Effects of meteorology and soil moisture on the spatio-temporal evolution of the depth hoar layer in the polar desert snowpack

In polar deserts, depth hoar (hereinafter: DH) growth is not systematic unlike on tundra and this is critical for snowpack properties. Here, we address the spatio-temporal variability of the DH layer in the polar desert at two sites in the Canadian High Arctic: Ward Hunt Island (83° N) and Resolute Bay (75° N). Our data show that, over humid areas, DH represented a larger fraction of the snowpack and was characterized by lower density and coarser crystals than over dry gravelly areas. Increased soil moisture extends the zero-curtain period during freeze-up, leading to stronger temperature gradients in the snowpack and greater kinetic metamorphism. Our results also demonstrate that the large inter-annual variability in DH is primarily driven by wind conditions in the fall since this key variable controls the initial snow density and snow onset date. These strong controls exerted by soil moisture and meteorological conditions on DH growth in polar deserts highlight the possibility of major changes in polar snowpacks physical properties in response to the rapid climate and environmental changes currently affecting these regions.

Limnological Characteristics Reveal Metal Pollution Legacy in Lakes near Canada’s Northernmost Mine, Little Cornwallis Island, Nunavut

We compared modern limnological characteristics of three lakes near the world’s northernmost base metal (lead-zinc) mine, Polaris Mine, which operated from 1981 to 2002 on Little Cornwallis Island (Nunavut, Canada), to a suite of sites from Resolute Bay (Qausuittuq), Cornwallis Island. Although both study regions are underlain by broadly similar geology and experience nearly identical climatic conditions, present-day water chemistry variables differed markedly between sites on the two islands. Specifically, the lakes near the Polaris Mine recorded substantially higher concentrations of zinc and lead, as well as several other heavy metals (cadmium, molybdenum, nickel, uranium, vanadium), relative to the sites on Cornwallis Island. Although the Polaris Mine closed in 2002, elevated levels of heavy metals in our 2017 survey are likely a legacy of contamination from prior operations.

Cryostratigraphical studies of ground ice formation and distribution in a High Arctic polar desert landscape, Resolute Bay, Nunavut

Ground ice distribution and abundance have wide-ranging effects on periglacial environments, and possible impacts on climate change scenarios. In contrast, very few studies measure ground ice in the High Arctic, especially in polar deserts and where coarse surficial material complicates coring operations. Ground ice volumes and cryostructures were determined for eight sites in a Polar desert, near Resolute Bay, Nunavut, chosen from their hydrogeomorphic classification. Dry, unvegetated polar desert sites exhibited ice content close to soil porosity, with a < 45 cm thick ice-enriched transition zone. In wetland sites, suspended cryostructures and ice dominated cryofacies (ice content at least 2x soil porosity values) were prevalent in the upper ~2 m of permafrost. Average ground ice saturation at those locations exceeded porosity values by a factor between 1.8 to 20.1, and by up to two orders of magnitude at the ~10 cm vertical scale. Sites with the highest ice content were historically submerged wetlands with a history of sediment supply, sustained water availability, and syngenetic and quasi-syngenetic permafrost aggradation. Ice enrichment in those environments were mainly caused by the strong upward freezing potential beneath the thaw front, which, combined with abundant water supply, caused ice aggradation and frost heaving to form lithalsa plateaus. Most of the sites already expressed cryostratigraphic evidence of permafrost degradation. Permafrost degradation carries important ecological ramifications, as wetland locations are the most productive, life-supporting oases in the otherwise relatively barren landscape, carrying essential functions linked with hydrological processes and nutrient and contaminant cycling.

Global Positioning System interferometric reflectometry (GPS-IR) measurements of ground surface elevation changes in permafrost areas in northern Canada

Global Positioning System interferometric reflectometry (GPS-IR) is a relatively new technique which uses reflected GPS signals to measure surface elevation changes to study frozen-ground dynamics. At present, more than 200 GPS stations are operating continuously in the Northern Hemisphere permafrost areas, which were originally designed and maintained for tectonic and ionospheric studies. However, only one site in Utqiaġvik, Alaska (formerly Barrow), was assessed to be usable for studying permafrost by GPS-IR. Moreover, GPS-IR has high requirements on the ground surface condition, which needs to be open, flat, and homogeneous. In this study, we screen three major GPS networks in Canada and identify 12 out of 38 stations located in permafrost areas as useful ones where reliable GPS-IR measurements can be obtained. We focus on the five Canadian Active Control System stations and obtain their daily GPS-IR surface elevation changes. We find that the ground surface subsided in Alert, Resolute Bay, and Repulse Bay respectively by 0.61±0.04 cm yr−1 (2012–2018), 0.70±0.02 cm yr−1 (2003–2014), and 0.26±0.05 cm yr−1 (2014–2019). At the other two sites of Baker Lake and Iqaluit, the trends are not statistically significant. The linear trends of deformation were negatively correlated with those of thaw indices in Alert, Resolute Bay, and Repulse Bay. Furthermore, in Resolute Bay, we also find that the end-of-thaw elevations during 2003–2012 were highly negatively correlated with the square root of thaw indices. This study is the first one using multiple GPS stations to study permafrost by GPS-IR. It highlights the multiple useful GPS stations in northern Canada, offering multi-year, continuous, and daily GPS-IR surface deformation, which provides new insights into frozen-ground dynamics at various temporal scales and across a broad region.

