Ukrainian Antarctic journal

Studying the suspended matter in Antarctic Peninsula coastal waters to understand the local geological and ecological processes

Ye. Nasiedkin — 2023-02-15

We review comprehensive international studies of the mineral and organic suspended matter in the South Ocean. We suggest an experimental design to monitor these parameters at the Akademik Vernadsky station, where this research will be introduced. Applied aspects of marine suspension's qualitative and quantitative properties are a subject of active research, given its significance for several physical and biochemical processes such as sedimentation. Therefore, geological, biological, and climatological studies of the Antarctic shelf employ continuous observations of the suspension’s distribution. Work in this area is aimed at investigating the qualitative and quantitative properties of the suspension and analysis of its organic and mineral components, determining the dynamics of the currents and transportation of suspended matter, the nature of sedimentation processes, their seasonality and connection with the direction of currents and movement of sea ice. To determine the possibility of researching the suspended matter in the waters around the Akademik Vernadsky station, we analyze our long-term experience of using sedimentation traps to study the suspended matter flows in the seas and rivers of Ukraine. The developed complex of field equipment can be used to sample the suspended matter in waters adjacent to the Akademik Vernadsky station. The light single-cylinder sedimentation traps were transferred to the team of the Ukrainian Antarctic Expedition 2022 for further use at the Vernadsky station.

Increasing the accuracy of absolute measurements at the Argentine Islands geomagnetic observatory of the Ukrainian Antarctic Akademik Vernadsky station

Yu. Sumaruk — 2023-02-15

In recent years, the INTERMAGNET geomagnetic observatory Argentine Islands of Ukrainian Antarctic Akademik Vernadsky station, located at Galindez Island, has been modernized. New devices were installed at the observatory: reference three-component fluxgate magnetometer LEMI-025, one-component Mag-01H Fluxgate Declinometer/Inclinometer with non-magnetic Wild T1 Theodolite (DI-magnetometer), and scalar Overhauser magnetometers GSM-19 and GSM-90. These devices have a high resolution and can carry out measurements with greater accuracy. Also, new methods of absolute observations and variation processing were introduced. In 2022, a new DI-magnetometer was installed; it practically did not change the baseline values of the variometer LEMI-025 compared to previous years, which indicates the reliability of the results, but made observations much more convenient. We present the results of processing absolute observations, carried out by different methods. Different techniques of calculating these observations are described, and certain shortcomings or inaccuracies in their application are noted. Recommendations to eliminate the identified shortcomings are proposed. The results of processing of absolute observations by different techniques are compared and the reason for the inconsistency of certain values is found. A new method of calculation of absolute observations is proposed, which was used at the observatory, which showed quite good results. In the new methodology, the calculation of errors of the DI-magnetometer, namely: the zero offset of the magnetic sensor, the azimuth collimation error δ and the elevation collimation error ε of its sensitivity axis relative to the axes of theodolite, is initiated. Analysis of these errors allows identifying and sometimes correcting the errors in absolute measurements. The installation of new devices and the application of new calculation methods made it possible to ensure better data quality and convenience of measurements at the station, to automate the data processing, preparation, and minimizing the influence of the human factor.

The data processing and analysis methods for stratospheric ozone and planetary wave study

Y. Shi — 2023-02-15

We describe the methods and data sources for investigating the stratospheric ozone and planetary waves in the atmosphere in the framework of research provided by our international team. Selected ground-based and satellite instruments for ozone measurements and related reanalyses are described. Examples of data and analysis tools are shown. The technique of planetary wave spectral analysis under conditions of dynamic changes during sudden stratospheric warmings is presented. A brief description of the main results, obtained with the participation of the authors, using combined methods of analysis are considered. We describe procedures for the investigation of a long-term eastward displacement of the zonal ozone minimum over the Antarctic in the spring months, analysis of the spatial and temporal characteristics of the teleconnection between the tropical thermal source and the Antarctic stratosphere, and the creation of the predictive index used for the forecast of possible ozone hole anomalous development in spring months. Examples of application of analysis methods to retrieve the changes in the zonal asymmetry of the Arctic stratopause and features of the annual ozone cycle in connection with zonal ozone asymmetry are discussed.

