Search

Antarctica is a continent dedicated to 'peace and science' and subject to international consensus-based governance through the Antarctic Treaty System. Through the Treaty, decision-making powers are reserved to Consultative Parties, which are those countries recognized as demonstrating 'substantial scientific research activity' in Antarctica. Türkiye acceded to the Antarctic Treaty in 1996. In its National Polar Science Program (2018–2022) it first declared a desire to attain consultative status to the Treaty. Here, we examine Türkiye's recent development across Antarctic science, policy and logistics. Since 2016, Türkiye's national Antarctic scientific output has increased threefold, ranking seventh amongst the current 27 non-Consultative Parties, and this output is greater than some Consultative Parties. Türkiye has submitted more papers to the Antarctic Treaty Consultative Meetings than any other non-Consultative Party and is actively participating in the development of the Antarctic Protected Area system. To facilitate longer-term research goals, Türkiye is constructing an Antarctic research station (Horseshoe Island, Antarctic Peninsula), has joined several polar organizations, including the Scientific Committee on Antarctic Research (SCAR) and the Council of Managers of National Antarctic Programs (COMNAP), and has developed scientific and logistical collaborations with many established Antarctic nations. The exceptionally rapid growth of Türkiye's Antarctic activities provides a firm foundation for the development of a future application for consultative status. [ABSTRACT FROM AUTHOR]

Featured Application: This work gives indications for cleaning and preservation of ice cores, which will be drilled in Antarctica during the EU project Beyond EPICA Oldest Ice and provides general guidelines for ice drilling activities and preservation of ice cores. To reconstruct climate history of the past 1.5 Million years, the project: Beyond EPICA Oldest Ice (BEOI) will drill about 2700 m of ice core in East Antarctica (2021–2025). As drilling fluid, an aliphatic ester fluid, EstisolTM 140, will be used. Newly drilled ice cores will be retrieved from the drill soaked in fluid, and this fluid should be removed from the cores. Most of it will be vacuum-cleaned off in a Fluid Extraction Device and wiped off with paper towels. Based on our experiences in Greenland deep ice coring, most of the residual fluid can be removed by storing the cores openly on shelves in a ventilated room. After a week of "drying", the cores have a dry feel, handling them do not give "wet" gloves and they can easily be marked with lead pencils. This paper presents a theoretical investigation and some simple testing on the "drying" process. The rates of sublimation of ice and evaporation of fluid have been calculated at different temperatures. The calculations show that sublimation of the ice core should not occur, and that evaporation of fluid should be almost negligible. Our test results support these calculations, but also revealed significant fluid run-off and dripping, resulting in the removal of most of the fluid in a couple of days, independent of temperature and ventilation conditions. Finally, we discuss crucial factors that ensure optimal long-term ice core preservation in storage, such as temperature stability, defrosting cycles of freezers and open core storage versus storage of cores in insulated crates. [ABSTRACT FROM AUTHOR]

Climate models, derived from process understanding, are essential tools in the study of climate change and its wide-ranging impacts on the biosphere. Hindcast and future simulations provide comprehensive spatiotemporal estimates of climatology that are frequently employed within the environmental sciences community, although the output can be afflicted with bias that impedes direct interpretation. Bias correction approaches using observational data aim to address this challenge. However, approaches are typically criticised for not being physically justified and not considering uncertainty in the correction. These aspects are particularly important in cases where observations are sparse, such as for weather station data over Antarctica. This paper attempts to address both of these issues through the development of a novel Bayesian hierarchical model for bias prediction. The model propagates uncertainty robustly and uses latent Gaussian process distributions to capture underlying spatial covariance patterns, partially preserving the covariance structure from the climate model which is based on well-established physical laws. The Bayesian framework can handle complex modelling structures and provides an approach that is flexible and adaptable to specific areas of application, even increasing the scope of the work to data assimilation tasks more generally. Results in this paper are presented for one-dimensional simulated examples for clarity, although the method implementation has been developed to also work on multidimensional data as found in most real applications. Performance under different simulated scenarios is examined, with the method providing most value added over alternative approaches in the case of sparse observations and smooth underlying bias. A major benefit of the model is the robust propagation of uncertainty, which is of key importance to a range of stakeholders, from climate scientists engaged in impact studies, decision makers trying to understand the likelihood of particular scenarios and individuals involved in climate change adaption strategies where accurate risk assessment is required for optimal resource allocation. [ABSTRACT FROM AUTHOR]

The focus of this paper is on COVID-19, the December 2019 dated respiratory epidemic or infection that has ravaged most, if not all, of the world's 253 "countries" (consisting of 194 independent nation-states, 55 dependent-states, Antarctica, and 3 other territories). Readers of this paper should be aware of at least three facts. First, as of January 2022, the submission date of this paper, COVID-19 continues to impact the world, although to a much lesser extent, given the protection afforded by the mRNA vaccines, the boosters, and the antiviral medications (e.g., oseltamivir, penciclovir, acyclovir, Paxlovid, etc.). Second, the paper should be regarded as being inconclusive in both its outlook and its list of references; it provides, at best, an intermediary account of the continuing COVID-19 pandemic. Third, like the Spanish Flu of 1918, it is speculated that the COVID-19 pandemic will not endure beyond three years and will conclude as an endemic problem by, hopefully, early 2023. Therefore, the paper is partitioned into three sections which, respectively, address the infection's three phases: epidemic (initial infection), pandemic (worldwide infection) and endemic (pervasive but nonlife-threatening infection) phases. The lessons learned from the range of decisions made throughout the COVID-19 phases should help to inform and better prepare the world for future pathogens and deadly diseases. [ABSTRACT FROM AUTHOR]

