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Despite its extreme remoteness, the geographic North Pole is attracting more tourists than ever before, bringing increasing numbers of people and ships to the Arctic Ocean. This growth is regarded as potentially damaging to the Arctic environment, especially combined with the effects of climate change on the sea ice. Yet, to understand and anticipate future changes related to increasing tourism at the North Pole (and the Arctic Ocean), it is critical to both assess the current situation of tourism and to anticipate the future of tourism in the region in light of climate change projections. Therefore, this article explores the dimensions and geographies of tourism development at the North Pole, and more generally in the Arctic Ocean, in terms of modes of tourism, itineraries, and estimated numbers of tourists. To do so, we examine three main forms of tourism taking place in the region, namely icebreaker cruises, frontier travelers venturing on the sea ice, and ice camps. The article also aims to discuss the future of tourism in the region in light of estimated climate change impacts on the sea ice, in order to better plan and adapt to a future seasonally ice-free Arctic Ocean. [ABSTRACT FROM AUTHOR]

With the ongoing decline in Arctic sea ice extent, the accurate simulation of Arctic sea ice in coupled models remains an important problem in climate modelling. In this study, the substantial CMIP6 model spread in Arctic sea ice extent and volume is investigated using a novel, process-based approach. An observational dataset derived from the Arctic Ice Mass Balance buoy (IMB) network is used to evaluate the thermodynamic and mass balance diagnostics produced by a subset of CMIP6 models, to better understand the model processes that underlie the large-scale sea ice states. Due to the sparse nature of the IMB observations, the evaluation is performed by comparing distributions of modelled and observed fluxes in the densely sampled regions of the North Pole and Beaufort Sea. We find that all fluxes are routinely biased high in magnitude with respect to the IMB measurements by nearly all models, with too much melt in summer, and too much conduction and growth in winter, even as a function of ice thickness. We also show that choices of thermodynamic parameterisation substantially influence particular fluxes in physically realistic ways, and that these effects likely modulate the large-scale relationship between ice thickness and ice growth and melt in the CMIP6 models. [ABSTRACT FROM AUTHOR]

Copyright of URVIO - Revista Latinoamericana de Seguridad Ciudadana is the property of FLACSO - Ecuador (Facultad Latinoamericana de Ciencias Sociales) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

At high latitudes, polar night is a prolonged period of seasonal darkness with the sun remaining below the horizon throughout the diel cycle for up to 177 days at the North Pole. Along with diffuse atmospheric light from the sun and the moon, bioluminescence is an in‐water light source that can facilitate ecological interactions in an otherwise dim‐light environment. At high latitudes during polar night, bioluminescence rather than sunlight represents a significant portion of the photons available in the pelagic. We investigated depths of transition zones (called the bioluminescence transition depth) in the pelagic light field during polar night, defining the transition of a light field dominated by atmospheric irradiance, to one dominated by bioluminescent point sources. We derived relationships between values of the transition depth, bioluminescence potential, surface irradiance due to atmospheric light and the diffuse attenuation coefficient. We conducted studies for two Svalbard, Norway fjords, as well as for offshore areas located in the shelf‐break, shelf‐slope and in the Arctic basin. Based on our results for two polar nights, the transition from underwater light dominated by atmospheric sources to that dominated by bioluminescence occurs between 10 and 40 m in two Svalbard fjords, and between 18 and 60 m for offshore areas. These transition depths may be of particular importance to understanding how bioluminescence structures planktonic communities both in polar regions and at lower latitudes. Plain Language Summary: The polar night is a period of continuous winter darkness north of ∼72.5°N latitude, and this period presents challenging light conditions for Arctic pelagic organisms. With the sun remaining below the horizon from one day at the Arctic Circle to 6 months at the North Pole, prolonged darkness limits light‐mediated predator prey interactions in the plankton. Bioluminescence is light produced by a photochemical reaction in organisms, and it is an in‐water light source that can facilitate ecological interactions in an otherwise dim‐light environment. We investigated depths of transition zones from a light field dominated by atmospheric irradiance, to one dominated by bioluminescent point sources, across a gradient from Svalbard fjords to the Arctic basin. Based on our results, the transition from underwater light dominated by atmospheric sources to that dominated by bioluminescence occurs between 10 and 40 m in two Svalbard fjords, and between 18 and 60 m for offshore areas. The light gradient occurring in these transition zones has ecological implications, including depth selection and predator‐prey interactions. This work provides another step in the difficult task of untangling the complex relationships among marine organisms and natural light. Key Points: We investigated depths of transition zones from one dominated by atmospheric irradiance to one dominated by bioluminescent sourcesWe derived relationships between transition depth, bioluminescence potential, surface irradiance and diffuse attenuation coefficientAt high latitudes during polar night, bioluminescence represents a significant portion of the photons available in the pelagic [ABSTRACT FROM AUTHOR]

