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A geodynamic model of the modern Earth was constructed based on the SMEAN 2 global seismic tomography model. Considering the distribution of mantle temperature anomalies in this model, the numerical simulation of a three-dimensional flow of a viscous mantle was carried out taking into account the dependence of the viscosity on temperature and depth in the spherical Earth. The Stokes equation was solved by the finite element method using the CitcomS code. The obtained data on the distribution of the temperature anomalies, dynamic topography, and velocity field in the mantle were used to analyze structural features and geodynamics in the West Antarctic region, as well as the anomalous acceleration of glacier movement and destruction in this area. In particular, the existence and current activity of the West Antarctic Rift System including one of the largest volcanic provinces on the Earth were explained. This explanation was consistent with the measurement data on increased heat flow on the surface. The increased heat flow and volcanic activity in this region lead to instability and accelerated runoff of the West Antarctic ice sheets into the ocean, thus posing the potential threat of a substantial rise in the global sea level. [ABSTRACT FROM AUTHOR]

By combing the characteristics of drilling in Antarctic region, performance requirements on drilling fluid for Antarctic low temperature conditions, and research progress of low temperature drilling fluid, current problems of the drilling fluid have been sorted out, and the development direction of the drilling fluid has been pointed out. Drilling in the Antarctic region mainly includes drilling in snow, ice and subglacial rock formations, and drilling in Antarctic low temperature conditions will face problems in four aspects: (1) low temperature and large temperature changes in the drilling area; (2) likely well leakage and drillstring-sticking in the snow layer, creep in the ice layer, ice chip gathering jamming in the warm ice layer, well wall collapse in the subglacial rock formations; (3) lack of infrastructure and difficulty in logistical support; (4) fragile environment and low carrying capacity. After years of development, progresses have been made on low-temperature drilling fluids for the Antarctic region. Low-temperature petroleum-based drilling fluid, ethanol/ethylene glycol-based drilling fluid, ester-based drilling fluid and silicone oil-based drilling fluid have been developed. However, these drilling fluids have problems such as insufficient low-temperature tolerance, low environmental performance and weak wellbore stability, etc. In order to meet the performance requirements of drilling fluid under low-temperature conditions in Antarctic region, the working mechanisms of low-temperature drilling fluid must be examined in depth; environment-friendly low-temperature base fluid of drilling fluid and related additives must be developed to prepare environmentally friendly low temperature drilling fluid systems; multi-functional integrated adjustment method for drilling fluid must be worked out to ensure well wall stability and improve cutting-carry capacity when drilling ice formations and ice-rock interlayers; and on-site support operation codes must be established to provide technical support for Antarctic drilling.

The paper presents an analysis of polar ecological policy actors. From this perspective, authors discuss in detail a role of state in conservation and development of marine and coastal ecosystems. Furthermore, they describe a green agenda for polar regions. At last, some ways for creating of ecological policies in the Arctic and the Antarctic regions, most especially on behalf of sea and marginal ecosystems conservation and evolution, are proposed. One of the most vital parts of such policies is staff training. The authors have attempted a comprehensive analysis of the Green Agenda at the global, national and local levels in terms of the effectiveness of its proposed mechanisms for the protection of biodiversity in polar areas. Researchers have also reviewed plans of Russia according to the new set of strategies for Arctic and Antarctic regions, which were adopted in 2020. The ideas proposed by the authors can be used in a real-case scenario both for strategies implementation and for public discussion on the global ecological problems.

SOM stabilization rates were estimated in the soils of Antarctic region in case of influence of ornithogenic factor. Soils in large penguin clusters, near nests of Stercorarius sp., as well as soils located in geochemically subordinate positions (also often are visited by birds) were found to be characterized by an increased content of carbon and nitrogen with a rather narrow ratio of C/N. The pH values decreased in ornithogenic soils due to the organic acids that produced plants (mosses, Deschampsia antarctica) inhabit these soils and the decomposition products of the organic matter guano. The amount of CO2, in general, released over the entire experiment period is quite large for both ornithogenic and non-ornithogenic soils. CO2 emission rates were the highest in ornithogenic soils. Ornithogenic soils of the studied area are characterized by the most stabilized organic matter. Thus, the avifauna favors and increases the rate of the mineralization process by several times. An acceleration in the organic matter mineralization rate leads to an increase in nutrients amount available to plants, as in the case of the studied soils. The quality of initial SOM is of a great importance in post-ornithogenic environments. Therefore, further researches of CO2 emissions rates are needed to characterize post-ornithogenic dynamics and develop an approach to model this process.