The bryophytes are the second largest group of land plants and are represented by three lineages: Marchantyophyta (liverworts), Anthocerotophyta (hornworts), and Bryophyta (mosses). They occupy a wide variety of habitats, from deserts to Antarctica, and exercise great ecological importance. These facts and their wide use in traditional medicine raise the question of what is known about moss chemistry. This paper gathered studies from the last 52 years about the compounds identified in mosses, aiming to address the following questions: Are mosses chemically under-studied? How many families, genera, and species of mosses have been chemically studied? Which continent and countries have been responsible for the majority of these studies? A literature search was performed in major scientific databases, using a combination of keywords. A total of 199 papers were compiled, of which 45% were published during the last decade. Only a small percentage of moss species has been studied, mostly from Europe and Asia. Dicranales and Hypnales are the most studied orders. In general, fatty acids and flavonoids are the most commonly reported classes of compounds. Biflavonoids and triflavonoids are detected mainly in derived clades of mosses, while coumarins are most reported for basal groups. Akthough only a small percentage of moss species has been chemically studied, most of these studies were published in the last decade—there has been a 135% increase in the number of reported compounds in the last 13 years. The emergence of new equipment, which can produce high-resolution spectra with small amounts of sample, combined with bioinformatics tools, has undoubtedly contributed to the increase of chemical investigation of mosses. Also, advances in the identification and phylogenetics of moss groups are contributing to a better understanding of them generally, which should lead also to increased study of moss chemistry. [ABSTRACT FROM AUTHOR]

A large number of research stations have been established to provide members of Antarctic expeditions with logistical support. A previous study confirmed that the wind and solar energy resources of the Chinese Zhongshan Station, a coastal station located in an area of Lassmann Hills in East Antarctica, are highly synergetic and complementary. Considering the demand for a renewable energy power supply in Zhongshan Station, this paper introduces a hybrid energy system with wind–solar–diesel–battery co-generation used as a power supply scheme. Based on the 2015 climate data for Zhongshan Station, the wind–solar resources, conventional energy system, and annual diesel consumption of the station area were analyzed. The annual electrical load demand of each building in the station area was quantitatively expounded. Compared with the original power supply system, and combined with the analysis results of the thermal load and electrical load demands of the station, an objective function based on the requirements of economy, reliability, and environmental protection was presented. According to the constraint conditions of the heat energy and electrical energy load balance in the station area, a multi-objective scheduling strategy for the system was designed. Finally, the effects of this scheduling strategy were analyzed under three different application scenarios. The results indicated that the annual load demand was significantly lower than before the scheduling, and that a 50% reduction in diesel consumption could be achieved, demonstrating that the multi-objective scheduling strategy proposed in this paper could achieve optimal energy scheduling and management of the renewable hybrid energy system. [ABSTRACT FROM AUTHOR]

In Antarctica, it is extremely difficult to organise medical evacuations in winter. Antarctic physicians are often alone and must be prepared to perform surgery and dentistry, even if they are not specialists. This scoping review summarises epidemiological data on the types of surgical procedures performed in Antarctica and identifies gaps in the literature in this area. We searched PubMed and Google Scholar, without language restriction, for papers published between 1 January 1904, and 1 February 2022. Of the 35 papers on 12 Antarctic programs, very few were retrospective observational epidemiological studies; the majority were medical reports. The search identified 41 surgical procedures or reasons for surgical consultation, 19 different reasons for medical evacuations, and 12 causes of death that may have required surgical management. The diagnostic classifications used and the prevalence of each reported surgical speciality were heterogeneous. The most cited specialities were orthopaedics, dentistry, and digestive surgery. Telemedicine was integrated into on-site care or medical evacuation decisions. The current literature is poor, and most studies do not apply to surgical issues. The heterogeneous data collection methodologies limit their interpretation. A standardised diagnostic classification and detailed and systematic epidemiological registers will help define the contours of surgical management in Antarctica. [ABSTRACT FROM AUTHOR]

The changes implemented in 2005 in the development strategies of Antarctic science carried out by Chile have had a positive impact on the scientific productivity of the Chilean Antarctic Science Program (PROCIEN). We analysed scientometric indicators from between 2009 and 2019. The bibliographic data were extracted from the Web of Science database using search query keywords. We used multiple correspondence analysis to identify specific trends and also network analyses of international collaboration in VOSviewer. The number of Antarctic science publications in Chile has gradually increased from 21 in 2009 to 95 in 2019. The rise in the number of articles was higher in journals for the first impact factor quartile. Research lines showing increased first-quartile impact factor papers corresponded to Antarctic ecosystems, biotechnology and geosciences. The main geographical domains in which such research activities have been carried out corresponded to in the South Shetland Islands and the Antarctic Peninsula. Fieldwork data are the main sources for the production of scientific articles, and there are three science platforms within which most of these papers concentrate. The diversification of funding sources, the implementation of improvements in the selection process and Chile's alignment with Scientific Committee on Antarctic Research programmes have contributed to improving the science that Chile has developed in Antarctica. [ABSTRACT FROM AUTHOR]

Repeated electrical resistivity tomography (ERT) surveys can substantially advance the understanding of spatial and temporal freeze-thaw dynamics in remote regions, such as Antarctica, where the evolution of permafrost has been poorly investigated. To enable the time-lapse ERT surveys in Antarctica, however, an automated ERT (A-ERT) system is required, as regular site visits are not feasible. In this context, we developed a robust A-ERT prototype and installed it in the Crater Lake CALM-S site at Deception Island, Antarctica to collect quasi-continuous ERT measurements. To efficiently process a large number of obtained A-ERT datasets, we developed an automated data processing workflow to efficiently filter and invert the A-ERT datasets and extract the key information required for a detailed investigation of permafrost and active layer dynamics. In this paper, we report on the results of two complete year-round A-ERT datasets collected in 2010 and 2019 at Crater Lake CALM-S site and compare them with available climate and borehole data. The A-ERT profile has a length of 9.5 m with an electrode spacing of 0.5 m, enabling a maximum investigation depth of approximately 2 m. Our detailed investigation of the A-ERT data and inverted modeling results shows that the A-ERT system can detect the active-layer freezing and thawing events with very high temporal resolution. The resistivity of the permafrost zone in 2019 is very similar to the values found in 2010, suggesting the stability of the permafrost over almost one decade at this site. The evolution of thaw depth exhibits also a similar pattern in both years, with the active layer thickness fluctuating between 0.20–0.35 m. However, a slight thinning of the active layer is evident in early 2019, compared to the equivalent period in 2010. These findings show that A-ERT, combined with the new processing workflow that we developed, is an efficient tool for studying permafrost and active layer dynamics with very high resolution and minimal environmental disturbance. The ability of the A-ERT setup to monitor the real-time progression of thaw depth, and to detect brief surficial refreezing and thawing of the active layer reveals the significance of the automatic ERT monitoring system to record continuous resistivity changes. This shows that the A-ERT setup described in this paper can be a significant addition to the Global Terrestrial Network for Permafrost (GTN-P) and the Circumpolar Active Layer Monitoring (CALM) networks to further investigate the impact of fast-changing climate and extreme meteorological events on the upper soil horizons and work towards establishing an early warning system for the consequences of climate change. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to explore possible legal issues concerning the Dronning Maud Land Air Network (DROMLAN) under the Antarctic Treaty system. By examining the recent discussion concerning DROMLAN within the Antarctic Treaty Consultative Meeting (ATCM) and relevant State practice, this paper argues that States parties have difficulty in fully complying with the obligations of advanced notice under Article VII (5) of the Antarctic Treaty and Environmental Impact Assessment under Article VIII (2) of the Madrid Protocol for DROMLAN's operation. Finally, this paper suggests that good communication among relevant States parties and private actors is important for enhancing compliance with these obligations. [ABSTRACT FROM AUTHOR]