Nova Zembla is a tall, skinny island north of Russia above the Arctic Circle. This article is about the maps that describe Nova Zembla and the geographical region surrounding it that were published from 1562 to 1650. From 1562 until 1592, all maps spelled it "Nova Zemla" and drew it either as one of the giant circumpolar islands or as a peninsula of one. Thereafter, some maps used "Zemla," and some used "Zembla," but almost all maps represented it as an independent island. This article discusses the explorers who sailed near Nova Zembla in the last half of the sixteenth century and how they created the history of the name Nova Zembla. The evolution of the spelling and shape of Nova Zembla is analogous to punctuated equilibria in paleontological evolution. Using maps containing Nova Zembla, this article shows that the Dutch-Drake La Heroike Interprinse ... map was made in the last decade of the sixteenth century, probably around 1594. [ABSTRACT FROM AUTHOR]

In recent years, there has been a notable surge in lightning events within the Arctic region. This is possibly due to the ongoing trend of global warming that is particularly pronounced in the Arctic. This study focuses on instances of rare lightning activity in the proximity to the North Pole in the last decade. We hypothesize that these occurrences are linked to augmented land heating in Eurasia rather than solely due to the increasing temperatures in the Arctic region. This assertion is substantiated by model simulations using the Weather Research and Forecasting model. [ABSTRACT FROM AUTHOR]

We present a new explicit quasi-Lagrangian integration scheme with the three-dimensional cubic spline function transform (transform = fitting + interpolation, referred to as the "spline format") on a spherical quasi-uniform longitude–latitude grid. It is a consistent longitude–latitude grid, and to verify the feasibility, accuracy, convergence, and stability of the spline format interpolation scheme for the upstream point on the longitude–latitude grid, which may map a quasi-uniform longitude–latitude grid, a set of ideal, exact test schemes is adopted, which are recognized and proven to be effective internationally. The equilibrium flow test, cross-polar flow test, and Rossby–Haurwitz wave test are used to illustrate the spline scheme uniformity to the linear scheme and to overcome the over-dense grid in the polar region and the non-singularity of the poles. The cross-polar flow test demonstrates that the geostrophic wind crosses the polar area correctly, including the South Pole and North Pole. A non-hydrostatic, fully compressible dynamic core is used to complete the density flow test, demonstrating the existence of a time-varying reference atmosphere and that the spline format can simulate highly nonlinear fine-scale transient flows. It can be compared for the two results of the density flow test between the solution with the spline format and the benchmark reference solution with the linear format. Based on the findings, the non-hydrostatic dynamic core with the spline format is recommended for adoption. When simulated for the flow over an ideal mountain, through the "topographic gravity wave test", the bicubic surface terrain and terrain-following height coordinates, time-split integration, and vector discrete decomposition can be derived successfully. These may serve as the foundations for a global, unified spline-format numerical model in the future. [ABSTRACT FROM AUTHOR]

One of the major obstacles to the continuation of life on Earth is the global climate change. The fact that our nation is experiencing a minor impact from the global climate change does not change the reality that there is no problem. It is well recognized that the polar areas are the most impacted by the global climate change, or that the triggering of the Polar Regions would have a significant influence on the whole planet. In this scenario, science teachers have a significant deal of responsibility for raising awareness of polar science subject among future generations. As a result, it is in our hands to mitigate the impacts of global climate change through increased student knowledge. The screening model was used in the study to show the knowledge and awareness levels of science teachers on polar sciences, who will supply this awareness. The "Polar Sciences Awareness Questionnaire-PSAQ" data collecting instrument, whose validity and reliability were calculated, was employed within the parameters of the study. PSAQ was created in Google Form style with web-based access. The data were collected voluntarily from 205 science teachers working in a province in the Southeastern Anatolia Region, which is the population of the study. The statistical package program SPSS 26 was used to analyze the data that had been collected. The research revealed that while science instructors were aware of the North Pole, South Pole and climate change, their awareness was not very high. It is because science instructors lack a specific education in polar sciences that they do receive explicitly. The report makes several recommendations, one of which is to include polar science learning outcomes and lessons in teacher and student education programs. [ABSTRACT FROM AUTHOR]

Arctic clouds are sensitive to atmospheric particles since these are sometimes in such low concentrations that clouds cannot always form under supersaturated water vapor conditions. This is especially true in the late summer, when aerosol concentrations are generally very low in the high Arctic. The environment changes rapidly around freeze‐up as the open waters close and snow starts accumulating on ice. We investigated droplet formation during eight significant fog events in the central Arctic Ocean, north of 80°, from August 12 to 19 September 2018 during the Arctic Ocean 2018 expedition onboard the icebreaker Oden. Calculated hygroscopicity parameters (κ) for the entire study were very high (up to κ = 0.85 ± 0.13), notably after freeze‐up, suggesting that atmospheric particles were very cloud condensation nuclei (CCN)‐active. At least one of the events showed that surface clouds were able to form and persist for at least a couple hours at aerosol concentrations less than 10 cm−3, which was previously suggested to be the minimum for cloud formation. Among these events that were considered limited in CCN, effective radii were generally larger than in the high CCN cases. In some of the fog events, droplet residuals particles did not reactivate under supersaturations up to 0.95%, suggesting either in‐droplet reactions decreased hygroscopicity, or an ambient supersaturation above 1%. These results provide insight into droplet formation during the clean late‐summer and fall of the high Arctic with limited influence from continental sources. Plain Language Summary: The Arctic atmosphere can be very clean in the summer, to the point that clouds cannot form because there are insufficient particles present for the water vapor to condense upon. This has important implications for the radiation budget, which is highly dependent on clouds. As part of the Arctic Ocean 2018 expedition in the central Arctic Ocean near the North Pole, we investigated the ability of particles to turn into droplets throughout the whole cruise (August 12 to 19 September 2018), and during eight significant fog events. Overall, we found that after the sea ice started to freeze, the particles were more capable of turning into cloud droplets. During one fog event, we observed fog droplets forming when the particle concentrations were lower than the limit that past studies had suggested that fog/cloud could be sustained. During several fog events, the dried fog droplets did not always re‐form droplets when exposed to cloud‐like conditions, which suggests that the original droplets must have formed under extreme conditions. Our results show that in the summer/fall in the high Arctic, liquid droplets sometimes form under unusual circumstances that are likely not always considered in models. Key Points: Aerosol hygroscopicity was greater after surface water freeze‐up than beforeHygroscopicity of Aitken mode particles was generally greater than accumulation mode particlesCloud droplet effective radii during aerosol‐limited periods were larger generally than periods with higher aerosol concentrations [ABSTRACT FROM AUTHOR]

