Ukrainian Antarctic Journal

The dynamics of Trooz Glacier, Antarctic Peninsula, by satellite remote sensing data

S. Kadurin, V. Kadurin — Sun, 31 Dec 2023 00:00:00 +0200

The paper studies the ice cover of the Trooz Glacier, Kyiv Peninsula, West Antarctic Peninsula. The main goal of the work is to study the velocity dynamics of various parts of the Trooz Glacier in 2016–2022 based on remote sensing data and to compare them with changes in meteorological variables. The glacier’s velocity was determined using 7-year data from the Copernicus Sentinel-1 satellite system based on the offset tracking technique. The characteristics of climatic changes during the same time intervals were determined according to the POWER project from NASA. To analyze the velocity field of the Trooz Glacier over time, 100 control points were selected along the entire valley from the mouth to the upland of the tributaries. For these points, values of the glacier velocity were calculated every 12 days for seven years, from 23.11.2015 to 28.12.2022. The entire glacier valley was divided into subclusters with their own average surface velocities and accelerations. To determine the level of climate change’s influence on the velocities of different parts of the Trooz Glacier, we used the method of cross-correlation. The ice flow reacted to climatic changes with a certain delay. Annual velocity fluctuations of various parts and a slight glacier movement acceleration from 2015 to 2022 were identified. The latter amounted to 7–9% of the 2016-year speed. At the same time, only in the terminus area during the studied period was there a slight slowdown in the average annual velocity detected from 2.25 m day^–1 in 2016 to 2.1 m day^–1 in 2022. The most intensive climatic parameters affect the middle and lower parts of the Trooz Glacier. Among the main parameters, the near-surface environment temperature can be seen as the most influential force. Temperature changes impact the glacier velocity within the first 12 to 36 days; the effect can appear later with lag intervals of up to 120 days. The role of environmental temperature is significant for the middle part of the glacier, where its valley becomes wide. For the lower part and terminus region of the glacier, the temperature effect is most significant, with the reaction of the ice flow to temperature changes occurring in the coming days. Shortwave solar radiation and ultraviolet index were also established as influencers, but only for the lower and middle glacier parts, with a lag from 12 to 48 days. The influence of the precipitation amount was the most detectable only in the lower part of the glacier.

Oceanographic, marine geological and sedimentary research in the coastal area of West Antarctica

O. Olshtynska, S. Kadurin, Ye. Nasedkin — Sun, 31 Dec 2023 00:00:00 +0200

We present the results of studying, mapping, and bathymetric profiling of the sea bottom relief from the research vessel Noosfera and the map of the Argentine Islands’ underwater relief based on current data. The paper contains a brief description of the material, granulometric (grain size analyses), and mineral composition of bottom sediments collected during the expedition in deep and shallow sites, as well as an analysis of sedimentation conditions in the region. We also provide the results of a study of the taxonomical and ecological diversity of siliceous microfossils of bottom sediments in Penola Strait; the material is illustrated with a table of images of diatoms studied using the scanning electron microscope. The fieldwork methods on the research vessel and in the laboratory and analytic works are described.

Abiotic pathways for the formation of ozone-depleting and other trace gases in the polythermal glacier on Galindez Island, Maritime Antarctica

M. Bazylevska, V. Bogillo — Sun, 31 Dec 2023 00:00:00 +0200

The study aims to analyze trace gases in the composition of the polythermal glacier on Galindez Island in Maritime Antarctica (65°14' S, 64°16' W) and possible pathways for their abiotic formation in the snowpack and the superimposed or old cold ice. Polythermal glaciers are the most sensitive indicators of climate change. They are ideal for studying chemical post-depositional processes that alter the trace gas composition of the ice core air and the mechanisms involved under the current climate warming. This study is the first attempt to assess the concentration range of a large number of trace gases (except the previously studied O₂, N₂, Ar, and CO₂) in polythermal and temperate glaciers, which are widespread in Greenland, Svalbard, Canadian Arctic, Alaska, Alps, Andes, Tibet, Altai, and Maritime Antarctica. The ice porosity varies from 0.6% to (unique to superimposed ice) 7%. Qualitative analysis by GC-MS was done for more than 200 organic and inorganic trace gases. A quantitative analysis of 27 compounds was performed along the vertical profile of the glacier, including CO₂and N₂O, freons, chlorine-based solvents that are prohibited by the Montreal Protocol, F-, Cl-, Br- and I-containing halocarbons, COS, CS₂, CH₃SCH₃, CH₃SSCH₃, and propene. Statistical data (mean, minimal, and maximum values) for ten horizontal levels of the glacier were calculated for their mixing ratios compared to background air. Most halocarbons, sulfur-containing compounds, and propene are characterized by high enrichment factors. This suggests that the species can be formed in the snowpack and firn of the glacier or its deep bubbling superimposed and old cold ice. Possible pathways of the gases formation include direct and indirect photochemical reactions of the triplet state dissolved organic matter (DOM) in snowpack without or in the presence of X– ions (X = Cl, Br, I), dark redox reactions of Fe³⁺, Mn⁴⁺, Cu²⁺, O₃, H₂O₂or radicals HO_x(HO_x= HO·,HO₂·) with DOM in the presence of X–, reactions of HOX with DOM (with the participation of HO_x, H₂O₂or O₃), free radical reactions with alkenes, alkynes, and alkyl radicals, and miscellaneous reactions of methylmethionine and/or S-containing peptides.