This paper documents the occurrence of the genus Umbilicaria in the Argentine Islands–Kyiv Peninsula region of the Graham Coast in the maritime Antarctic. The presence of seven Umbilicaria species (U. africana, U. antarctica, U. aprina, U. decussata, U. kappenii, U. nylanderiana and U. umbilicarioides) in the ice-free areas of the Argentine Islands–Kyiv Peninsula region were confirmed. The species of U. africana and U. aprina are documented from the studied region for the first time. This study moves the southern distribution limit of U. africana about 300 km to the south: to the Argentine Islands–Kyiv Peninsula region. The distribution maps of Umbilicaria species for the studied region and maritime Antarctica are prepared. [ABSTRACT FROM AUTHOR]

Climate change has resulted in more frequent occurrences of extreme events, such as flooding and heavy snowfall, which can have a significant impact on densely populated or industrialised areas. Numerical models are used to simulate and predict these extreme events, enabling informed decision-making and planning to minimise human casualties and to protect costly infrastructure. LISFLOOD is an integrated hydrological model underpinning the European Flood Awareness System and Global Flood Awareness System (EFAS and GloFAS, respectively), developed by the Copernicus Emergency Management Service (CEMS). The CEMS_SurfaceFields_2022 dataset is a new set of high-resolution surface fields at 1 and 3 arcmin resolution (approximately 2 and 6 km at the Equator, respectively) based on a wide variety of high-resolution and up-to-date data sources. The 1 arcmin fields cover Europe, while the surface fields at 3 arcmin cover the global land surface (excluding Antarctica). The dataset encompasses (i) catchment morphology and river networks, (ii) land use, (iii) vegetation cover type and properties, (iv) soil properties, (v) lake information, and (vi) water demand. This paper details the complete workflow used to generate the CEMS_SurfaceFields_2022 fields, including the data sources and methodology. Whilst created together with upgrades to the open source LISFLOOD code, the CEMS_SurfaceFields_2022 fields can be used independently for a wide range of applications, including as input to hydrological, Earth system, or environmental models or for carrying out general analyses across spatial scales, ranging from global and regional levels to local levels (especially useful for regions outside Europe), expected to improve the accuracy, detail and realism of applications. [ABSTRACT FROM AUTHOR]

Climate changes induced by stratospheric ozone depletion over Antarctica have been recognized as an important consequence of the recently observed Southern Hemisphere atmospheric circulation. Here we present evidences that the Brazilian coast (Southwestern Atlantic) may have been impacted from both winds and sea surface temperature changes derived from this process. Skeleton analysis of massive coral species living in shallow waters off Brazil are very sensitive to air-sea interactions, and seem to record this impact. Growth rates of Brazilian corals show a trend reversal that fits the ozone depletion evolution, confirming that ozone impacts are far reaching and potentially affect coastal ecosystems in tropical environments. [ABSTRACT FROM AUTHOR]

This paper aims to solve the limitations of traditional gravity physical property inversion methods such as insufficient depth resolution and difficulties in parameter selection, by proposing an improved 3D gravity inversion method based on deep learning. The deep learning network model is established using the fully convolutional U-net network. To enhance the generalization ability of the sample set, the large-scale training set and test set are generated by the random walk, based on the forward theory. Founded on the traditional loss function's definition, this paper introduces an improvement incorporating a physical constraint to measure the degree of data fitting between the predicted and the real gravity data. This improvement significantly boosted the accuracy of the deep learning inversion method, as verified through both a single model and an intricate combination model. Finally, we applied this improved inversion method to the gravity data from the Gamburtsev Subglacial Mountains in the interior of East Antarctica, obtaining a comprehensive 3D crustal density structure. The results provide new evidence for the presence of a dense crustal root situated beneath the central Gamburtsev Province near the Gamburtsev Suture. [ABSTRACT FROM AUTHOR]

Copyright of Geomatics & Information Science of Wuhan University is the property of Geomatics & Information Science of Wuhan University 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.)