We describe the model‐independent analysis technique of Mars Science Laboratory (MSL) pressure and Mars Climate Sounder (MCS) data in de la Torre Juárez et al. (2019, https://doi.org/10.22541/essoar.169945479.90436599/v1) that compared multiple years of surface pressures on Gale before, during, and after the Global Dust Storm of Mars Year 34. The analysis found (a) representative pressure scale heights over Gale; (b) that the storm was followed by a pressure deficit at Gale; (c) the following C storms did not eliminate the deficit; (d) changes in the duration of the polar caps condensation seasons, with an early start of the North Polar (NP) ice cap growing season the year before the Great Dust Storm (GDS) and a late signature of the end of the expansion season thereafter, changes consistent with a larger growth phase of the NP cap; (e) MCS observed a larger than usual NP cap; and (f) cold temperature anomalies over the NP and warm over the Southern Pole after the storm. We also show that the analysis of observed MSL pressure data alone filters out effects on the pressure signal that are attributable to dynamical and orographic processes in a recent model analysis that makes similar interpretations as our 2019 study. One additional Mars year of observations is included to eliminate early concerns about sensor drifts. Noting that a similar NP anomaly was observed with MCS data after the last early GDS in MY25, and not the later GDS of MY27, the results suggest a possible unique effect of early GDSs. Plain Language Summary: In 2018, Mars Year 34, Mars experienced a dust storm that encircled the whole planet and darkened its skies more than most storms in the recent past. Already in 2019 an analysis reported surface pressures below the climatological values observed over the previous 3 years in Gale Crater. The pressure deficit persisted into Mars Year 35 long after the end of the storm and dust over Gale had returned to levels from previous years. The storm coincided with a longer duration of the condensation season of the North Polar ice cap and a subsequent increase in its maximum amount of ice volume. We perform here a full analysis of five Mars Years of data showing how the duration of the polar caps sublimation/condensation seasons changed around the time of the storm, that the extension of the polar caps changed, and that the atmosphere above the North Pole was slightly colder than in years before the storm. Key Points: A technique to measure representative pressure scale heights at Gale enables tracking signatures of changes in the polar ice capsREMS surface pressure with Mars Climate Sounder observations are used to describe the polar processes after the great storm of Mars Year 34Multiannual pressure data show a short Southern Polar Cap growth season before the storm followed by a long Northern Polar Cap growth season [ABSTRACT FROM AUTHOR]

We derive the nonlinear governing equations for stratified circumpolar atmospheric jet flow in Saturn's upper troposphere. An exact solution is obtained in the material (Lagrangian) framework, by specifying its hypotrochoidal particle paths. The resulting flow pattern presents a striking resemblance to the hexagonal jet stream structure observed near Saturn's North Pole. [ABSTRACT FROM AUTHOR]

When the British Arctic Expedition of 1875 under command of George Nares left in search of the North Pole, they brought with them the most up-to-date photographic equipment available to the British Admiralty. Two crew members received instruction in photography from the astronomer, engineer and photographer, William Abney at Chatham, and Abney also sourced the wet and dry-plate equipment provided for the expedition. The expedition was unsuccessful in its ambitious geographical goal of reaching the North Pole, but it returned in 1876 with over 100 photographs. However, the Admiralty did not immediately release the photographs, which was a decision that was broadly criticized in the British periodical press. This was the first time an expedition had successfully returned with photographs taken in the high Arctic, so why did the Admiralty withhold the photographs? In this article, I use examples from the Illustrated London News and Nares' official travel account Narrative of A Voyage to the Polar Sea (1878) to examine the use of photography in constructing specific ideals of exploration in the context of the British Arctic Exploration of 1875. I show that the use of photography in the Arctic had been an experiment, both in terms of using new technologies while travelling in the high north, and in incorporating this new medium into the visual archives and narrative storytelling of expeditions. The use of different forms of illustrations also speaks the construction of visual authority and narratorial control in the context of imperial expansionism in the North. [ABSTRACT FROM AUTHOR]

