12 Mar 2025

Collaborative Development of Natural and Nature-Based Solutions for Coastal Resiliency in the Arctic and Adjacent Regions: A Workshop

The workshop “Collaborative Development of Natural and Nature-Based Solutions for Coastal Resiliency in the Arctic and Adjacent Regions” was held in Reston, Virginia, October 24–25, 2023. The objective was to assemble diverse international partners in a hybrid in-person and virtual setting to focus on the viability of applying Nature-Based Solutions (NBS) to solve engineering challenges in the Arctic and similar cold region locations. The goals of the two-day workshop were to share recent efforts implementing NBS to mitigate coastal hazards such as flooding and erosion in northern high latitude settings and identify requirements and develop a robust program of activities to advance this work at national, regional, and local levels. This workshop report documents the presentations and discussion and summarizes key needs and recommendations for future engagement identified by speakers and workshop participants.

6 Mar 2025

New Construction Criteria for a Changing Arctic and Subarctic: The UFC 3-130 Series Revision Process

Abstract: The DoD operates significant and strategically important installations in the Arctic and Subarctic domain. Geopolitical, economic, and climatic changes require an upgraded ability to rapidly deploy and sustain forces into Arctic and Subarctic regions. Relevant engineering criteria and guidance to support these efforts are the Unified Facility Criteria 3-130–Arctic and Subarctic Construction (UFC 3-130) documents, originally a seven-volume series. The series has been ‘inactive’, indicating the specifications are not current and potentially technically noncompliant. Therefore, designers may resort to methods that do not meet current military or civilian standards, or they may use the outdated guidance leading to costly design and construction failures. Infrastructure owners and operators must be confident that up-to-date technology and criteria are specified to ensure life safety, mission readiness, and infrastructure longevity. This report highlights the process and resources used to generate a new five-volume UFC Arctic and Subarctic series that aligns with current technology and standards while also addressing a changing climate. These new documents are appliable for use by planners, engineers, and architects when planning, designing, constructing, and maintaining DoD infrastructure. The full UFC 3-130 series is available on the Whole Building Design Guide (WBDG) website at https://www.wbdg.org/dod/ufc.

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.

25 Oct 2022

Numerical Modeling of Mesoscale Infrasound Propagation in the Arctic

Abstract: The impacts of characteristic weather events and seasonal patterns on infrasound propagation in the Arctic region are simulated numerically. The methodology utilizes wide-angle parabolic equation methods for a windy atmosphere with inputs provided by radiosonde observations and a high-resolution reanalysis of Arctic weather. The calculations involve horizontal distances up to 200 km for which interactions with the troposphere and lower stratosphere dominate. Among the events examined are two sudden stratospheric warmings, which are found to weaken upward refraction by temperature gradients while creating strongly asymmetric refraction from disturbances to the circumpolar winds. Also examined are polar low events, which are found to enhance negative temperature gradients in the troposphere and thus lead to strong upward refraction. Smaller-scale and topographically driven phenomena, such as low-level jets, katabatic winds, and surface-based temperature inversions, are found to create frequent surface-based ducting out to 100 km. The simulations suggest that horizontal variations in the atmospheric profiles, in response to changing topography and surface property transitions, such as ice boundaries, play an important role in the propagation.

29 Dec 2021

Infrasound Propagation in the Arctic

Abstract: This report summarizes results of the basic research project “Infrasound Propagation in the Arctic.” The scientific objective of this project was to provide a baseline understanding of the characteristic horizontal propagation distances, frequency dependencies, and conditions leading to enhanced propagation of infrasound in the Arctic region. The approach emphasized theory and numerical modeling as an initial step toward improving understanding of the basic phenomenology, and thus lay the foundation for productive experiments in the future. The modeling approach combined mesoscale numerical weather forecasts from the Polar Weather Research and Forecasting model with advanced acoustic propagation calculations. The project produced significant advances with regard to parabolic equation modeling of sound propagation in a windy atmosphere. For the polar low, interesting interactions with the stratosphere were found, which could possibly be used to provide early warning of strong stratospheric warming events (i.e., the polar vortex). The katabatic wind resulted in a very strong low-level duct, which, when combined with a highly reflective icy ground surface, leads to efficient long-distance propagation. This information is useful in devising strategies for positioning sensors to monitor environmental phenomena and human activities.

30 Jun 2021

Mercury Isotopes Reveal Atmospheric Gaseous Mercury Deposition Directly to the Arctic Coastal Snowpack

Abstract: Springtime atmospheric mercury depletion events (AMDEs) lead to snow with elevated mercury concentrations (>200 ng Hg/L) in the Arctic and Antarctic. During AMDEs gaseous elemental mercury (GEM) is photochemically oxidized by halogens to reactive gaseous mercury which is deposited to the snowpack. This reactive mercury is either photochemically reduced back to GEM and re-emitted to the atmosphere or remains in the snowpack until spring snowmelt. GEM is also deposited to the snowpack and tundra vegetation by reactive surface uptake (dry deposition) from the atmosphere. There is little consensus on the proportion of AMDE-sourced Hg versus Hg from dry deposition that is released in spring runoff. We used mercury stable isotope measurements of GEM, snowfall, snowpack, snowmelt, surface water, vegetation, and peat from a northern Alaska coastal watershed to quantify Hg sources. Although high Hg concentrations are deposited to the snowpack during AMDEs, we estimate that ∼76 to 91% is released back to the atmosphere prior to snowmelt. Mercury deposited to the snowpack as GEM comprises the majority of snowmelt Hg and has a Hg stable isotope composition similar to Hg deposited by reactive surface uptake of GEM into the leaves of trees in temperate forests. This GEM-sourced Hg is the dominant Hg we measured in the spring snowpack and in tundra peat permafrost deposits.