Surface solar radiation (SSR) is an essential factor in the flow of surface energy, enabling accurate capturing of long-term climate change and understanding of the energy balance of Earth's atmosphere system. However, the long-term trend estimation of SSR is subject to significant uncertainties due to the temporal inhomogeneity and the uneven spatial distribution of in situ observations. This paper develops an observational integrated and homogenized global terrestrial (except for Antarctica) station SSR dataset (SSRIH station) by integrating all available SSR observations, including the existing homogenized SSR results. The series is then interpolated in order to obtain a 5 ∘ × 5 ∘ resolution gridded dataset (SSRIH grid). On this basis, we further reconstruct a long-term (1955–2018) global land (except for Antarctica) SSR anomaly dataset with a 5 ∘ × 2.5 ∘ resolution (SSRIH 20CR) by training improved partial convolutional neural network deep-learning methods based on 20th Century Reanalysis version 3 (20CRv3). Based on this, we analysed the global land- (except for Antarctica) and regional-scale SSR trends and spatiotemporal variations. The reconstruction results reflect the distribution of SSR anomalies and have high reliability in filling and reconstructing the missing values. At the global land (except for Antarctica) scale, the decreasing trend of the SSRIH 20CR (- 1.276 ± 0.205 W m -2 per decade) is smaller than the trend of the SSRIH grid (- 1.776 ± 0.230 W m -2 per decade) from 1955 to 1991. The trend of the SSRIH 20CR (0.697 ± 0.359 W m -2 per decade) from 1991 to 2018 is also marginally lower than that of the SSRIH grid (0.851 ± 0.410 W m -2 per decade). At the regional scale, the difference between the SSRIH 20CR and SSRIH grid is more significant in years and areas with insufficient coverage. Asia, Africa, Europe and North America cause the global dimming of the SSRIH 20CR , while Europe and North America drive the global brightening of the SSRIH 20CR. Spatial sampling inadequacies have largely contributed to a bias in the long-term variation of global and regional SSR. This paper's homogenized gridded dataset and the Artificial Intelligence reconstruction gridded dataset (Jiao and Li, 2023) are both available at 10.6084/m9.figshare.21625079.v1. [ABSTRACT FROM AUTHOR]

In January 1964, temperature measurements were made on Lake Joyce, in the Taylor Valley, Antarctica. The lake had a salt concentration gradient that stabilised it against mixing, much like other lakes in the area, but the maximum water temperature was about 0.8°C, much less than the temperature of the other lakes as reported in earlier published papers. [ABSTRACT FROM AUTHOR]

Drawing from an analysis of experiences in outer space law, this paper provides insights into challenges involved with managing the global common spaces of the polar regions. The literature concerning governance of the international commons regions focuses on justice and equity concerning natural resources, climate change, the speed, uncertainty and consequences stemming from key actor activity in the Polar Regions. This usually boils down to successes and failures of treaty noncompliance and enforcement mechanisms, or the lack thereof. This paper highlights a current political process aimed at dismantling agreed upon terms outer space international agreements. This offers a snapshot of a political process, likely to influence evolving polar legal norms for the rapidly melting Arctic and Antarctic regions. This is a conceptual paper borrowing theoretical and methodological approaches from political science and international relations such as a Gramscian analysis, constructivism theory and critical discourse analysis, to present several interesting ideas. The purpose is to enable people to understand and explain that future colonisation patterns are unfolding today. It calls attention to issues likely to challenge and define our world in the twenty-first century. [ABSTRACT FROM AUTHOR]

The meridional overturning circulation (MOC) in the ocean is a key player in the global climate system, while continental topography provides an essential backdrop to the system. In this study, we design a series of coupled model sensitivity experiments to investigate the influence of various mountain ranges on the global thermohaline circulation. The results highlight the influence of the Tibetan Plateau (TP) on the global thermohaline circulation. It emerges as a requisite for establishing the Atlantic MOC (AMOC) and a determining factor for the cessation of the Pacific MOC (PMOC). Additionally, the Antarctic continent plays a vital role in facilitating the TP to form the AMOC. While the formation of the AMOC cannot be attributed to any single mountain range, the TP alone can inhibit the PMOC's development. By modifying the global hydrological cycle, the TP is likely to have been crucial in molding the global thermohaline circulation. This paper presents quantitative evaluation of the role of different continental mountains in shaping the global meridional overturning circulation. The Tibetan Plateau is likely to have been crucial in molding the global thermohaline circulation. [ABSTRACT FROM AUTHOR]

The Ilyarachninae are a diverse and widely distributed subfamily of the asellote family Munnopsidae. This paper describes nine new deep-sea species from two Ilyarachninae genera, Ilyarachna and Notoapais, from the southwestern Pacific, namely from New Zealand and the east coast of Australia. Ilyarachna aculeatus n. sp., Ilyarachna brucei n. sp., Ilyarachna franki n. sp., Ilyarachna mclayi n. sp., Ilyarachna pacifica n. sp., Ilyarachna sami n. sp., Ilyarachna taranui n. sp. and Notopais chathamensis n. sp. are described from New Zealand waters, while Notopais likros n. sp. is described from off the east coast of Australia. Additionally, a redescription of Notopais spinosa from the Balleny Islands, Antarctica, and a revised key to the Ilyarachna and Notopais species from the southwest Pacific are included, and the distribution, affinities, and diagnostic characters of the new species are discussed. [ABSTRACT FROM AUTHOR]

The thickness of the Antarctic ice sheet is a crucial parameter for inferring glacier mass and its evolution process. In the literature, the gravity method has been proven to be one of the effective means for estimating ice sheet thickness. And it is a preferred approach when direct measurements are not available. However, few gravity inversion methods are valid in rugged terrain areas with undulating observation surfaces (UOSs). To solve this problem, this paper proposes an improved high-precision 3D density interface inversion method considering terrain and UOSs simultaneously. The proposed method utilizes airborne gravity data at their flight altitudes, instead of the continued data yield from the unstable downward continuation procedure. In addition, based on the undulating right rectangular prism model, the large reliefs of the terrain are included in the iterative inversion. The proposed method is verified on two synthetic examples and is successfully applied to real data in East Antarctica. [ABSTRACT FROM AUTHOR]