Copyright of Geopolitica(s): Revista de Estudios Sobre Espacio y Poder is the property of Universidad Complutense de Madrid and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Military Science Review / Hadtudományi Szemle is the property of National University of Public Service and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Mechanisms behind the phenomenon of Arctic amplification are widely discussed. To contribute to this debate, the (AC)3 project was established in 2016 (www.ac3-tr.de/). It comprises modeling and data analysis efforts as well as observational elements. The project has assembled a wealth of ground-based, airborne, shipborne, and satellite data of physical, chemical, and meteorological properties of the Arctic atmosphere, cryosphere, and upper ocean that are available for the Arctic climate research community. Short-term changes and indications of long-term trends in Arctic climate parameters have been detected using existing and new data. For example, a distinct atmospheric moistening, an increase of regional storm activities, an amplified winter warming in the Svalbard and North Pole regions, and a decrease of sea ice thickness in the Fram Strait and of snow depth on sea ice have been identified. A positive trend of tropospheric bromine monoxide (BrO) column densities during polar spring was verified. Local marine/biogenic sources for cloud condensation nuclei and ice nucleating particles were found. Atmospheric–ocean and radiative transfer models were advanced by applying new parameterizations of surface albedo, cloud droplet activation, convective plumes and related processes over leads, and turbulent transfer coefficients for stable surface layers. Four modes of the surface radiative energy budget were explored and reproduced by simulations. To advance the future synthesis of the results, cross-cutting activities are being developed aiming to answer key questions in four focus areas: lapse rate feedback, surface processes, Arctic mixed-phase clouds, and airmass transport and transformation. [ABSTRACT FROM AUTHOR]

The controversy over who was the first to reach the North Pole has raged since 1909, when Frederick Cook and Robert Peary made conflicting claims. Both have had advocates and disparagers; innumerable books and articles attack, defend, and describe their adventures. What is missing, however, is a composite study on how Puck and Life, the leading American humor periodicals of the day, reflected and influenced their readers’ perspectives on related cultural issues, including “native” residents, the monetary value of the Pole itself, funding for the expeditions, and the permanent effect on social and cultural mores. While the magazines’ early focus displays a more nominal view of the impact of northern exploration (for instance, introducing terms such as “igloo” and “sleddogs,” and the use of stock Arctic sketches), later issues place a greater emphasis on the social and political repercussions of Polar discovery. To focus on the way Puck and Life reacted to the Cook/Peary controversy in their cartoons, quips, comments, and columns is to see how America in the early twentieth century became known for a growing global initiative that began in the farthest north. [ABSTRACT FROM AUTHOR]

Copyright of Novus Orbis: Journal of Politics & International Relations is the property of Karadeniz Technical University, Faculty of Economics & Administrative Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In his memoir, A Negro Explorer at the North Pole (1912), Matthew Henson describes the toll of his and Peary’s race to the Pole. This record of the 1908-09 Arctic expedition complicates established understandings of the “Dash to the Pole” and his own role as Peary’s assistant. Donald B. Macmillan declared in How Peary Reached the Pole: The Personal Story of His Assistant (2008) that Peary could not have done it without Henson (275), whose text uncovers an accomplished writer and explorer at work. The complicated character of Robert E. Peary figures prominently in his pages, though in a less independent version than in other accounts. Henson details the highly skilled labor he performs in the Arctic, and his own personality and perceptions. He shares, to a degree, the value systems of his Commander and the white members of the expedition, including the emphasis on heroic masculinity. But he also inscribes his racial heritage into his memoir, and his close, if complex, relation to the Inughuit. The result of intricate balancing acts, Henson’s silences echo in his text, revealing what could not be articulated by an African American member of Peary’s legendary expeditions. Henson’s contemporaries paid little attention to his accomplishments, since white American and European explorers dominated the field of Arctic travel, but his contribution received more attention as the 20th Century progressed. His experience suggests the costs and the crises—personal, national, and international— of a contested icescape increasingly visible and accessible in the 21st Century. [ABSTRACT FROM AUTHOR]

The aim of the study is to develop scientific and methodological provisions for assessing the investment attractiveness of the region’s development poles and their approbation on the materials of the Sughd region of the Republic of Tajikistan. At the same time, a methodology should be developed for determining and justifying the capital investment objects with the highest return of the region’s development pole and growth point. The main objective of the research paper is to assess the investment attractiveness of the development poles as objects that most effectively use the region’s limited resources. The research methods are based on the principles of system-complex, deterministic and causal approaches in combination with the principle of dynamism. In relation to the Tajik regions considered as quasi-economy, the following range of indicators has been substantiated and proposed: the region’s enterprises production total profitability; market conditions (the industry production volumes dynamics and the development poles); competitive situation (the large competitors number in the region); the ratio of profitable and unprofitable enterprises; average labour productivity; the growth locomotives presence in the region. Based on the accounting and analysis of these indicators, a comparative assessment of the investment attractiveness of the North Development Pole and the food industry of the Sughd region of the Republic of Tajikistan has been carried out. It has been proved that the investment attractiveness of the development pole is 2.3 times higher than the investment attractiveness of the food industry chosen as a base for comparison. The results of the study can be used in the regional investment policy development processes and state regulation of spatial development.