Background: Ice-free areas in the Antarctic region are strongly limited. The presence of marine mammals and birds in those areas influence soil properties and vegetation composition. Studies on the terrestrial diatom flora in soils influenced by sea birds in the Maritime Antarctic region are scarce. Methods: Samples were collected from two transects on the western shore of the Admiralty Bay region. Light and scanning electron microscopic observations and statistical analyses were conducted to consider the impact of penguin rookeries on soil diatom assemblages. Results: The disturbance associated with the presence of penguin rookeries clearly influences the soil diatom diversity. Assemblages from areas with the highest nutrient input were characterized by a much lower diversity with only few species dominating the flora. One of recorded taxa could not be assigned to any of the known species. Therefore, based on the combination of morphological features analyzed using light and scanning electron microscopes and comparison with similar taxa in the Antarctic region and worldwide, the species is described hereby as new to science-Luticola kaweckae sp.nov. The new species is characteristic for soil habitats with strong penguin influence. [ABSTRACT FROM AUTHOR]

Background Ice-free areas in the Antarctic region are strongly limited. The presence of marine mammals and birds in those areas influence soil properties and vegetation composition. Studies on the terrestrial diatom flora in soils influenced by sea birds in the Maritime Antarctic region are scarce. Methods Samples were collected from two transects on the western shore of the Admiralty Bay region. Light and scanning electron microscopic observations and statistical analyses were conducted to consider the impact of penguin rookeries on soil diatom assemblages. Results The disturbance associated with the presence of penguin rookeries clearly influences the soil diatom diversity. Assemblages from areas with the highest nutrient input were characterized by a much lower diversity with only few species dominating the flora. One of recorded taxa could not be assigned to any of the known species. Therefore, based on the combination of morphological features analyzed using light and scanning electron microscopes and comparison with similar taxa in the Antarctic region and worldwide, the species is described hereby as new to science–Luticola kaweckae sp.nov. The new species is characteristic for soil habitats with strong penguin influence.

Антарктичний регіон характеризується великою різноманітністю видів тварин. Ті з них, яких можна використати для отримання біологічно активних речовин і подальшого створення фармакологічних препаратів, становлять для практичної біотехнології певний інтерес. Тканини тварин Антарктичного регіону посідають широкий спектр білків та пептидів. Молекули білкової природи з механізмами направленої дії, тобто з ферментами різної специфічності, особливо цікавлять дослідників. У даній статті описано розробку і застосування методичних підходів для отримання та подальшої роботи з білковими молекулами й пептидами тканин морських гідробіонтів Антарктичного регіону.

The moss-inhabiting diatom flora has been surveyed for the first time on the Galindez Island, Argentine Islands, the maritime Antarctica. Altogether, 23 diatom taxa belonging to 9 genera were identified. Diatom taxa distribution exhibited considerable variability across the samples and lower species richness compared to the communities surveyed in other Antarctic regions studied earlier - South Shetland Islands and James Ross Island. A pronounced single-species dominance was revealed by the analysis of moss-inhabiting diatom communities’ structure at the majority of moss substrates. The allocation of certain diatom species to the particular moss substrates was detected alongside their complete absence in some samples. The reasons for such moss-inhabiting diatom communities’ variability should be further investigated in follow-up studies. [ABSTRACT FROM AUTHOR]