Climate projections over the Antarctic Peninsula region to the end of the 21st century. Part III: clouds and extreme precipitation

A. Chyhareva — 2023-02-15

This paper focuses on the parameters that represent the characteristics of clouds and extreme precipitation events over the Antarctic Peninsula region, where clouds and precipitation play a crucial role in regional climate warming, particularly when a higher fraction of precipitation becomes liquid. In this work, we assess cloud and precipitation properties under climate change over the Antarctic Peninsula region under the Representative Concentrations Pathways (RCP) scenarios using model outputs of the Coordinated Regional Downscaling Experiment for polar regions (Polar CORDEX) for the 21st century. A similar approach was previously applied by authors for estimating projected changes in the temperature regime (Part I) and wet/dry indices (Part II) for the Antarctic Peninsula. We evaluated changes in cloud ice and condensed water contents, spatial distributions of both rain fraction and 95th percentile of total precipitation for the future periods, 2041–2060 and 2081–2100, for RCP4.5, RCP8.5 comparing them to the historical period of 1986–2005. We found that changes in studied parameters have similar tendencies and patterns under both scenarios, with more remarkable changes for the RCP8.5 scenario through the end of the 21st century. Analysis of obtained projections shows that all cloud amounts, liquid content in clouds, the annual fraction of rain in precipitation events, and frequency of extreme precipitation events will increase over the Antarctic Peninsula by the end of the 21st century under both RCP scenarios. The most significant changes are expected for the west coast and over the ocean to the west of the Antarctic Peninsula region, while the lowest changes are projected for the ridge of the Antarctic Peninsula mountains. However, the rates of expected changes vary within the broad Antarctic Peninsula region. While extreme event intensities will increase over the whole area, the changes will be most remarkable over the northwestern slopes of the Antarctic Peninsula, where Akademik Vernadsky station is located.

Lagrangian pathways under the Filchner-Ronne Ice Shelf and in the Weddell Sea

V. Maderich — 2023-02-15

The study’s objective is to construct Lagrangian pathways under the Filchner-Ronne Ice Shelf (FRIS) and in the Weddell Sea using the data of numerical simulation of currents and Lagrangian numerical methods. The results of modeling the circulation, temperature, and salinity in the Weddell Sea and the FRIS cavity from the Whole Antarctica Ocean Model were used to run the particle-tracking model (Parcels) for computing Lagrangian particle trajectories. The basic version of the Parcels model does not have an option for particle reflection from the solid boundaries, including the ice shelf. Therefore, the corresponding kernel was used in the study. To avoid errors in interpolation near the solid boundary when the model algorithm cannot find enough grid nodes around the particle, the function of particle recovery was implemented. To analyze the movement variations of the water masses under the FRIS, a set of particles was released in the Ronne Depression near the ice shelf front. Simulation continued for 20 years of particle movement. Particles were released at two depths: 350 m and 500 m, every 4 hr within the first 365 days. To characterize the redistribution of water masses, we calculated the ‘visitation frequency’, i.e., the percentage of the particles that visited each 2 × 2 km grid column at least once in a modeling period. The mean age of visits was
also calculated to characterize the age of water masses. The results of this analysis generally agreed with schemes based on water mass analysis. The released particles first move southward along the Ronne Trough. The flow then turns to the east, reaching the passage between Berkner Island and Henry Ice Rise after three years. After ten years, the released particles reach the Filchner Trough, through which water flows out to the shelf of the southern part of the Weddell Sea. Over time, the particles penetrate all parts of the cavity. The particles also cross the Ronne Shelf front and are carried away by currents on the Weddell Sea shelf. In
20 years, almost the same number of particles left the cavity through the Ronne ice front (43%) and the Filchner ice front (37%), whereas the rest of the particles (20%) remained under FRIS.