The ambiguous "conquest" of the North Pole is the core element of Mariele Neudecker's tankwork Cook and Peary (2013). The artist explores the idea of an untouched icy landscape and its roots in Western heroic narratives. In reference to an aesthetic of the sublime and modern forms of knowledge presentation, precarious voids in the viewers' longing for intact nature are questioned. By enabling the viewers to follow the ideological perspective of the polar heroes - while also illustrating their ignorance - Neudecker highlights contemporary threats to the Arctic and questions its accessibility and ownership. In doing so, the artist examines the influence of cultural imaginations of "extreme" environments within historical and current geopolitical contexts. This article traces the visualisation of the Arctic and its sensual aesthetics, starting from the period of polar explorations to current climate change. [ABSTRACT FROM AUTHOR]

Measurements of the tracers, 129I, CFC‐11, and SF6 on water samples collected in the Arctic Ocean in 2015 have been used to calculate mean ages, Γ and mixing, Δ parameters using transit time distributions (TTDs) to constrain water circulation and mixing time scales. Values of Γ and Δ determined separately using the two tracer pairs, SF6‐CFC‐11, and 129I‐CFC‐11 are in good agreement for gas solubilities estimated for saturation levels of 0.90, but agreement decreases for other gas saturation levels. Both Γ and Δ increase rapidly with increasing depth below the base of the intermediate water layer (ca. 1,000 m), but maintaining a value of Δ/Γ ≅ 1 supporting the use of this proportionality in applications of TTDs to deep ocean transport of substances such as anthropogenic carbon. Isolines of Γ = 20 years deepening to depths below 1,000 m over the flank of the Mendeleyev Ridge near the North Pole outline the bathymetrically steered, return flow of recently ventilated Atlantic Water toward Fram Strait. Basin interior waters are significantly older with the Γ = 25 years mean age isoline shallowing upward to depths above 500 m in the Makarov, Canada, and Eurasian Basins. Values of Δ remain relatively constant in the 6–10 years range in upper intermediate water across all three basins indicating that flow is principally advective and that the mixing specified by Δ likely occurs upstream of the central basins in regions proximal to the outflow from the Santa Anna Trough. Plain Language Summary: Measurements of the tracers, 129I, CFC‐11, and SF6 on water samples from the Arctic Ocean have been used to calculate mean ages, Γ, and mixing, Δ, parameters using transit time distributions (TTDs) in order to constrain water circulation and mixing time scales. Values of Γ increase with increasing water depth in Atlantic intermediate water and with distance across the Arctic Ocean from the Nordic Seas input region to the Canada Basin. The mixing parameter, Δ, is a metric that relates to the cumulative amount of tracer mixing undergone by a volume element of water. In contrast to Γ, measured values of Δ are relatively constant in arctic intermediate waters indicating strong advective transport throughout the central Arctic Ocean. Values of Γ and Δ determined separately using the tracer pairs, SF6‐CFC‐11, and 129I‐CFC‐11 are in good agreement for gas solubilities at saturation levels of 0.90, but agreement decreases for other gas saturation levels. Both Γ and Δ increase rapidly with increasing depth below the base of the intermediate water layer (ca. 1,000 m), but maintaining a value of Δ/Γ ≅ 1 supporting the use of this proportionality in applications of TTDs to deep ocean transport of anthropogenic carbon. Key Points: Measurements of 129I, CFC‐11, SF6 in Arctic Ocean used to calculate mean ages, Γ and mixing, Δ to constrain water circulation time scalesΓ sections conform to historical ideas of tracer ages; Δ nearly constant in upper intermediate water indicating strong advective flowHigh Δ values in upper halocline are congruent with nutrient maximum indicating that both are governed by winter shelf mixing processes [ABSTRACT FROM AUTHOR]

The results of an analysis and comparison of times of appearance of the features of the long-term displacement of the geographic North Pole over the Earth's surface and the components of the angular momentum of the atmosphere and global jumps in the geomagnetic field are presented. The calculations used long-term data on the motion of the geographic North Pole with intervals between readings of 0.05 years, data on the components of the angular momentum of the atmosphere, and information on the appearance of global jumps observed at all magnetic observatories of the globe. The following methods were used in the study: wavelet analysis, approximation of nonlinear trends by smooth functions, and two-channel spectral analysis. Based on the results of the analysis, a conclusion was drawn about a possible connection between the features in the nonlinear trends of the motion of the geographic North Pole over the Earth's surface and the components of the angular momentum of the atmosphere, as well as global jumps in the secular variations of the geomagnetic field in the interval of 1964–1980 with global energy rearrangements in the adjacent shells of the Earth's system. Coherence was established between variations with a period of 35.3 years in data on the variation in the position of the North Pole relative to the conditional beginning and in data on the variation in the dipole moment. The possibility of the process of their synchronization with an advance of 6 years of fluctuations in data on the variation in the dipole moment is allowed. [ABSTRACT FROM AUTHOR]