Objectives of the study is to monitor the modern national scientific literature on Antarctic research, first of all, as an element of systematic information and bibliographic as well as scientometric support for the implementation of state scientific and technical programs. Methods: bibliographic search, scientometric analysis, bibliometric analysis, webometric analysis, and expert analysis. Ukrainian scientific journals, collections of scientific works and reference editions, scientific reports on projects for the implementation of the State Special-Purpose Research Program in Antarctica for 2011—2020, as well as national (“Scientific Ukraine”, “Bibliometryka of Ukrainian Science”, “Scientific Periodicals of Ukraine”, etc.) and foreign bibliographic databases (Scopus, Google Scholar, e-Library, and others.) were used as the main information source for compiling the bibliography. Results: The article presents the results of a bibliographic search and scientometric analysis of the scientific works of Ukrainian scholars and professionals, published in domestic and foreign editions, as well as in materials of international bodies of the Antarctic Treaty system in 2016—2018. The bibliographic descriptions of 353 publications, the most of which are articles in periodicals (143 descriptions) as well as conference and symposia proceedings (162 descriptions), are given. The bibliometric analysis of the data obtained reveals a stable strong dynamics of the publication activity of Ukrainian researchers and their significant contribution to the world researches of Antarctica. There is a noticeable increase in the number of publications in domestic and foreign scientific editions that are indexed in the bibliographic database Scopus. According to the portal of Scientific Periodicals of Ukraine of the Vernadsky National Library of Ukraine of the NAS of Ukraine the level of relevance of publications in the Ukrainian Antarctic Journal (2007—2017) is defined. It is revealed that the bibliographic and scientometric articles are included in the top-groups of publications in the journal and have a positive trend of users demand. Conclusions: the list of current bibliography presented in the article complements and continues the bibliography of domestic publications for 2007—2015, which was submitted in previous issues of the Ukrainian Antarctic Journal (in 2009, 2010, 2012, and 2016). The bibliographic descriptions given create a factual basis for the scientometric and expert analysis of development trends and research results of domestic scientists and specialists as well as determination of the contribution of Ukraine to modern Antarctic research. The data obtained indicates the expediency of further implementation of bibliographic support of the State research programs of Ukraine in Antarctica as well as a regular publication of the current and retrospective national Antarctic scientific bibliography.

SOM stabilization rates were estimated in the soils of Antarctic region in case of influence of ornithogenic factor. Soils in large penguin clusters, near nests of Stercorarius sp., as well as soils located in geochemically subordinate positions (also often are visited by birds) were found to be characterized by an increased content of carbon and nitrogen with a rather narrow ratio of C/N. The pH values decreased in ornithogenic soils due to the organic acids that produced plants (mosses, Deschampsia antarctica) inhabit these soils and the decomposition products of the organic matter guano. The amount of CO2, in general, released over the entire experiment period is quite large for both ornithogenic and non-ornithogenic soils. CO2 emission rates were the highest in ornithogenic soils. Ornithogenic soils of the studied area are characterized by the most stabilized organic matter. Thus, the avifauna favors and increases the rate of the mineralization process by several times. An acceleration in the organic matter mineralization rate leads to an increase in nutrients amount available to plants, as in the case of the studied soils. The quality of initial SOM is of a great importance in post-ornithogenic environments. Therefore, further researches of CO2 emissions rates are needed to characterize post-ornithogenic dynamics and develop an approach to model this process. [ABSTRACT FROM AUTHOR]

Continental Antarctica is a polar desert containing sparse pockets of vegetation within ice-free areas. Despite the recognized association between lichens, mosses and epiphytic diatoms, the environmental factors controlling diatom community structure are poorly understood. We investigated the association between diatom communities and host vegetation characteristics by experimentally adding nutrients and/or water to two bryophyte (healthy and moribund) and two lichen (crustose and Usnea) vegetation types in the Windmill Islands. Diatom communities were morphologically characterized, diversity indices calculated and differences between treatments, vegetation type and vegetation characteristics tested. We identified 49 diatom taxa, 8 of which occurred with > 1% relative abundance. Bryophyte and lichen vegetation harboured significantly different diatom communities, both in composition and diversity indices. Specifically, Luticola muticopsis was more prevalent in moribund bryophytes and crustose lichens, and Usnea lichens showed lower species richness than other types. While nutrient and water additions did not significantly alter diatom communities, diversity indices and some species showed relationships with vegetation physiological characteristics, notably %N and δ13C, suggesting the importance of ambient gradients in water and nutrient availability. Collectively, this work suggests that future conditions favouring the dominance of a particular vegetation type may have a homogenizing effect on the terrestrial diatom communities of East Antarctica. [ABSTRACT FROM AUTHOR]