Variability of extreme precipitation in West Antarctica and its response to the Amundsen Sea Low changes

L. Pysarenko, D. Pishniak, M. Savenets — Sun, 31 Dec 2023 00:00:00 +0200

Changes in precipitation extremes over West Antarctica and the Antarctic Peninsula belong to the observed consequences of current climate change. We discuss the spatio-temporal patterns of extreme precipitation and their relationships with the Amundsen Sea Low (ASL) parameters. Based on the ERA5 reanalysis data, the 95th percentile of daily precipitation totals was estimated and linked to the ASL parameters over the main glacier basins in the region. The 95th percentile of precipitation varied from 5 mm to over 40 mm over the region, showing higher values along the coastline and reaching the maximum over the west coast of the Antarctic Peninsula. The tendencies of extreme precipitation vary from –3 to 4 mm per decade and enhance the observed spatial distribution differences. On average, extreme precipitation events covered 4.7–4.9% of the basins’ area. All dependencies had a well-detected seasonality. Both total and extreme precipitation varied under the ASL fluctuations, showing significant average-to-strong correlations. The ASL shifts to the west caused a decrease in precipitation over the Amundsen Sea and an increase over the Antarctic Peninsula. The ASL deepening (lower atmospheric pressure of the system) resulted in a precipitation decrease over the Getz Ice Shelf and a precipitation increase over the western part of the Antarctic Peninsula. There are two regions with opposite responses of precipitation to the ASL changes: the western part over the Getz Ice Shelf with nearby marine areas, and the eastern part covering the Antarctic Peninsula, Pine Island glaciers, the Abbot Ice Shelf, and the Bellingshausen Sea. The obtained results are crucial for our understanding of extreme precipitation occurrences over West Antarctica in recent decades under climate change.

Long-distance HF radio waves propagation during the April 2023 geomagnetic storm by measurements in Antarctica, in Europe, and aboard RV Noosfera

Sun, 31 Dec 2023 00:00:00 +0200

The paper aims at an experimental study of the mechanisms of long-distance high-frequency (HF) propagation and spatial and temporal variations of the ionospheric parameters during the first hours of a severe geomagnetic storm of April 23, 2023 by spatially separated measuring equipment located at the research vessel (RV) Noosfera, the Ukrainian Antarctic Akademik Vernadsky station (hereinafter Vernadsky), and the LOFAR observatory PL610 in Borowiec (Poland). High-frequency vertical and oblique sounding techniques of the ionosphere were used. Geospace measurements were carried out synchronously. During the first hours of the geomagnetic storm of April 23–24, 2023, unexpectedly well-correlated variations in the Doppler frequency shifts of HF signals emitted from Vernadsky were observed at the RV Noosfera and the PL610 station. Furthermore, variations in Doppler frequency shifts of HF signals strongly correlate with magnetic field records in Antarctica and Poland. Variations in the frequency of HF signal spectral components, distinguishable during storm conditions, are utilized to clarify the mechanism of long-distance HF propagation and estimate the vertical velocity of ionospheric layers. Signals of HF CHU time radio station (Canada) at 7850 and 14670 kHz were unexpectedly observed in all receiving sites. Most probably, the CHU station radio signals registered during the initial stage of the geomagnetic storm were scattered on the polar ovals’ ionospheric inhomogeneities and propagated further along the return (long arc of the great circle) paths. Redistribution of the ionospheric plasma during the geomagnetic storm leads to the formation of HF radio propagation channels absent under quiet conditions.

Records of vagrant and visitor bird species in the Fildes Region, King George Island, Maritime Antarctic, between 1980 and 2023

C. Braun, H. Grämer, H.-U. Peter — Sun, 31 Dec 2023 00:00:00 +0200

We provide information on vagrant and visitor bird species recorded in the Fildes Region (King George Island, South Shetlands, Antarctic) during the long-term bird monitoring programme between the 1979–1980 and 2022–2023 seasons. The total ice-free territory covers approximately 35 km2, making it one of the largest ice-free areas in the Western Antarctic Peninsula region. In addition to 13 breeding and one potentially breeding bird species, we recorded 28 non-breeding bird species. Of these non-breeding bird species, we defined 18 as vagrants and 10 as visitors. The vagrant and visitor bird species recorded were representatives of the families Spheniscidae, Diomedeidae, Procellariidae, Pelecanoididae, Laridae, Ardeidae, Scolopacidae, and Anatidae. Furthermore, we include information on the frequency of observations of bird species that do not breed in the study area. Most frequently observed were white-rumped sandpiper, cattle egret, emperor penguin, macaroni penguin, and king penguin. These data contribute to knowledge of rare birds in the Antarctic. Together with similar studies, this information may provide valuable clues to unusual environmental conditions that allow vagrants to reach regions beyond their usual distribution range. Furthermore, long-term data on rare bird sightings can indicate a potential expansion of the breeding range of individual species. Such studies may be relevant for the evaluation of environmental changes that are already occurring as a result of current climate change, e.g., changes in sea ice cover or food web structures.