We examined mixing processes within the ice–ocean boundary layer (IOBL) close to the geographic North Pole, with an emphasis on wind‐driven sea ice drift. Observations were conducted from late August to late September 2020, during the final leg of the international Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition. Measurements of ice motion, and profiles of currents, hydrography, and microstructure turbulence were conducted. The multifarious direct observations of sea ice and the upper ocean were used to quantify the transport of momentum, heat, and salt in the IOBL. The ice drift was mostly characterized by the inertial oscillation at a semi‐diurnal frequency, which forced an inertial current in the mixed layer. Observation‐derived heat and salinity fluxes at the ice–ocean interface suggest early termination of basal melting and transitioning to refreezing, resulting from a rise in the freezing point temperature by the presence of freshened near‐surface water. Based on the friction velocity, the measured dissipation rate (ε) of turbulent energy can be approximated as 1.4–1.7 times of the "Law of the Wall" criterion. We also observed a spiraling Ekman flow and find its vertical extent in line with the estimate from ε‐based diffusivity. Following passage of a storm, the enhanced oscillatory motions of the ice drift caused trapping of the near‐inertial waves (NIWs) that exclusively propagated through the base of the weakly stratified mixed layer. We accounted Holmboe instabilities and NIWs for the observed distinct peak of the dissipation rate near the bottom of the mixed layer. Plain Language Summary: We examined how sea ice drift in the Arctic Ocean affects the movement of seawater directly under the ice, and how this impacts freezing and melting of the ice itself. During the Multidisciplinary drifting Observatory for the Study of Arctic Climate expedition, we used a number of different instruments to measure air, sea ice and ocean properties on an ice floe between late August and late September 2020. We recorded the drift tracks of the ice, and linked the ice motion to the currents, temperature and salinity within the upper 50 m of the ocean. Strong winds triggered wavy fluctuations and water mixing, in particular close to where the ice and ocean meet. During a storm in mid‐September, the ice stopped melting and started to refreeze even though the water and the air were still relatively warm. We explain this by the presence of surface water that was less salty, and therefore froze faster at higher temperature, and by the ice moving faster than usually observed in the region. In combination, these factors provided favorable conditions for sea ice formation. Our results suggest that the distribution of sea ice meltwater need to be accounted for in order to better predict Arctic sea ice conditions in the future. Key Points: Enhanced ice drift and near‐surface freshened water jointly promoted early termination of basal melting and preconditioning of refreezingTurbulent dissipation rate can be scaled by 1.4–1.7 times of the "Law of the Wall" criterion, with surface buoyancy flux being negligibleNear‐inertial wave was trapped by weakly stratified water in lower mixed layer, which produced turbulence by the Holmboe instability [ABSTRACT FROM AUTHOR]

Arctic sea ice in summer shows both interannual and long-term variations, and atmospheric circulation anomalies are known to play an important role. This study compares the summertime large-scale circulation anomalies associated with Arctic sea ice on interannual and decadal time scales. The results indicate that the circulation anomalies associated with decreased sea ice on an interannual time scale are characterized by a barotropic anticyclonic anomaly in the central Arctic, and the thermodynamic process is important for the circulation–sea ice coupling. On one hand, the descending adiabatic warming in low levels associated with the central Arctic anticyclonic anomaly leads to decreased sea ice by enhancing the downwelling longwave radiation. On the other hand, the anticyclonic anomaly also induces more moisture in low levels. The enhanced moisture and temperature (coupled with each other) further favor the reduction of sea ice by emitting more downwelling longwave radiation. By contrast, associated with the decadal sea ice decline, there is an anticyclonic anomaly over Greenland and a cyclonic anomaly over northern Siberia, and the wind-driven sea ice drift dominates the sea ice decline. The transpolar circulation anomalies between the anticyclonic and cyclonic anomalies promote transport of the ice away from the coasts of Siberia toward the North Pole, and drive the ice out of the Arctic Ocean to the North Atlantic. These circulation anomalies also induce sea ice decline through thermodynamic process, but it is not as significant as that on an interannual time scale. [ABSTRACT FROM AUTHOR]

The three infrared atmospheric sounding interferometers (IASIs), launched in 2006, 2012, and 2018, are key instruments to weather forecasting, and most meteorological centres assimilate IASI nadir radiance data into atmospheric models to feed their forecasts. The European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) recently released a reprocessed homogeneous radiance record for the whole IASI observation period, from which 13 years (2008–2020) of temperature profiles can be obtained. In this work, atmospheric temperatures at different altitudes are retrieved from IASI radiances measured in the carbon dioxide absorption bands (654–800 and 2250–2400 cm -1) by selecting the channels that are the most sensitive to the temperature at different altitudes. We rely on an artificial neural network (ANN) to retrieve atmospheric temperatures from a selected set of IASI radiances. We trained the ANN with IASI radiances as input and the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis version 5 (ERA5) as output. The retrieved temperatures were validated with ERA5, with in situ radiosonde temperatures from the Analysed RadioSoundings Archive (ARSA) network and with EUMETSAT temperatures retrieved from IASI radiances using a different method. Between 750 and 7 hPa, where IASI is most sensitive to temperature, a good agreement is observed between the three datasets: the differences between IASI on one hand and ERA5, ARSA, or EUMETSAT on the other hand are usually less than 0.5 K at these altitudes. At 2 hPa, as the IASI sensitivity decreases, we found differences up to 2 K between IASI and the three validation datasets. We then computed atmospheric temperature linear trends from atmospheric temperatures between 750 and 2 hPa. We found that in the past 13 years, there is a general warming trend of the troposphere that is more important at the poles and at mid-latitudes (0.5 K/decade at mid-latitudes, 1 K/decade at the North Pole). The stratosphere is globally cooling on average, except at the South Pole as a result of the ozone layer recovery and a sudden stratospheric warming in 2019. The cooling is most pronounced in the equatorial upper stratosphere (- 1 K/decade). This work shows that ANN can be a powerful and simple tool to retrieve IASI temperatures at different altitudes in the upper troposphere and in the stratosphere, allowing us to construct a homogeneous and consistent temperature data record adapted to trend analysis. [ABSTRACT FROM AUTHOR]