Оbjectives of the study: to create a bibliography of scientific works of Ukrainian scientists and specialists on Antarctic research for the period 2007–2017. Bibliographic support and scientometric monitoring of the implementation of the State Special-Purpose Research Program in Antarctica for 2011–2020. Promoting the dissemination of scientific, popular scientific as well as other information about the activities of Ukraine in the Antarctic region of the planet. Methods: bibliographic search, scientometric analysis, bibliometric analysis, expert analysis, webometric analysis. Results: bibliographic descriptions and results of the bibliometric analysis of the compiled bibliography of academic papers of Ukrainian researchers on the problems of Antarctic research published in domestic and foreign publications as well as materials of international bodies of the Antarctic Treaty System from January 2016 to December 2017 are given. Conclusions: the data presented indicate a stable positive trend in the development of Ukraine’s research in the Antarcticа and the considerable contribution of domestic scientists and specialists to the world studies of the Antarctic region.

Antarctic krill (Euphausia superba) is a key resource in the Antarctic region, as it is the primary food source for fish, whales, seals, flying birds, penguins and cephalopods. The high concentrations of the species and its possible uses -food for human and animal consumption and in the production of industrial, pharmaceutical and dietetic products-generates interest in the fishing industry. Its relevance motivated the implementation of administrative measures and international regulations for this fishery, which are summarized in this review. Chile is the only South American fishing country that has shown interest in participating in Antarctic krill fishery. Thus, between 1983 and 1994, the Fisheries Development Institute and some companies carried out fishing activities mainly aimed at prospecting and researching this species. However, starting in 2011, the factory trawler FV Betanzos began sustained commercial krill fishing aimed at krill meal production. This document analyzes the information collected by said vessel between 2011 and 2016, including areas of operation, fishing depth catches and CPUE obtained. Also, the main challenges faced by this fishery and the actions planned as solutions are assessed. [ABSTRACT FROM AUTHOR]

Quantification of suspended particulate matter (SPM) measurements—together with statistical tools, polar contour maps and backward air mass trajectory analyses—were implemented to better understand the main local and remote sources of contamination in this pristine region. Field campaigns were carried out during the austral summer of 2016–2017 at the “Gabriel de Castilla” Spanish Antarctic Research Station, located on Deception Island (South Shetland Islands, Antarctic). Aerosols were deposited in an air filter through a low-volume sampler and chemically analysed using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) and Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES). Elements such as Al, Ca, Fe, K, Mg, Na, P, S, Cu, Pb, Sr, Ti, Zn, Hf, Zr, V, As, Ti, Mn, Sn and Cr were identified. The statistical tools together with their correlations (Sr/Na, Al/Ti, Al/Mn, Al/Sr, Al/Pb, K/P) suggest a potentially significant role of terrestrial inputs for Al, Ti, Mn, Sr and Pb; marine environments for Sr and Na; and biological inputs for K and P. Polar contour graphical maps allowed reproducing wind maps, revealing the biological local distribution of K and P (penguin colony). Additionally, backward trajectory analysis confirmed previous affirmations and atmospheric air masses following the Antarctic circumpolar pattern.