The first record and description of females of the genus Acunemella Andrássy, 2002 (Nematoda, Nordiidae) from the South Shetland Islands

S. Susulovska, A. Susulovsky — Sun, 31 Dec 2023 00:00:00 +0200

There is a single record of the rare terrestrial nematode genus Acunemella Andrássy, 2002 (Nematoda, Nordiidae) in the type locality on Chiloé Island (South Chile). The type species of the genus, Acunemella torta Andrássy, 2002, was described on the basis of only two male specimens. In this article, mature females of the genus Acunemella are described for the first time based on morphology and morphometrics of specimens from Deception Island (South Shetland Islands). The current article is the first report of this genus from the Antarctic region. Females from Deception Island are characterized by a didelphic-amphidelphic genital system, with both branches almost equally developed, a distinct muscular sphincter between oviduct and uterus, a curling outer surface of the uterus, pars refringens vaginae moderately sclerotized, with two relatively large (4–6 × 12–13 μm) rounded triangular pieces, a vulval region with well-developed cuticular folds. Morphologically, females are similar to originally described males but differ by longer bodies, more distinctly offset lip regions and the shape of sperm cells in uterus. Verifying the taxonomic status of the population described in this article requires the analysis of additional materials.

Thirty years of Ukrainian Antarctic Research: Assessing the National Antarctic Program’s institutional achievements within the Antarctic Treaty System

E. Dykyi, D. Cheberkus, A. Fedchuk, O. Pnyovska, V. Malanchuk — Sun, 31 Dec 2023 00:00:00 +0200

Ukraine made a significant contribution to the study of the Antarctic. People from Ukraine were part of the expeditions that discovered and explored the Antarctic and conquered the South Pole in the XIX – beginning of the XX century. From the end of the 1950s to the beginning of the 1990s, Ukrainian researchers and engineers made valuable efforts to establish and develop Soviet Antarctic expeditions. With the acquisition of independence, the difficult and ambitious path of studying the Antarctic under the flag of Ukraine began. This article provides a historical overview of the main institutional achievements in the development of Ukrainian Antarctic research from 1993 to the present. Also, it outlines the current state, challenges, and prospects for further developing Ukraine’s National Antarctic Program within the Antarctic Treaty System. The gradual development of the State Special-Purpose Antarctic Research Programs is noted, and the main results are presented. The scientific potential and contribution to international scientific cooperation of Ukraine’s key Antarctic infrastructure facilities are revealed – Vernadsky station as a multi-purpose observatory for monitoring geophysical processes and the impact of climate change on the Antarctic ecosystems, and the ice-capable research vessel Noosfera. It is shown that the environmental protection initiatives and measures developed by Ukraine to regulate tourist activities are an important contribution to the development of the international legal regime of Antarctica.

Monitoring the technical condition of the fuel storage facility at the Ukrainian Antarctic Akademik Vernadsky station

Yu. Posypaiko, A. Andreev — Sun, 31 Dec 2023 00:00:00 +0200

The paper examines the technical condition of metal structures of the fuel storage facility and pipelines at the Ukrainian Antarctic Akademik Vernadsky station, the development and implementation of measures to increase the reliability of their work, and the organization of their regular annual monitoring. At the preparatory stage, the analysis of design and operational documentation for fuel storage facility VST-200 was performed, technical inspection methods were selected (ultrasonic thickness measurement, tightness control, visual and eddy current control, level and theodolite surveys, and others), equipment and auxiliary equipment were selected for performing diagnostic work by non-destructive testing methods (flaw-detectors, thickness gauge, leak detector, level, theodolite, and others). An instrumental inspection of the condition of metal structures of the double-skinned fuel storage tank VST-200 and pipelines was carried out using non-destructive testing methods to detect defects and damage in structural elements and welded joints, as well as inspection of the condition of the foundation and base of the tank. Anti-corrosion work was carried out on the bottom of the station's fuel tank VST-200, and pipelines with corrosion damage were replaced. All elements (foundations, walls, bottoms, and roofs of the external and internal reservoirs) are in working technical condition. They meet the norms and standards for design, manufacture, and operation. The static strength of the walls of both reservoirs is adequate for the project and current regulations. Thanks to the anti-corrosion work on the bottom of the internal tank, it is possible to continue its operation until 2029 by providing the rules of the technical operation of the fuel storage facilities and the organization of annual monitoring of the technical condition of the tank and technological equipment. The old decommissioned fuel storage tank HST-150 is modified into a dry solid materials store.