Increasing snow accumulation over the Antarctic Ice Sheet may mitigate future sea level rise. However, current estimates of mitigation potential are poorly constrained due to limited records of past variability. We present an annually resolved reconstruction of Antarctic snow accumulation from 1801 to 2000 CE, employing a paleoclimate data assimilation methodology to integrate ice core records with a multi‐model ensemble of climate simulations. Our reconstruction correlates well with instrumental reanalysis, and we find that Antarctic accumulation rates increased over the 20th‐century, resulting in a modest amount (∼1 mm) of sea level mitigation. Mitigation is primarily driven by an accelerating trend since around 1970. Our results contrast with previous mitigation estimates of ∼10–12 mm; this discrepancy is due to poorly constrained baseline estimates of 19th‐century accumulation in East Antarctica. Our reconstruction suggests that the uncertainty of future sea level mitigation from increasing Antarctic accumulation has been underestimated. Plain Language Summary: Ice loss from Antarctica causes sea level to rise, but Antarctica can also mitigate sea level rise if snowfall on the continent increases faster than the ice loss. There is not currently a consensus on whether Antarctica will contribute to or mitigate sea level rise in the coming century, due to a lack of Antarctic snowfall records. In this paper, we merge information from ice core records with climate models to reconstruct annual Antarctic snowfall from 1801 to 2000. We find that snowfall on Antarctica increased during the 20th‐century, but only had a modest counteracting effect of 1 mm on sea level rise in the 20th‐century, much less than a previous estimate of 10 mm. The large discrepancy is due to uncertainty in East Antarctic accumulation in the 19th‐century. The potential for Antarctica to mitigate sea level is uncertain, affecting projections for future sea level rise. Key Points: Antarctic accumulation reconstruction using paleoclimate data assimilation finds modest (∼1 mm) 20th‐century sea level mitigationWe find similar 20th‐century trends to previous work; lower sea level mitigation (1 vs. 10 mm) is due to the 19th‐century baselineUncertainty in past East Antarctic accumulation limits confidence in future projections of Antarctic sea level mitigation [ABSTRACT FROM AUTHOR]

Antarctica is of great importance in terms of global warming, the sustainability of resources, and the conservation of biodiversity. However, due to 99.66% of the continent being covered in ice and snow, geological research and geoscientific study in Antarctica face huge challenges. Geophysical surveys play a crucial role in enhancing comprehension of the fundamental structure of Antarctica. This study used bibliometric analysis to analyze citation data retrieved from the Web of Science for the period from 1982 to 2022 with geophysical research on Antarctica as the topic. According to the analysis results, the amount of Antarctic geophysical research has been steadily growing over the past four decades as related research countries/regions have become increasingly invested in issues pertaining to global warming and sustainability, and international cooperation is in sight. Moreover, based on keyword clustering and an analysis of highly cited papers, six popular research topics have been identified: Antarctic ice sheet instability and sea level change, Southern Ocean and Sea Ice, tectonic activity of the West Antarctic rift system, the paleocontinental rift and reorganization, magmatism and volcanism, and subglacial lakes and subglacial hydrology. This paper provides a detailed overview of these popular research topics and discusses the applications and advantages of the geophysical methods used in each field. Finally, based on keywords regarding abrupt changes, we identify and examine the thematic evolution of the nexus over three consecutive sub-periods (i.e., 1990–1995, 1996–2005, and 2006–2022). The relevance of using geophysics to support numerous and diverse scientific activities in Antarctica becomes very clear after analyzing this set of scientific publications, as is the importance of using multiple geophysical methods (satellite, airborne, surface, and borehole technology) to revolutionize the acquisition of new data in greater detail from inaccessible or hard-to-reach areas. Many of the advances that they have enabled be seen in the Antarctic terrestrial areas (detailed mapping of the geological structures of West and East Antarctica), ice, and snow (tracking glaciers and sea ice, along with the depth and features of ice sheets). These valuable results help identify potential future research opportunities in the field of Antarctic geophysical research and aid academic professionals in keeping up with recent advances. [ABSTRACT FROM AUTHOR]

The NASA Atmospheric Tomography Mission (ATom) completed four seasonal deployments (August 2016, February 2017, October 2017, May 2018), each with regular 0.2–12 km profiling by transecting the remote Pacific Ocean and Atlantic Ocean basins. Additional data were also acquired for the Southern Ocean, the Arctic basin, and two flights over Antarctica. ATom in situ measurements provide a near-complete chemical characterization of the ∼ 140 000 10 s (80 m by 2 km) air parcels measured along the flight path. This paper presents the Modeling Data Stream (MDS), a continuous gap-filled record of the 10 s parcels containing the chemical species needed to initialize a gas-phase chemistry model for the budgets of tropospheric ozone and methane. Global 3D models have been used to calculate the Reactivity Data Stream (RDS), which is comprised of the chemical reactivities (production and loss) for methane, ozone, and carbon monoxide, through 24 h integration of the 10 s parcels. These parcels accurately sample tropospheric heterogeneity and allow us to partially deconstruct the spatial scales and variability that define tropospheric chemistry from composition to reactions. This paper provides a first look at and analysis of the up-to-date MDS and RDS data including all four deployments (Prather et al., 2023, 10.7280/D1B12H). ATom's regular profiling of the ocean basins allows for weighted averages to build probability densities for the key species and reactivities presented here. These statistics provide climatological metrics for global chemistry models, e.g., the large-scale pattern of ozone and methane loss in the lower troposphere and the more sporadic hotspots of ozone production in the upper troposphere. The profiling curtains of reactivity also identify meteorologically variable and hence deployment-specific hotspots of photochemical activity. Added calculations of the sensitivities of the production and loss terms relative to each species emphasize the few dominant species that control the ozone and methane budgets and whose statistical patterns should be key model–measurement metrics. From the sensitivities, we also derive linearized lifetimes of ozone and methane on a parcel-by-parcel basis and average over the basins, providing an observational basis for these previously model-only diagnostics. We had found that most model differences in the ozone and methane budgets are caused by the models calculating different climatologies for the key species such as O 3 , CO, H 2 O, NO x , CH 4 , and T , and thus these ATom measurements make a substantial contribution to the understanding of model differences and even identifying model errors in global tropospheric chemistry. [ABSTRACT FROM AUTHOR]

Global warming has become one of the most prominent global issues, and Antarctic ice sheet is one of the indicator of global climate change. Satellite imagery has become an important means of monitoring the changes in Antarctic ice sheet. Due to the high overlap of satellite imaging swaths, the existing Antarctica images have the disadvantages of long period of imagery acquisition, large temporal difference among the mosaic images, and low utilization of satellite resource. This paper proposes a satellite imaging mission planning method for fast Antarctica coverage. First, the imaging time window is forecasted within the specified imaging time range to obtain all the visible time windows of the imaging satellite to Antarctica. Then, taking the selection of each time window and the satellite swing angle in each time window as decision variables, and the satellite attitude maneuver ability as constraint, an imaging mission model including two objective functions with minimum number of imaging time windows and the maximum coverage rate is established. To solving the proposed multi-objective optimization model, an improved real-binary hybrid LMOCSO (large-scale multi-objective optimization based on a competitive swarm optimizer) is proposed in this paper. Finally, a simulation experiment was performed using Gaofen-3 satellite to verify the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