AS FOLLOWS FROM OUR MODEL THE NORTH MAGNETIC POLE IS STABLE IN ITS DRIFT

Северный магнитный полюс движется согласно модели дрейфа, предложенной канадским магнитологом Хоупом 1 и разработанной автором этой статьи 2, 3. В основе модели участие двух глобальных магнитных аномалий (ГМА): Канадской (КМА) и Сибирской (СМА). Вблизи этих ГМА расположены магнитные обсерватории: РезольютБей (RB Resolute Bay) в Канаде и Мыс Челюскин (CCh Cape Chelyskin) в России. Обсерватории регистрируют изменения величин Нкомпонент модуля геомагнитного поля (ГМП), причем в настоящее время в Канадском секторе регистрируется увеличение модуля ГМП, а в Сибирском, его уменьшение. Точка, в которой направленные навстречу векторы Нкомпонент равны друг другу, а Нкомпонента равна нулю, и есть СМП. Скорость дрейфа СМП определяется скоростью увеличения (или уменьшения) величин соответствующих ГМА. Использование этой простейшей схемы позволило автору давать очень точные прогнозы мест расположения СМП. Точно так же было определено время перехода СМП из Западного полушария в Восточное (лето 2019). Точность методики определяется исключительно точностью аппроксимации величины Нкомпонент 24. The North Magnetic Pole submits its moving to the drift model proposed by Canadian magnitologist Hope 5 and this developed by the author 6,7 which suggests an impact of two global magnetic anomalies (GMA), Canadian (CMA) and Siberian (SMA) into the pole drift. Magnetic observatories Resolute Bay, Canada, and Cape Chelyskin, Russia, located near these GMA, are recording the Hcomponent values. Nowadays increasing at the Canada area the geomagnetic field module is decreasing at the Siberia one. The NMP is the point where the vectors of Hcomponent directed towards each other are equal and the value of Hcomponent makes zero. The velocity of the NMP drift is determined by the fluctuating rate of GMA magnitudes. This technique enabled the author to predict as the NMP positions and the time of the NMP transit from the West hemisphere to the East one as 2019, summer. The technique accuracy is governed by accuracy of Hcomponent values approximation 6, 7, 13.

Geothermal Energy for Sustainable Food Production in Canada’s Remote Northern Communities

The cold, remote, northern regions of Canada constitute a challenging environment for the provision of reliable energy and food supply to communities. A transition from fossil fuels to renewables-based sources of energy is one positive step in reducing the greenhouse gases from the energy supply system, which currently requires long-distance transport of diesel for electricity and heating needs. Geothermal energy can not only displace diesel for part of this energy need, it can provide a base-load source of local energy to support food production and mitigate adverse impacts of food insecurity on communities. In this proof-of-concept study, we highlight some potential benefits of using geothermal energy to serve Canada’s northern communities. Specifically, we focus on food security and evaluate the technical and economic feasibility of producing vegetables in a “controlled environment”, using ground sources of heat for energy requirements at three remote locations—Resolute Bay, Nunavut, as well as Moosonee and Pagwa in Ontario. The system is designed for geothermal district heating combined with efficient use of nutrients, water, and heat to yield a diverse crop of vegetables at an average cost up to 50% lower than the current cost of these vegetables delivered to Resolute Bay. The estimates of thermal energy requirements vary by location (e.g., they are in the range of 41 to 44 kW of thermal energy for a single greenhouse in Resolute Bay). To attain adequate system size to support the operation of such greenhouses, it is expected that up to 15% of the annually recommended servings of vegetables can be provided. Our comparative analysis of geothermal system capital costs shows significantly lower capital costs in Southern Ontario compared to Northern Canada—lower by one-third. Notwithstanding high capital costs, our study demonstrates the technical and economic feasibility of producing vegetables cost-effectively in the cold northern climate. This suggests that geothermal energy systems can supply the heat needed for greenhouse applications in remote northern regions, supplying a reliable and robust source of cost-competitive sustainable energy over the long-term and providing a basis for improved food security and economic empowerment of communities.

GPS Interferometric Reflectometry measurements of ground surface elevation changes in permafrost areas in northern Canada

Global Positioning System Interferometric Reflectometry (GPS-IR) is a relatively new technique which uses reflected GPS signals to measure surface elevation changes to study frozen ground dynamics. At present, more than 200 GPS stations are in continuous operation in the Northern Hemisphere permafrost areas. They were originally designed and maintained for tectonic and ionospheric studies. However, only one site in Barrow, Alaska has so far been used to study permafrost by GPS-IR. Moreover, GPS-IR has high requirements on ground surface condition, which needs to be open, flat, and homogeneous. In this study, we screen 3 major GPS networks in Canada and identify 12 out of 38 stations located in permafrost areas as useful ones where reliable reflectometry measurements can be obtained. We narrow our focus to 5 Canadian Active Control System stations and obtain their daily GPS-IR estimated surface elevation changes. We find that the ground surface subsided in Alert and Resolute Bay respectively by 0.79 ± 0.04 cm yr−1 (2012–2017) and 0.70 ± 0.02 cm yr−1 (2003–2014), but uplifted in Iqaluit by 0.35 ± 0.04 cm yr−1 (2010–2017). At the other two sites respectively in Repulse Bay and Baker Lake, the trends are not statistically significant. The linear trends of deformation were negatively correlated with those of the thaw indices in Alert, Resolute Bay, and Iqaluit. Furthermore, in Resolute Bay, we also find that the end-of-thaw elevations during 2003–2012 were highly negatively correlated with the square root of thaw indices. This study highlights multiple useful GPS stations in northern Canada, where multi-year, continuous, and daily GPS-IR estimated surface deformation can be obtained and used to study frozen ground dynamics at various temporal scales and across a broad region.