs) suitable for construction applications in cold environments. The machine successfully formed CSBs with relatively consistent dimensions (i.e., block height), demonstrating feasibility and reliability in shaping snow for structural purposes. Density measurements of the snow blocks were more consistent with ice, indicating potential viability in load-bearing applications, but suggesting that the pressure applied during production may not be necessary to reach sufficient block strength depending on its intended end-use. While mechanical strength was not assessed, these initial findings support further investigation into optimizing this new snow compaction technique, the material properties, and block durability under environmental stressors (e.g., temperature fluctuations). Additional testing and development are required to refine this approach for faster, more efficient snow compaction for sustainable construction in cold regions.

19 Mar 2026

Arctic and Subarctic Zonal Characterization and Operational Thresholding (AZCOT)

Abstract: The US military develops and updates environmental parameters specified for the sustainment of operations throughout the world. These requirements are generally based on environmental data providing a baseline of temperature, wind, and precipitation expectations for each location. Observational data for Arctic regions is limited because of the remote and sparsely occupied geographical conditions. To address the need for updating these requirements, a 30-year analysis of meteorological conditions was conducted using a European Centre for Medium-Range Weather Forecasts (ECMWF) global reanalysis dataset over the Arctic and Subarctic region, defined by latitude 60°–90° North for this project. Raw hourly datasets were acquired, and the minimum temperatures, maximum wind speeds, maximum snow depths, and averages were determined over the period 1991–2020 between the months of October and March for each parameter. These were then visualized with geospatial analysis, producing a variety of maps designed to assist with the classification of parameters in Arctic zones of operation across a range of temporal resolutions. Finally, a review of operational limits for military equipment was conducted to match northern zones of operation with suitable capabilities dependent on environmental conditions.

18 Mar 2026

An Updated Irwin Sensor for Measurement of Surface Shear Velocity

Abstract: Accurate and efficient collection of field data related to aeolian processes is critical for improving wind erosion predictions and related management decisions. The Irwin sensor has been used in numerous wind tunnel and field studies to indicate surface shear velocity. However, the sensitivity of the sensor makes them difficult to maintain in a range of environmental conditions. This study presents a new generation of Irwin sensor incorporating updated electronics, battery operation, wireless data transmission, and streamlined field deployment and removal. A total of 20 sensors were manufactured and calibrated in a wind tunnel at the Engineer Research and Development Center. A subset of the sensors was calibrated using a PI-SWERL, which confirmed the two calibration methods converge on similar values for flat smooth test surfaces. The updated sensors were installed around a mesquite shrub at the Jornada Experimental Range, New Mexico, USA from February to July 2023. We found that initial data from the sensors accurately captured spatial patterns of surface shear velocity surrounding the shrub. The improvements to the sensor reduced workload for both deployment and maintenance, and reduced disturbance at the field site. We discuss potential opportunities to use the improved sensor network in a range of geomorphological research areas including quantifying aeolian sediment transport, building and parameterizing wind erosion models that incorporate spatial dependencies, and improving predictive tools for landform change.

23 Feb 2026

Ice Cutting and Removal for Cold Weather Improved Ribbon Bridge (IRB) Crossings

Frozen rivers provide an obstacle for any military force, as ice impedes the use of Improved Ribbon Bridges (IRBs) or other bridging vehicles. Finding an efficient way to cut and remove ice to allow for the emplacement of bridging assets is critical. The US Army Cold Regions Research and Engineering Laboratory’s (CRREL) Cold Weather IRB team went to Camp Grafton, North Dakota, to collect data for the North Dakota National Guard who were conducting a frozen wet gap crossing in February of 2022. Both quantitative and qualitative data were collected to evaluate strategies for ice cutting, removal, and IRB placement. After ice cutting and removal, an IRB bay was successfully placed in the frozen pond. Laboratory tests were conducted in March 2022 to examine different chainsaw chains for cutting an ice sheet grown in the Geophysical Research Facility (GRF) at CRREL. Chainsaws were determined to be an effective tool for cutting ice, and the speed and comfortability of different chains were documented. The data collected from this project will help to drive the North Dakota National Guard creation of a winter bridging course and will be used to update the Army’s Tactics Techniques and Procedures (TTPs) for cold weather bridging operations.

