Development of Predictive Model for Radon-222 Estimation in the Atmosphere using Stepwise Regression and Grid Search Based-Random Forest Regression

This work develops predictive models for estimating radon (222Rn) activity concentration in the atmosphere using novel grid search based random forest regression (GS-RFR) and stepwise regression (SWR). The developed models employ meteorological parameters which include the temperature, pressure, relative and absolute humidity, wind speed and wind direction as descriptors. Experimental data of radon concentration and meteorological parameters from two observatories of the Korea Polar Research Institute in Antarctica (King Sejong and Jang Bogo) have been employed in this work. The performance of the developed models was assessed using three different performance measuring parameters. On the basis of root mean square error (RMSE), the GS-RFR shows better performance over the SWR. An improvement of 64.09 % and 15.19 % was obtained on the training and test datasets, respectively at King Sejong station. At the Jang Bogo station, an improvement of 75.04 % and 28.04 % was obtained on the training and test datasets, respectively. The precision and robustness of the developed models would be of significant interest in determining the concentration of radon (222Rn) activity concentration in the atmosphere for various physical applications especially in regions where field measuring equipment for radon is not available or measurements have been interrupted.

Aerogeophysical characterization of an active subglacial lake system in the David Glacier catchment, Antarctica

In the 2016–2017 austral summer, the University of Texas Institute for Geophysics (UTIG) and the Korea Polar Research Institute (KOPRI) collaborated to perform a helicopter-based radar and laser altimeter survey of lower David Glacier with the goals of characterizing the subglacial water distribution that supports a system of active subglacial lakes and informing the site selection for a potential subglacial access drilling project. This survey overlaps with and expands upon an earlier survey of the Drygalski Ice Tongue and the David Glacier grounding zone from 2011 and 2012 to create a 5 km resolution survey extending 200 km upstream from the grounding zone. The surveyed region covers two active subglacial lakes and includes reflights of ICESat ground tracks that extend the surface elevation record in the region. This is one of the most extensive aerogeophysical surveys of an active lake system and provides higher-resolution boundary conditions and basal characterizations that will enable process studies of these features. This paper introduces a new helicopter-mounted ice-penetrating radar and laser altimetry system, notes a discrepancy between the original surface-elevation-derived lake outlines and locations of possible water collection based on basal geometry and hydraulic potential, and presents radar-based observations of basal conditions that are inconsistent with large collections of ponded water despite laser altimetry showing that the hypothesized active lakes are at a highstand.

Aerogeophysical characterization of an active subglacial lake system in the David Glacier catchment, Antarctica

In the 2016–2017 austral summer, the University of Texas Institute for Geophysics (UTIG) and the Korea Polar Research Institute (KOPRI) collaborated to perform a helicopter-based radar and laser altimeter survey of lower David Glacier with the goals of characterizing the subglacial water distribution that supports a system of active subglacial lakes and informing the site selection for a potential subglacial access drilling project. This survey overlaps with and expands upon an earlier survey of the Drygalski Ice Tongue and the David Glacier grounding zone from 2011 and 2012 to create a 5 km resolution survey extending 200 km upstream from the grounding zone. The surveyed region covers two active subglacial lakes and includes re-flights of ICESat ground tracks that extend the surface elevation record in the region. While this is not the first aerogeophysical survey of an active lake system, it is one of the most extensive, and provides higher resolution boundary conditions and basal characterizations that will enable process studies of these features. This paper introduces a new helicopter-mounted ice-penetrating radar and laser altimetry system; notes a discrepancy between the original surface-elevation-derived lake outlines and locations of possible water collection based on basal geometry and hydraulic potential; and presents radar- based observations of basal conditions that are inconsistent with large collections of ponded water, despite laser altimetry showing that the hypothesized active lakes are at a high-stand.

Problems of the Soviet Arctic Development in the Works by Anglo-American Researchers of the 1930s-1950s

The paper objective is to analyze the works by the Anglo-American researchers (T.A. Taracouzio, T. Armstrong, C.J. Webster et al.) published in the 1930s–1950s, and to estimate their contribution to the study of the early stage of the Soviet Arctic development. These works by Western scholars are of interest to the contemporary researchers not only because they show how the ups and downs of the Soviet policy towards the Arctic were perceived and evaluated in other countries. Some conclusions drawn in the works under consideration remain relevant nowadays, such as the idea that it is impossible to address the problems of the Arctic region effectively without meaningful international cooperation. The Anglo-American specialists used a vast amount of documentary sources and research literature (for the most part, published in Russian) and covered a wide range of issues related to this topic. These issues include the history of scientific exploration; the system of governance in the Arctic in the 1920s-1950s; the economic development; the policy towards the indigenous population etc. While admitting the outstanding accomplishments of the Soviet explorers of the Arctic region, the Western authors also pointed out that there was certain continuity between the pre-revolutionary and Soviet policies implemented in the Arctic; stressed the military and strategic significance of the Arctic territories and negative human impact on the Arctic environment. Specialized scientific research centers contributed to the comprehensive study of the topic. Among such centers one should mention the Scott Polar Research Institute (Cambridge) and the Arctic Institute of North America, which prepared and published 16 volumes of «Arctic bibliography». The author concludes that the Anglo-American researchers laid a foundation for the further study of the problems related to the development of the Arctic zone of the USSR and Russian Federation.