Low-salinity waters in the upper Arctic Ocean, referred to as "freshwaters", are cold and play a major role in isolating the sea ice cover from the heat stored in the salty Atlantic Waters (AWs) underneath. We examined changes in Arctic freshwater distribution and circulation since 2007 using the 1/12° global Mercator Ocean operational model. We first evaluated model simulations over the upper water column in the Arctic Ocean, using nearly 20,000 independent in situ temperature-salinity profiles over the 2007-2020 period. Simulated hydrographic properties and water mass distributions were in good agreement with observations. Comparison with long-term mooring data in the Bering Strait and Beaufort Gyre highlighted the model's capabilities for reproducing the interannual evolution of Pacific Water properties. Taking advantage of the good performance of the model, we examined the interannual evolution of the freshwater distribution and circulation over 2007-2020. The Beaufort Gyre is the major freshwater reservoir across the full Arctic Ocean. After 2012 the gyre extended northward and increased the freshwater content (FC) in the Makarov Basin, near the North Pole. Coincidentally, the FC decreased along the East Siberian slope, along with the AW shoaling, and the Transpolar Drift moved from the Lomonosov Ridge to align with the Mendeleev Ridge. We found that these changes in freshwater distribution were followed in 2015 by a marked change in the export of freshwater from the Arctic Ocean with a reduction in Fram Strait (-30%) and an increase in the western Canadian Archipelago (+16%). [ABSTRACT FROM AUTHOR]

July 2022 marks the 60th anniversary of the first mission of a Soviet submarine to the geographic North Pole. This and subsequent missions required new navigation aids to be developed. This paper studies the development of the navigation aids used in the polar missions. [ABSTRACT FROM AUTHOR]

In a recent study, a 2-D pseudospectral time-domain (PSTD) full-wave simulator was developed and demonstrated to be capable of efficiently solving large-scale low-frequency (e.g., HF) electromagnetic scattering problems, for example, on the application of radar sounding simulations of planetary clutter and subsurfaces. In this article, the 2-D PSTD simulator is applied to simulate a domain as large as 4000 $\lambda $ (along-track) $\times 1666.67\,\,\lambda $ (cross-track) $\times 33.33\,\,\lambda $ (depth) with $\lambda =15$ m at an HF frequency of 20 MHz. To accomplish the goal, the simulator is further improved to efficiently model/simulate large cross-track slices of dielectric scenes by allowing nonuniform grid sampling in horizontal (lateral) and vertical directions, and the cross-track results are then stitched together along the track to form the simulated radargram. By combining the SHAllow RADar (SHARAD) viewing geometry and Mars Orbital Laser Altimeter (MOLA) digital elevation model (DEM), we simulate SHARAD returns at three different sites on Mars: one at the North Pole and two at Oxia Planum. At all three sites, the PSTD simulated radargrams are compared with measured SHARAD radargrams. Through power-level calibration and reference time adjustment, the PSTD simulated power estimates are further validated by comparing with real power observations from SHARAD with a 5-dB uncertainty and Pearson correlation coefficient of 0.3–0.4 (a $p$ -value on the order of $10^{-9}$), which justifies the use of the 2-D PSTD simulator for emulating surface clutter in planetary radar sounding. This simulator is open source and can be easily modified to support radar sounding simulations in support of other planetary missions with radar sounding instruments. [ABSTRACT FROM AUTHOR]

The article examines the regional patterns of rifting in the Arctic and assesses the impact of large (supra-regional) rift systems on the geological evolution of the region. Against the background of the description of main Arctic structures, the Atlantic–Arctic rift system (AARS) is described as a tectonotype of a large planetary geophorm that has evolved from continental rifting to spreading proper with the development of a full-fledged ocean. The main properties of this system are its development towards the North Pole, the longitudinal orientation of the rifts, their separation by latitudinal faults, and predominantly sinistral shear displacement of individual segments. We believe that such a structure reflects the influence of the rotational factor on distribution of lithospheric masses of the Earth. Their tendency to the equilibrium position relative to the rotation axis is implemented by movements towards the equator and along it. The outflow of masses to low latitudes makes possible the growth of the rift system, but does not contribute to its further development after reaching the Pole. This phenomenon is of general nature and determines the development of all longitudinal rift systems, which leads to their spatial convergence and attenuation of dynamics in the circumpolar space. Within the Arctic region, in addition to the Atlantic–Arctic system, areas of possible termination of the West Siberian, Okhotsk–Verkhoyansk, and East Pacific rift systems are considered. It is assumed that their evolution initiated the destruction of the continental lithosphere of the Arctic region and determined the subsequent transformations of its structure. Special attention is paid to the problems of the possible influence of rifting on the hydrocarbon generation due to serpentinization of hyperbasites, when the lithosphere is penetrated by faults to the upper mantle depths, as well as on the remobilization of gases as a result of the disturbance of both gas hydrate reservoirs and permafrost. It is shown that the greatest generation of methane is generally associated with the development of faults in the cold lithosphere and serpentinization of mantle rocks. [ABSTRACT FROM AUTHOR]