The concept of multiple scaling regimes in temperature time series is examined, with emphasis on the question whether or not a mono-scaling model can be rejected from the data at hand. A model with only one regime is simpler and is preferred if this explains the observed variability. Our analysis of spectra from reconstructed air temperature from Greenland and Antarctica ice cores shows that a scale break around centennial time scales is evident for the last glacial period, but not for the Holocene. Nor by analysing a number of late Holocene multiproxy temperature reconstructions can a significant scale break be identified. Our results indicate that a mono-scaling model cannot be rejected as a null model for the Holocene climate up to at least millennial time scales, although it can be rejected for the glacial climate state. The scale break observed from the glacial time ice core records is likely caused by the influence of Dansgaard-Oeschger events and teleconnections to the Southern Hemisphere on centennial time scales. From our analysis we conclude that the two-regime model is not sufficiently justified for the Holocene to be used for temperature prediction on centennial time scales. [ABSTRACT FROM AUTHOR]

Cyanobacteria form diverse communities and are important primary producers in Antarctic freshwater environments, but their geographic distribution patterns in Antarctica and globally are still unresolved. There are however few genomes of cultured cyanobacteria from Antarctica available and therefore metagenomeassembled genomes (MAGs) from Antarctic cyanobacteria microbial mats provide an opportunity to explore distribution of uncultured taxa. These MAGs also allow comparison with metagenomes of cyanobacteria enriched communities from a range of habitats, geographic locations, and climates. However, most MAGs do not contain 16S rRNA gene sequences, making a 16S rRNA gene-based biogeography comparison difficult. An alternative technique is to use large-scale k-mer searching to find genomes of interest in public metagenomes. This paper presents the results of k-mer based searches for 5 Antarctic cyanobacteria MAGs from Lake Fryxell and Lake Vanda, assigned the names Phormidium pseudopriestleyi FRX01, Microcoleus sp. MP8IB2.171, Leptolyngbya sp. BulkMat.35, Pseudanabaenaceae cyanobacterium MP8IB2.15, and Leptolyngbyaceae cyanobacterium MP9P1.79 in 498,942 unassembled metagenomes from the National Center for Biotechnology Information (NCBI) Sequence Read Archive (SRA). The Microcoleus sp. MP8IB2.171 MAG was found in a wide variety of environments, the P. pseudopriestleyi MAG was found in environments with challenging conditions, the Leptolyngbyaceae cyanobacterium MP9P1.79 MAG was only found in Antarctica, and the Leptolyngbya sp. BulkMat.35 and Pseudanabaenaceae cyanobacterium MP8IB2.15 MAGs were found in Antarctic and other cold environments. The findings based on metagenome matches and global comparisons suggest that these Antarctic cyanobacteria have distinct distribution patterns ranging from locally restricted to global distribution across the cold biosphere and other climatic zones. [ABSTRACT FROM AUTHOR]

Cyanobacteria in polar environments face environmental challenges, including cold temperatures and extreme light seasonality with small diurnal variation, which has implications for polar circadian clocks. However, polar cyanobacteria remain underrepresented in available genomic data, and there are limited opportunities to study their genetic adaptations to these challenges. This paper presents four new Antarctic cyanobacteria metagenome-assembled genomes (MAGs) from microbial mats in Lake Vanda in the McMurdo Dry Valleys in Antarctica. The four MAGs were classified as Leptolyngbya sp. BulkMat.35, Pseudanabaenaceae cyanobacterium MP8IB2.15, Microcoleus sp. MP8IB2.171, and Leptolyngbyaceae cyanobacterium MP9P1.79. The MAGs contain 2.76 Mbp - 6.07 Mbp, and the bin completion ranges from 74.2-92.57%. Furthermore, the four cyanobacteria MAGs have average nucleotide identities (ANIs) under 90% with each other and under 77% with six existing polar cyanobacteria MAGs and genomes. This suggests that they are novel cyanobacteria and demonstrates that polar cyanobacteria genomes are underrepresented in reference databases and there is continued need for genome sequencing of polar cyanobacteria. Analyses of the four novel and six existing polar cyanobacteria MAGs and genomes demonstrate they have genes coding for various cold tolerance mechanisms and most standard circadian rhythm genes with the Leptolyngbya sp. BulkMat.35 and Leptolyngbyaceae cyanobacterium MP9P1.79 contained kaiB3, a divergent homolog of kaiB. [ABSTRACT FROM AUTHOR]

The widespread perception of New Zealand is of a group of remote islands dominated by reptiles and birds, with no native mammals except a few bats. In fact, the islands themselves are only part of a wider New Zealand Region which includes a large section of Antarctica. In total, the New Zealand Region has at least 63 recognised taxa (species, subspecies and distinguishable clades) of living native mammals, only six of which are bats. The rest comprise a large and vigorous assemblage of 57 native marine mammals (9 pinnipeds and 48 cetaceans), protected from human knowledge until only a few centuries ago by their extreme isolation in the southwestern Pacific Ocean. Even after humans first began to colonise the New Zealand archipelago in about 1280 AD, most of the native marine mammals remained unfamiliar because they are seldom seen from the shore. This paper describes the huge contrast between the history and biogeography of the tiny fauna of New Zealand's native land mammals versus the richly diverse and little-known assemblage of marine mammals. [ABSTRACT FROM AUTHOR]