The aim of this study was to investigate the fungal community associated with fruits and vegetables transported into the Antarctic region and observe qualitative changes of their surface mycobiota after UV-C treatment. This measure is used to prevent the post-harvest diseases of stored fruits and vegetables and reduce the risk of introducing non-native species to the Antarctic environment. In total, 82 strains of filamentous fungi were isolated from the surfaces of 64 pieces of fresh fruits and vegetables before and after their UV-C treatment. They were assigned to the genera Penicillium, Fusarium, Mucor, Cladosporium, and Acremonium. After the UV-C treatment of the examined fruits and vegetables, spores of the genera Fusarium, Cladosporium and Acremonium were not detected, while spores of the genera Penicillium and Mucor were more resistant and stayed viable after the treatment. Penicillium strains prevailed in the examined samples. Their introduction to the Antarctic environment could represent a potential risk for endemic autochthonous organisms. [ABSTRACT FROM AUTHOR]

Poa annua is a cosmopolitan weed in turf grass. It is a widespread non-native species in the subantarctic and also occurs in the Antarctic Peninsula. It has highly variable morphology, longevity and reproductive capacity across both its invaded and native range. Little is known about the ecology of P. annua in the subantarctic, particularly its longevity, morphological variation across small spatial scales and competitive ability. We monitored individual P. annua plants on subantarctic Macquarie Island to assess their longevity; quantified morphology and biomass allocation across environmental gradients; and assessed community diversity indices in areas of varying P. annua density. We show that P. annua plants on Macquarie Island are perennial, and their morphology varies with elevation, animal disturbance and soil properties. At low altitude, coastal sites with high animal disturbance and deep, sandy soils, P. annua plants are larger and native plant diversity is low. Conversely, at high altitude sites P. annua plants are smaller and the diversity of native species is not reduced. This new information informs why P. annua is the most successful plant invader in the subantarctic and quantifies some key characteristics enabling an invasive species to function well beyond its natural range. Community ecology theory can also explain patterns in the ecology of P. annua on Macquarie Island. [ABSTRACT FROM AUTHOR]

The increase of anthropogenic activities and growth of technology in Antarctica is fuelled by the high demand for petroleum hydrocarbons needed for daily activities. Oil and fuel spills that occur during explorations have caused hydrocarbon pollution in this region, prompting concern for the environment by polar communities and the larger world community. Crude oil and petroleum hydrocarbon products contain a wide variety of lethal components with high toxicity and low biodegradability. Hydrocarbon persistence in the Antarctic environment only worsens the issues stemming from environmental pollution as they can be long-term. Numerous efforts to lower the contamination level caused by these pollutants have been conducted mainly in bioremediation, an economical and degrading-wise method. Bioremediation mainly functions on conversion of complex toxic compounds to simpler organic compounds due to the consumption of hydrocarbons by microorganisms as their energy source. This review presents a summary of the collective understanding on bioremediation of petroleum hydrocarbons by microorganisms indigenous to the Antarctic region from past decades to current knowledge. [ABSTRACT FROM AUTHOR]

The aim of this work was to study the oxidative profile of gills of two limpet species (Nacella (Patinigera) magellanica and Nacella (Patinigera) deaurata) (Gmelin, 1971) exposed to different environmental conditions. Due to the tidal characteristics of the Beagle Channel, N. magellanica are exposed to air twice daily for 3 to 5 hours each time, whereas N. deaurata are exposed to air for 3 hours only during spring tides. The different regime of exposure includes extreme temperatures under 0ºC during winter and more than 20°C in summer for N. magellanica, whereas N. deaurata are usually covered by more than 0.3 m of water at 4°C in winter and 11°C in summer. No significant differences were found between the two molluscs regarding the oxygen uptake, the content of ?-tocopherol and ?-carotene and the activities of the antioxidant enzymes catalase and superoxide dismutase. Lipid peroxidation in gills was estimated as the content of lipid radicals, assessed by electron paramagnetic resonance (EPR). Lipid radical content and total iron content were respectively 80.6 and 62% lower in N. magellanica than in N. deaurata. A typical EPR spectrum of ascorbyl radical in gills from both limpets was observed. Both the ascorbyl radical content and the ascorbyl radical content/ascorbate content ratio were significantly lower in N. magellanica than in N. deaurata. In the Antarctic Nacella concinna inhabits all levels of the littoral zone. Limpets at the highest level in the intertidal showed significantly increased activities of both catalase and superoxide dismutase as compared to their intertidal and subtidal relatives. Thus, it seems that Antarctic high intertidal conditions, involving regular exposure to air and presumably also thermal stress on sunny days during the Antarctic summer, cause a necessity for N. concinna to ward off higher oxygen radical species production by increasing its antioxidant defence. Taken as a whole, the data presented here indicate that coping with environmentally demanding conditions requires a complex adjustment of the physiological metabolic pathways to ensure survival by minimising intracellular damage.