20 Feb 2026

Demonstration Validation of Industrial Supercritical Water Oxidation (iSCWO) PFAS Destruction Technology: Aqueous Film-Forming Foam Treatment by General Atomics (GA) iSCWO System

Abstract: The Department of Defense (DoD) is confronted with a pressing environmental challenge concerning legacy aqueous film-forming foam (AFFF) concentrate, historically used in firefighting activities. Legacy AFFF contains PFAS, which are identified as persistent environmental contaminants associated with adverse health effects. Considering increasing environmental regulations and concerns regarding human health impacts, the DoD needs to properly destroy legacy AFFF. The US Army Engineer Research and Development Center (ERDC) led a project focused on the demonstration and validation of technologies for the destruction of PFAS in AFFF. Results are presented for the treatment of 100 gal. of AFFF using the General Atomics industrial Supercritical Water Oxidation system. The demonstration showed destruction removal efficiencies (DREs) for total PFAS analyzed via total oxidizable precursor (TOP) assay (S24 PFAS), ranging from 98.5% to 99.9991%. No volatile fluorinated compounds were detected in the stack emissions as analyzed via Other Test Method 50; however, up to 6,000 ppt S51 PFAS as analyzed via TOP assay was detected in demister effluent. The energy consumed per cubic meter of AFFF and order of magnitude S24 PFAS destroyed ranged from 2 to 24 MWh, while the energy consumed per gram of S24 PFAS destroyed ranged from 0.046 to 48 MWh.

18 Feb 2026

Infection Risk Assessment for Socially Structured Population Using Stochastic Microexposure Model

Abstract: Predicting infection outbreak dynamics within local microenvironments is a challenging task. Some methods assume smaller population pools and often lack the statistical power of inferences. Others are designed for larger population pools and cannot be downscaled to accommodate the details of microenvironments. Practicable infection risk assessment models should account for population size, geometry and occupancy of public places, behavioral and professional patterns of daily routines, and societal structure. This study is based on the stochastic microexposure model, which has been generalized to describe clustered populations. The methodology is demonstrated for a community of several thousand students on campus. The results indicate the social structure has the first order effect on the spread of the infection. Depending on the number, size, and degree of inner- and outer-cluster connections, the outbreak exhibits distinct durations, power, and multiple peaks of infection. Moreover, the contribution of different microenvironments to infection risk evolves during the course of the outbreak. Social structure plays a major role in infection spread and should be accounted for in risk prediction tools. The stochastic microexposure model accounts for the social structure of a population at multiple scales and can predict the dynamic contributions of different microenvironments to infection spread risks.

9 Feb 2026

Ice-Resistant Breakwater Rock Sizing at Elim, Alaska

Abstract: The Elim Subsistence Harbor project requires breakwaters capable of withstanding wave action and sea ice forces in Norton Bay, Alaska. This study analyzed meteorological data, satellite imagery, and ice formation patterns to determine appropriate armor stone sizing based on ice forces for the proposed breakwaters. Analysis revealed that Elim experiences predominantly northerly winds during winter, with southwesterly components developing during the May–June breakup period. Offshore ice breakup occurs earlier at Elim (late March) than at Nome (late April). Using the Modified Stefan Equation calibrated with field measurements, end-of-season ice thickness near shore averages 1.4 m. Ice forces at Elim are expected to be less severe than at Nome because of wind patterns and directional constraints, with primary concerns limited to ice approaching from southwest directions during breakup. Using empirical evidence from Nome Harbor and physical model studies, we recommend a zoned armoring approach using 8-ton stone for toes and 4-ton stone on slopes in ice-exposed areas as minimum protection, or 8-ton stone throughout ice-exposed zones for enhanced durability. Relatively steep slopes (1.5H:1V to 2H:1V) should be maintained to encourage protective rubble ramp development during ice interactions.

5 Feb 2026

Evaluating Snow Pavement Strength in Remote Cold Environments via California Bearing Ratio (CBR) and Russian Snow Penetrometer (RSP) Combined Testing

Abstract: Accurate assessment of compacted snow strength is critical for ensuring the safety and performance of snow runways in cold environments. The Russian Snow Penetrometer (RSP) is widely used in snow science and engineering due to its simplicity, portability, and capability for rapid field measurements under extreme conditions. Conversely, the California Bearing Ratio (CBR) test remains the benchmark for evaluating the load-bearing capacity of conventional granular materials but is seldom applied to snow because of logistical constraints and the material’s complex mechanical behavior. The relationship between these two pavement evaluation tools remains poorly defined. This work investigates how RSP strength indices relate to CBR measurements to determine whether the RSP can serve as a practical proxy for snow pavement load-bearing capacity. Side-by-side field measurements of snow pavement strength were collected over a 30 h period at two test section locations. Both methods captured temporal strength increases and spatial variability, with consistently higher values at the second site attributed to extended sintering. A moderate linear correlation (R2 = 0.44) between RSP and CBR results supports a quantifiable relationship between the two methods. These findings begin to bridge the gap between conventional pavement testing and snow-specific strength evaluation, demonstrating the potential of the RSP for rapid assessment of snow runways. Continued data collection and analysis will refine this relationship and strengthen its applicability for operational use.