Long-term monitoring projects are becoming more than ever crucial in assessing the effects of climate change on marine communities, especially in Antarctica, where these changes are expected to be particularly dramatic. Detailed studies of the Antarctic benthos are in fact particularly important for a better understanding of benthos dynamics and potential climate-driven shifts. Here, due to the extreme fragility of benthic communities, non-destructive techniques represent the best solution in long-term monitoring programs. In this paper we report new results from 2017, 2018, 2019 photogrammetric campaigns within the Italian National Antarctic Research Program (PNRA). A new protocol of data acquisition and multi-temporal processing that provides co-registered 3D point clouds between the three years without control points nor direct georeferencing methods is presented. This is achieved by adding a level of image understanding leveraging semantic segmentation with convolutional neural network (CNN) of the benthic features. Slow growing (estimated less than a mm per year) organisms, such as Corallinales (Rhodophyta algae), represent a natural stable pattern, leveraged to automatically orient in the same reference system the photogrammetric surveys of different epochs. This approach is also proved to be effective in improving the orientation of adjacent strips acquired within the same campaign. Within the paper an in depth analysis of the achieved results shows the effectiveness of the implemented procedure. [ABSTRACT FROM AUTHOR]

In 1980, at the invitation of Australia, the first Chinese scientists went to Antarctica. China was therefore a relative 'latecomer' to engage in Antarctic science. In the period since its first Antarctic expedition in 1984, China's presence in Antarctica has expanded both in terms of its logistics and infrastructure and its scientific research. This paper outlines the development of China's national Antarctic programmes under the influence of corresponding national policies from the late 1970s to the present, noting the application of various scientific disciplines to Antarctic fields. The paper outlines and analyses the broadening and deepening of China's Antarctic science research, infrastructure and engagement. [ABSTRACT FROM AUTHOR]

Remote sensing is a very powerful tool that has been used to identify, map and monitor Antarctic features and processes for nearly one century. Satellite remote sensing plays the main role for about the last five decades, as it is the only way to provide multitemporal views at continental scale. But the emergence of small consumer-grade unoccupied aerial vehicles (UAVs) over the past two decades has paved the way for data in unprecedented detail. This has been also verified by an increasing noticeable interest in Antarctica by the incorporation of UAVs in the field activities in diversified research topics. This paper presents a comprehensive review about the use of UAVs in scientific activities in Antarctica. It is based on the analysis of 190 scientific publications published in peer-reviewed journals and proceedings of conferences which are organised into six main application topics: Terrestrial, Ice and Snow, Fauna, Technology, Atmosphere and Others. The analysis encompasses a detailed overview of the activities, identifying advantages and difficulties, also evaluating future possibilities and challenges for expanding the use of UAV in the field activities. The relevance of using UAVs to support numerous and diverse scientific activities in Antarctica becomes very clear after analysing this set of scientific publications, as it is revolutionising the remote acquisition of new data with much higher detail, from inaccessible or difficult to access regions, in faster and cheaper ways. Many of the advances can be seen in the terrestrial areas (detailed 3D mapping; vegetation mapping, discrimination and health assessment; periglacial forms characterisation), ice and snow (more detailed topography, depth and features of ice-sheets, glaciers and sea-ice), fauna (counting penguins, seals and flying birds and detailed morphometrics) and in atmosphere studies (more detailed meteorological measurements and air-surface couplings). This review has also shown that despite the low environmental impact of UAV-based surveys, the increasing number of applications and use, may lead to impacts in the most sensitive Antarctic ecosystems. Hence, we call for an internationally coordinated effort to for planning and sharing UAV data in Antarctica, which would reduce environmental impacts, while extending research outcomes. [ABSTRACT FROM AUTHOR]

Antarctica is a crucial regulator of the world's climate, and as environmental security permeates global security, using Antarctic science to better understand climate is becoming increasingly pressing. Although the Australian Government has recognised that climate change poses 'a current and existential national security' threat and has acknowledged Antarctica's importance regarding the earth's global climate system, the focus of Australia's intelligence community pertaining to Antarctica currently remains restricted to upholding the military-security and diplomatic goals of the Antarctic Treaty System (ATS). This current focus aims to hedge against the possibility of conflict on, or over, the frozen continent via 'working the ATS', however, this paper argues that Antarctic climate science holds a greater capacity to deliver security outcomes for Australia. Antarctic climate science offers opportunities regarding intelligence for Antarctica, that is, securing Australia's Antarctic interests, as well as regarding intelligence from Antarctica; by enhancing natural disaster preparedness, bolstering broader strategic planning, as well as furthering diplomacy and the legitimisation of Australia's leadership on, and over, the frozen continent. It is recommended that the Commonwealth Government establish a climate intelligence working group to ensure the utility of climate science to security and intelligence is realised. [ABSTRACT FROM AUTHOR]

Atmospheric electricity parameters (AEP) measurements from Antarctica predominantly feature either the potential gradient (PG) and/or air‐Earth current (AEC) density. We report for the first time simultaneous measurements of the bipolar ions concentration/conductivity, PG, and AEC density. AEP measurements were carried out at Maitri (70.8°S, 11.8°E) from December 2018 to November 2019. We formulated a few criteria, irrespective of the weather conditions, to select the electrically quiet days and some additional criteria based on the conductivity measurements to discern globally representative data (GRD) from such days. The measurements of the PG and AEC density over the Antarctic plateau demonstrated the diurnal curves similar to the Carnegie pattern, which represents the global thunderstorms and electrified shower clouds (ESCs) occurring on different continents and oceans, we regard the data having such trend as GRD. We found significant variability in the concentration of small bipolar ions/conductivity in the austral summer which in turn affects GRD. However, the concentration of bipolar ions is nearly consistent at ∼250 negative ions cm−3 and ∼300 positive ions cm−3 in winter and enhances the probability of GRD. Such differences can arise out of the prevalent planetary boundary layer processes in the two seasons. When the PG varied between ∼50 Vm−1 and ∼150 Vm−1 and the maximum range of conductivity variations was ∼0.2 × 10−14 ℧ m−1, the AEPs represented the signatures of the global thunderstorm and ESC activities. Plain Language Summary: Monitoring of the atmospheric electricity parameters is a simple technique to monitor global thunderstorm activity and electrified shower clouds. For this, the data need to be free from local disturbances. Obtaining such data in Antarctic Plateau was found to be successful. On the other hand, the coastal Antarctic stations, experience local or regional contributions in it. This paper attempts to provide some techniques to obtain globally representative data (GRD). This paper suggests that the diurnal variation of the concentration of bipolar small ions strongly impacts the GRD. Therefore a day free from the diurnal variation of the concentration of bipolar ions is essential to discern the global signals. The winter season appears to be a better season for this as the summer season experiences mild convection activity that causes local and regional electrical signals that contaminate the data. Key Points: Atmospheric electrical conductivity is the key parameter to discern globally representative data (GRD) over the Maitri, AntarcticaGRD is discernible on a day when conductivity is consistent, and such days are most common in local winterIn the austral summer, the planetary boundary layer (PBL) processes produce local electrical signals that interfere with the global signals [ABSTRACT FROM AUTHOR]