Saccharide compounds can distinguish the influence of both biogenic emissions and anthropogenic sources. In this study, the spatial distribution of 10 saccharide compounds was observed to determine the major factor for the production of organic aerosols in the pristine marine regions from the North Pacific Ocean to the Antarctic Ocean. The pristine marine atmospheric PM 2.5 (Particle matter with an aerodynamic diameter equal to or less than nominal 2.5 μm) samples were collected using a high-volume air sampler connected to a wind sector controller installed in the Korean Ice-breaking Research Vessel (IBRV) during the cruise through the Pacific Ocean: from the Yellow Sea, Korea on October 31, 2018 to the Antarctic Ocean on December 14, 2018. In the pristine marine region, the total saccharides concentrations varied greatly from 0.16 to 16.57 ng/m3 (mean: 3.02 ± 4.76 ng/m3). The compositions of 10 saccharide compounds in each PM 2.5 sample changed when the marine geographic characteristics changed. The contribution of levoglucosan in the sample collected near land was higher than the sample collected in the open ocean. In addition, saccharides concentrations had a strong positive correlation with OC (Organic carbon), indicating that the increase of saccharides concentrations strongly contributes to the increase in OC concentration in the pristine marine region. The highest concentration of saccharides was observed near the New Zealand coast, which also showed highest air mass exposure to marine biology. We also found that the spatial distribution of saccharide composition was correlated with the spatial distribution of phytoplankton. From these observations, we concluded that 1) marine phytoplankton can be a significant source of organic aerosol production and 2) the type of phytoplankton in a region affects the change of saccharides composition in PM 2.5. • The composition of 10 saccharide compounds in each PM 2.5 sample changed according to the marine geographic characteristics. • The increase in saccharides concentrations contributes to the increase in OC concentration in the pristine marine region. • The composition of saccharides was possibly linked to the phytoplankton taxonomic composition in the pristine marine regions. [ABSTRACT FROM AUTHOR]

Four taxa belonging to the complex of species around Achnanthidium minutissimum were found during the ongoing taxonomic revision of the Antarctic freshwater and limno-terrestrial diatom flora. Two taxa were previously described as Achnanthidium lailae and A. sieminskae. Two others were formerly identified as A. minutissimum but detailed light and scanning electron microscopical observations revealed sufficient morphological differences compared to the type of A. minutissimum, to justify their separation and description as new taxa: Achnanthidium indistinctum and A. maritimo-antarcticum. The morphology and ecology of all four taxa are discussed comparing the species with morphologically similar taxa. The biogeographical consequences of the splitting of the former A. minutissimum complex in the Antarctic Region are discussed.

The biogeographical distribution of the benthic hydroid species collected during the Spanish Antarctic expedition Antártida 8611 has been studied. An inventory of the Antarctic and Magellan benthic thecate hydroid faunas, along with a comparison between the two, have been also carried out. 104 and 126 species of thecate hydroids have been considered in the Antarctic and Magellan areas, respectively. 72 species (69%) of the Antarctic species and 49 (39%) of the Magellan species are endemic. 23 species are present both in the Antarctic Region and in the Magellan area, representing 22% and 18% respectively, and indicating an important relationship between both faunas.