The amount of ice versus supercooled water in clouds is important for their radiative properties and role in climate feedbacks. Hence, knowledge of the concentration of ice‐nucleating particles (INPs) is needed. Generally, the concentrations of INPs are found to be very low in remote marine locations allowing cloud water to persist in a supercooled state. We had expected the concentrations of INPs at the North Pole to be very low given the distance from open ocean and terrestrial sources coupled with effective wet scavenging processes. Here we show that during summer 2018 (August and September) high concentrations of biological INPs (active at >−20°C) were sporadically present at the North Pole. In fact, INP concentrations were sometimes as high as those recorded at mid‐latitude locations strongly impacted by highly active biological INPs, in strong contrast to the Southern Ocean. Furthermore, using a balloon borne sampler we demonstrated that INP concentrations were often different at the surface versus higher in the boundary layer where clouds form. Back trajectory analysis suggests strong sources of INPs near the Russian coast, possibly associated with wind‐driven sea spray production, whereas the pack ice, open leads, and the marginal ice zone were not sources of highly active INPs. These findings suggest that primary ice production, and therefore Arctic climate, is sensitive to transport from locations such as the Russian coast that are already experiencing marked climate change. Plain Language Summary: Clouds play a critical role in Earth's climate, both reflecting incoming sunlight and trapping outgoing infrared radiation. Hence, even small errors in the representation of clouds in climate models can lead to uncertainty in predictions of, for example, sea ice extent. In the Arctic, liquid clouds often exist below 0°C and cloud water droplets can exist in a supercooled liquid state. In the absence of special particles that can trigger ice formation in droplets, ice‐nucleating particles (INPs), supercooled water droplets can cool well below −35°C before spontaneously freezing. The presence of INPs can reduce the lifetime of a cloud and the amount of supercooled water in clouds, making them less reflective. Based on our knowledge of INPs in other remote oceans, we expected very low INP concentrations in the central Arctic. However, we found very high concentrations of biological INPs in the summertime North Pole. Furthermore, these INPs come from the seas off the coast of Russia, a region already experiencing strong climate change. It is possible that these sources may become even more important as the Arctic becomes increasingly ice‐free, causing changes in Arctic clouds and further changes in climate. Key Points: The concentration of ice‐nucleating particles at the North Pole in summer 2018 was amongst the highest anywhere in the worldBiological ice‐nucleating particles were derived from the Russian seas and perhaps associated with wind‐driven sea sprayThe concentration of ice‐nucleating particles at the surface was often different to that higher in the boundary layer where clouds form [ABSTRACT FROM AUTHOR]

In previous studies of more than two hundred archaeological sites, it was discovered that the alignments of almost half of the sites could not be explained, and about 80% of the unexplained sites appear to reference four locations within 30° of the North Pole. Based on their correlation with Hapgood’s estimated positions of the North Pole over the past 100,000 years, we proposed that, by association, sites aligned to these locations could be tens to hundreds of thousands of years old. That such an extraordinary claim rests on Hapgood’s unproven theory of earth crustal displacement/pole shifts is problematic, even given the extraordinary number of aligned sites (more than several hundred) that have been discovered thus far. Using a numerical model we test his hypothesis that mass imbalances in the crust due to a buildup of polar ice are sufficient to displace the crust to the extent required in his theory. We discover in the process that the crust is not currently in equilibrium with the whole earth in terms of its moments of inertia. Based on a review of the literature that reveals a possible connection between the timing of short-term reversals of the geomagnetic field (geomagnetic excursions), super-volcanic eruptions, and glacial events, we hypothesize that crustal displacements might be triggered by geomagnetic excursions that “unlock” the crust from the mantle to the extent that available forces, specifically earth–moon–sun tidal forces, the same forces that move earth’s oceans, can displace the crust over the mantle. It is demonstrated how such a model, when combined with existing climate change theory, may be able to explain periodic changes in sea level associated with the buildup and melting of polar ice over past glacial cycles by a combination of Milanković cycles and Hapgood pole shifts. [ABSTRACT FROM AUTHOR]

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This study highlights a significant methodological and practical issue involving the use of a magnetic compass in aeolian studies in the field. Geomagnetic declination can significantly affect field measurements of wind direction from anemometers as well as measurement of the orientation of geomorphic features such as sand dunes, depending on geographic location. It is therefore surprising how often methodological descriptions of published aeolian studies, including those in southern Africa, neglect to describe any declination corrections applied to field measurements or instrumental records. This results in uncertainty in the validity of data reported in such studies, particularly where actual wind directions may be very different (>20° in some cases) from measured values. Drawing from examples in the literature from southern Africa and other key locations globally, this study discusses the need for greater clarity in the declination corrections applied when wind direction is being measured and reported, especially where wind datasets from different sources are being used or integrated, or when published studies are being compared. [ABSTRACT FROM AUTHOR]