Is there anything natural about the polar?

Are similarities of temperature, snow and ice cover, and (certain) marine mammals sufficient to warrant both polar regions being considered a single object of study or governance? We argue that their treatment as a unit is an invitation to examine the motivations behind the choice to be polar rather than Arctic or Antarctic. For individuals such as James Clerk Ross or Roald Amundsen, logistical requirements and analogous goals facilitated careers spanning both the Arctic and the Antarctic. This trend continued through the 20th century as individual scientists studying phenomena such as glaciers, sea ice, or aurora defined their research as “polar” in nature. Organisations such as the Scott Polar Research Institute and Norwegian Polar Institute could draw on traditions of national exploration in both polar regions, while the Arctic and Antarctic Research Institute in St. Petersburg gained its southern mandate with the importance of the International Geophysical Year. By comparison, neither the Arctic Institute in Copenhagen nor the Argentine Antarctic Institute felt any need to become polar. The creation of polar identity is ultimately a matter of geopolitics, of the value states see in instruments and symbols that speak to polar rather than Arctic or Antarctic interests. In cases such as Finland’s icebreaker industry, a technological capability justified Antarctic interest even without any national research tradition. We conclude by asking whether there is anything more natural about the polar regions than there is about the concept of a “tripolar” world in which the high alpine regions form a natural unit along with the Arctic and Antarctic.

Single Grain (U-Th)/He Ages from EET14074, an Acapulcoite Meteorite

EET14074 is a member of the acapulcoite-lodranite family of meteorites and was discovered in Antarctica in 2014 by the Korean Polar Research Institute (KOPRI). Herein, we obtained (U-Th)/He ages from 20 phosphate aggregates in EET14074 to constrain the sample’s thermal history. The ages range between 116.8 Ma ± 145.7 Ma (1σ) and 4211.5 Ma ± 1089.1 Ma, with an average of 2530 ± 260 Ma (n=20). Excluding outlier ages with large uncertainties, the 13 most concentrated ages yielded a theoretical minimum age of 3000 ± 150 Ma. This age corresponds to a fraction helium loss (f) of ~31% assuming crystallization age of ~4.55 Ga. The uranium abundances in single aliquots are in the range of 1.52 - 289.93 fmol, with an average of 58.00 fmol (n = 20), whereas the thorium abundance ranges between 2.51 and 2337.06 fmol with an average of 1149.29 fmol (n = 20). To explain the observed He loss, thermal diffusion modeling was performed with an assumption that the He loss occurred during a recent passage of the meteorite in Earth’s atmosphere. For the most likely t-T condition of compressional heating in Earth’s atmosphere of this meteorite (T = ~430 ˚C, t = ~10 sec), a fractional loss of 29.3% was calculated when the diffusion domain radius (r) of 92.8 µm was assumed. This estimation is nearly indistinguishable from the observed fractional loss of 31.3%. Additionally, diffusion modeling for another set of data with a different size (r = 40.4 µm) yielded a very similar fractional loss. Therefore, the observed (U-Th)/He age distribution is likely derived from compressional heating during the passage of EET14074 in Earth’s atmosphere.

Survey stories in the history of British polar exploration: museums, objects and people

This essay considers the two institutions that, between them, contain the most significant collections relating to British polar exploration in the UK: the Scott Polar Research Institute and the National Maritime Museum. A discussion of the differences between the two institutions, from their foundations to the substance of their collections, is followed by an indication of their similarities—particularly relating to the interpretation of the objects of exploration in museums, including artefacts of science and surveying. Histories of exploration, particularly in the polar regions, have been dominated by stories of individual sacrifice and achievement. This is despite the origins of many of the expeditions being rooted in scientific goals. This paper considers the role of survey stories within narratives of exploration, and the challenges that curators face in presenting them to audiences who continue to be drawn in by stories of well-known figures such as Scott and Amundsen.

The First Fixed-wing Aircraft for Chinese Antarctic Expeditions: Airframe, modifications, Scientific Instrumentation and Applications

The Antarctic Ice Sheet plays a critical role in global climate and sea level change resulting in it being the focus of international scientific exploration. Airborne platforms have been applied to study large geographical regions of Antarctica that are logistically difficult to reach by other means. For 30 years Chinese Antarctic expeditions, have widely applied ground based platforms in Antarctica. During the 32nd Chinese National Antarctic Research Expedition (years 2015/16), the first fixed-wing aircraft (Snow Eagle 601) was deployed by Polar Research Institute of China with special modifications for polar operation and airborne geophysical investigation of ice sheets. Here, the airframe of the aircraft and modifications for science operation in Polar Regions, as well as scientific instrumentation, system integration and its first application in Antarctica are introduced in detail. [Figure: see text]