Its isolation and extreme climate means Antarctica is one of the world's richest regions for untouched geoheritage. The potential of mining in Antarctica is often talked of in public discourse as a future threat to Antarctica even though the prohibition on mining is absolute and is likely to stay so indefinitely. As such mining does not pose a realistic threat to Antarctica's geoheritage. The impacts of scientific research and tourism pose more pressing challenges to Antarctica's geoheritage. This paper considers emerging debates in the Antarctic Treaty System on the need for further protection of Antarctica's geoheritage. After considering the concept of geoheritage the paper considers key threats to Antarctic geoheritage. The role of Antarctic Specially Protected Area system in the protection of Antarctica's geoheritage is then considered as is the draft code of conduct on geosciences field research currently being developed within the Antarctic Treaty System. The final part of the paper then goes on to examine how the Antarctic Treaty system could in part draw on the experience of other international initiatives, including the frameworks associated with the UNESCO Global Geoparks movement in developing an Antarctic System for protection of geoheritage. [ABSTRACT FROM AUTHOR]

The Antarctic Treaty 1959 has now been in place for 60 years and is regarded by informed commentators as one of the most successful multi-party international treaty systems. This paper provides an opportunity to look back and take stock of previous success, and more importantly, an opportunity to assess the future prospects of the treaty system. New Zealand has played a key role in the Antarctic Treaty system and has had a long involvement with Antarctica since accepting the transfer of sovereignty over the Ross Dependency in 1923. This paper therefore focuses on the effectiveness of the Antarctic Treaty system through a New Zealand lens. [ABSTRACT FROM AUTHOR]

Flavobacterium sp. AUG42 is a cellulase-producing bacterium isolated from the Antarctic oligochaete Grania sp. (Annelida). In this work, we report that AUG42 produces a glycoside hydrolase cocktail with CMCase, PASCase and cellobiase activities (optimum pHs and temperatures ranging from 5.5 to 6.5 and 40 to 50 °C, respectively). The time-course analyses of the bacterial growth and cellulase production showed that the cocktail has maximal activity at the stationary phase when growing at 16 °C with filter paper as a cellulosic carbon source, among the tested substrates. The analyses of the CAZome and the identification of secreted proteins by shotgun Mass Spectrometry analysis showed that five glycoside hydrolyses are present in the bacterial secretome, which probably cooperate in the degradation of the cellulosic substrates. Two of these glycoside hydrolyses may harbor putative carbohydrate binding modules, both with a cleft-like active site. The cellulolytic cocktail was assayed in saccharification experiments using carboxymethylcellulose as a substrate and results showed the release of glucose (a fermentable sugar) and other reducing-sugars, after 24 h incubation. The ecological relevance of producing cellulases in the Antarctic environment, as well as their potential use in the bio-refinery industry, are discussed. [ABSTRACT FROM AUTHOR]

Human civilization has reached an unprecedented height, but the industrialization of economic development also brings global warming, ozone depletion, acid rain, fresh water resources crisis, energy shortage, and environmental problems. In autumn and winter, haze becomes the usual state in the modern society, and PM2.5 has been becoming an important form of air pollution. The research found that PM2.5 brings great influence to the human body or daily life. To some extent, the PM2.5 also affects the propagation of electromagnetic waves near the ground, reducing the transmission performance of electromagnetic wave. Based on Mie scattering theory, this paper qualitatively analyzed the scattering effects of PM2.5 particles on every frequency band of electromagnetic wave in daily use. Then the paper takes the satellite navigation signals as a research example, selecting university of Wyoming Davis stations in Antarctica sounding data by measuring the tropospheric atmospheric meteorological parameters (including the atmosphere pressure, geopotential height of different layers, dew point temperature, relative humidity and specific humidity, wind direction, wind speed, and temperature). The paper inversed the refractive index distribution of the troposphere based on AlexNet model and described the error quantitatively. The simulation results show that the estimated error is less than 5.1455%, proving the high accuracy of the AlexNet model. To test the influence of PM2.5, the paper takes Jiuquan, a city with serious pollution, as an example. Comparison between the inversion results and IGS products shows that high concentration of PM2.5 pollution has little influence on the inversion of refractive index profile. [ABSTRACT FROM AUTHOR]

The Antarctic Treaty has significant strategic and security interests for Australia. Australia claims 42 per cent of the continent, and the Antarctic Treaty established the area below 60o S as a non-militarised region where military manoeuvres, weapons testing and nuclear explosions are prohibited. The benefits to Australia of maintaining the strength of the Antarctic Treaty System are manifold. This paper sets out the importance to Australia of the Antarctic Treaty System; Australia's Antarctic activities; and current geopolitical tensions in the system. It argues that Australia should continue to invest practical and diplomatic efforts to secure its Antarctic interests and the strength of the System into the future. [ABSTRACT FROM AUTHOR]

Contemporary archaeology brings a unique perspective from which to critically think about Antarctic Treaty System conservation policies and practices concerning material things. The paper begins by highlighting how they have relied on several underlying assumptions, which we summarise as the 'wilderness' and 'heritage' principles. It then discusses how these policies and practices have often led to non‐sustainable or non‐inclusive outcomes. In particular, the application of the wilderness and heritage principles to environmental conservation has, on the one hand, reinforced the dominant images and narratives of Antarctica, selectively neglecting and erasing diverse human and non‐human stories, and on the other hand, led to human–thing entanglements that are currently difficult to overcome. The paper's conclusions encourage readers to envision more inclusive and sustainable conservation models by challenging the assumptions underlying current policies and practices. [ABSTRACT FROM AUTHOR]