Microbiomes of Antarctic pearlwort (Colobanthus quitensis) of the maritime Antarctic: distinct diversity and core microbes in rhizosphere and endosphere compartments of the plant

A. Yerkhova — 2023-02-15

Plant microbiome plays a crucial role in the plants’ performance and fitness to the environment. The latter is especially significant for the plants withstanding the unfavorable conditions of the Antarctic. The study aimed to evaluate the microbiome of Antarctic pearlwort Colobanthus quitensis (Kunth) Bartl. growing in the wide range from the South Shetland Islands in the North to Marguerite Bay in the South (63°S – 68°S) in the maritime Antarctic. The composition of C. quitensis microbiome (rhizosphere and endophytes of the plant's aerial part) was studied by 16S rRNA amplicon metagenomic sequencing on Illumina Novaseq 6000. The number of operational taxonomic units and diversity indices (Shannon, Simpson, Faith PD) of the endosphere microbiomes were lower (p < 0.05) than in the rhizosphere microbiomes, and the ANOSIM test revealed a difference (R = 0.9, p = 0.0001) in the microbiomes’ taxonomic structure. The diversity of the barren’s microbiome was lower compared to the rhizospheres’. Proteobacteria, Acidobacteria, Actinobacteria, Bacteroidota, Chloroflexi, and Verrucomicrobia were dominant in the rhizosphere. Similar phyla were found in the barren, yet the ratio of Actinobacteria was higher. Proteobacteria dominated in the endosphere, followed by Firmicutes, Actinobacteria, and Bacteroidota. Alphaproteobacteria, Actinobacteria, and Acidobacteria represented a large proportion of the core microbiota of C. quitensis rhizosphere. The endophyte microbiome’s core was mainly composed of Alphaproteobacteria, Gammaproteobacteria, and Firmicutes. On the family taxonomic level, Rhodobacteraceae, Microbacteriaceae, Rhizobiaceae, Xanthobacteraceae, Sphingomonadaceae, Comamonadaceae, Pseudomonadaceae, and Oxalobacteraceae were determined as the core for rhizosphere and endosphere. The correlation was low (R = 0.22, p = 0.04)
between the rhizosphere microbiome composition and the latitude. Nevertheless, differential abundance of some bacterial taxa in the rhizosphere was attributed to the region of the plant’s growth: Northern, Central, or Southern part of the maritime Antarctic. The shift in the composition of microbial communities can be associated with the changing of the climatic conditions southwards along the Western coast of the Antarctic Peninsula.

Russian aggression against Ukraine: a new challenge facing Antarctic governance

A. Fedchuk — 2023-02-15

The Antarctic Treaty System has long been seen as an example of successful international cooperation for peace, research, and environmental protection for the benefit of all humanity. However, the military aggression of one Antarctic decision-making state against another has a destructive effect on the latter’s national Antarctic program resulting in a sequestered budget, a reduced research program, and a need to support the scientists threatened or displaced by the warfare. Such military aggression requires a consolidated response from the Antarctic community and challenges the Antarctic Treaty itself as an early and critical arms-control instrument and could undermine the ATS regime. This study examines the first individual and collective efforts to counter Russian full-scale military invasion of Ukraine since February 24, 2022, made by the international polar community, particularly during the highest annual international forum for the Antarctic governance – the 44th Antarctic Treaty Consultative Meeting, ATCM (Berlin, 2022). It is argued that this meeting saw an unprecedented deviation from almost 60 years of diplomatic practices by Antarctic Treaty Parties of controversy avoidance and use of imprecise language in their reports. In Berlin, there was the condemnation in the strongest possible terms of Russian unjustifiable, unprovoked, and illegal invasion of Ukraine. This démarche to the Russian delegation will necessarily affect the further work of other Antarctic-related administrative and advisory bodies within the Antarctic Treaty System. That includes ATCM’s observers and experts’ organisations such as the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), the Council of Managers of National Antarctic Programs (COMNAP), the Scientific Committee on Antarctic Research (SCAR), and the International Association of Antarctica Tour Operators (IAATO). It is expected that if the aggression continues, isolation measures such as international and national sanctions and institutional restrictions will be extended. In this case, further progress in rejecting any Russian initiatives and suspending ongoing joint projects with Russian partners will significantly complicate the diplomatic, research, fishery, and logistics activities of the Russian Federation within the Antarctic area until the situation allows for the resumption of cooperation.