Air quality is a global concerning topic because of its great impact on the environment and health. Because of that, the study of atmospheric aerosols looking for harmful pollutants is rising, as well as the interest in the origin of the contaminants. Depending on the nature and size of the aerosols, some elements can be detected at a great distance from the emission source, even in Antarctica, where this study is conducted. Several samples of PM filters from 2018 to 2019 (Deception Island) and 2019–2020 (Livingston Island) campaigns have been analyzed by three powerful spectroscopic techniques: FESEM (Field Emission Scanning Electron Microscopy), LIBS (Laser Induced Breakdown Spectroscopy), and ICP-MS (Inductively Coupled Plasma Mass Spectrometry). These techniques have allowed us to find some heavy metals in the air of the Antarctic region (Al, Fe, Ti, Ni, Cr, and Mn). Deeper studies on ICP-MS results have confirmed those results and have also provided information on their potential sources. Thus, while Al, Fe, Ti and Mn concentrations can be explained by crustal origin, Ni and Cr presented high values only coherent with important human contribution. The results point out that the Antarctic region is no longer a clean and isolated environment from human pollution. [Display omitted] • Antarctic atmospheric aerosols PM10 were analyzed by FESEM, LIBS and ICP-MS. • All techniques showed great concentrations of crustal elements such as Fe, Al and Ti. • Enrichment factors and correlations studies were performed pointing out an important human contribution of Ni and Cr. [ABSTRACT FROM AUTHOR]

Polar sea ice is an important input to global climate models and is considered to be a sensitive indicator of climate change. While originally designed only for wind estimation, radar backscatter measurements collected by wind scatterometers have proven useful for estimating the extent of sea ice. During the Quick Scatterometer (QuikSCAT) mission, SeaWinds data were used to operationally map the sea ice extent. The resulting sea ice maps were used to mask near-surface winds to support SeaWinds' primary mission of measuring near-surface winds over the ocean. This paper describes the operational SeaWinds sea ice extent mapping algorithm, provides validation comparisons, and presents results from the ten-year data product. Starting with enhanced resolution horizontal polarization and vertical polarization backscatter images, the algorithm employs an iterative maximum-likelihood classifier with fixed thresholds to segment sea ice and open ocean pixels. Residual classification errors are reduced through binary image processing techniques and sea ice growth/retreat constraint methods. The algorithm results are compared with sea ice concentrations derived from Special Sensor Microwave/Imager data and with RADARSAT synthetic aperture radar imagery. The results suggest differences in the sensitivities of active and passive products given their channel sets and specific algorithms. Derived sea ice extents over the full decade-long QuikSCAT mission data set are analyzed to show important trends in sea ice extent for the Antarctic and Arctic regions. [ABSTRACT FROM PUBLISHER]

Quantification of suspended particulate matter (SPM) measurements—together with statistical tools, polar contour maps and backward air mass trajectory analyses—were implemented to better understand the main local and remote sources of contamination in this pristine region. Field campaigns were carried out during the austral summer of 2016–2017 at the "Gabriel de Castilla" Spanish Antarctic Research Station, located on Deception Island (South Shetland Islands, Antarctic). Aerosols were deposited in an air filter through a low-volume sampler and chemically analysed using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) and Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES). Elements such as Al, Ca, Fe, K, Mg, Na, P, S, Cu, Pb, Sr, Ti, Zn, Hf, Zr, V, As, Ti, Mn, Sn and Cr were identified. The statistical tools together with their correlations (Sr/Na, Al/Ti, Al/Mn, Al/Sr, Al/Pb, K/P) suggest a potentially significant role of terrestrial inputs for Al, Ti, Mn, Sr and Pb; marine environments for Sr and Na; and biological inputs for K and P. Polar contour graphical maps allowed reproducing wind maps, revealing the biological local distribution of K and P (penguin colony). Additionally, backward trajectory analysis confirmed previous affirmations and atmospheric air masses following the Antarctic circumpolar pattern. [ABSTRACT FROM AUTHOR]

É estudada a distribuição geográfica e a variação de caracteres morfológicos de três espécies de ofiuroides (OpiLacantha antartica, Astrotoma agassizzi e Gorgonecephalus chilensis) das regiões Antártica e Subantãrtica. São também apresentadas observações sobre biologia reprodutiva.The geographical distribution and the variation of morphological characters of three (Gorgonecephalus chilensis, Astroma agassizii, Ophiacantha antartica) from the Antarctic and Subantarctic regions are studied. Observations on reproductive biology are presented.