Antarctic Research Institute Research Articles

Drifting long-lived. To the 50ʰᵗ anniversary of the opening of the “North Pole-22” station

The national drifting station “North Pole-22” (NP-22 or SP-22) had been opened on September 13, 1973 in the Arctic on the big ice island and operated for 3130 days. Now it is the longest operating observational station in the history of Arctic studies of the USSR and the Russian Federation. For eight and a half years, its total drift amounted 17,069 km. During that period a wide complex of scientific programs in oceanography, geophysics, meteorology, glaciology, hydrography, hydrobiology was carried out here. In addition, field tests and implementation of new types of scientific instruments and introduction of new expeditionary polar equipment into the observation practice were performed. For the first time in the practice of the drifting NP/SP stations, oblique sounding of the ionosphere, observations of fine thermohaline structure of waters of the active layer of the Arctic Ocean were carried out. Geographical coordinates of the station drift were determined using Soviet satellite navigation systems; a complex for recording satellite images of the ice cover was deployed; investigations of the arctic ecosystems were made. Specific experiments were conducted aimed at the natural decomposition of heavy hydrocarbons by the ultraviolet solar radiation. The ice airfield of this station received 1,511 flights of aircraft and helicopters, delivering 2,961 tons of expedition cargos. Landings on this airfield were provided by flight teams of the High-Latitude Air Expedition “Sever” of the Arctic and Antarctic Research Institute and the Hydrographic Service of the Northern Fleet. Foreign specialists repeatedly visited the station. For the nine rotations of polar explorers who worked at the NP/SP-22, its personnel amounted to 249 people, many of them several times worked at this drifting station in different years. The work of the NP/SP-22 team was appreciated by the government authorities of the USSR.

Построение безопасных коридоров судоходства в морях арктического шельфа на основе использования алгоритмов глубокого обучения

A comparative analysis of interannual changes in the ice coverage of the Pechora and the Kara Seas has been conducted based on the information of open sources (satellite observations) gathered by the Arctic and Antarctic Research Institute and the open dataset with mapped ice conditions ArcticDEM. The following problems of the study have been solved: the analysis of the most common approaches to building a forecast based on the analysis of ice conditions has been conducted; a deep learning algorithm to solve the problem of analysis of ice fields has been developed and tested; a medium-term forecast of the condition of ice fields in the area of the Pechora and the Kara Seas has been prepared based on the approbation model example; the obtained results have been analyzed and processed. In the course of study, an algorithm of automated mapping of ice conditions based on the satellite imagery data has been developed; the possibilities of its application to forecast ice conditions automatically, i.e., without using a manmade mapping, have been described. It has been demonstrated that the use of images based on multiple spectral bands and the combination of data from different satellites can minimize the influence of clouds and weather conditions. The model gave the real forecasting accuracy for a period of 10–14 weeks equal to 49–53 % for the Barents (Pechora) and the Kara Seas of 2018–2021. In case the model was fine-tuned and included data from the Barents (Pechora) and Kara Seas before 2018 in the training sample, the accuracy on the data after 2018 increased up to 52–56 %. The feature of the model is its ability to operate with different classes of ice and precisely determine its amount. The developed method increases the efficiency of operational control over the ice conditions in the Arctic seas. Safe navigation routes for shipping transport in the Pechora Sea have been modeled.

СЕЗОННЫЕ И МЕЖГОДОВЫЕ ИЗМЕНЕНИЯ ВОЗРАСТНОЙ СТРУКТУРЫ ЛЕДЯНОГО ПОКРОВА ГРЕНЛАНДСКОГО МОРЯ В ЗИМНИЙ ПЕРИОД

Seasonal and interannual changes in the Greenland Sea ice age composition during winter months for seven standard age categories are analyzed. To estimate the amount of the ice of different age categories, the digital archive of the region’s ice charts for the period 1997-2022 produced by the Arctic and Antarctic Research Institute is used. Statistical insignificance of linear trends has been revealed for the main age categories of the Greenland Sea ice. A comparison of the obtained estimates of the variability in the amount of the ice of different age categories and earlier studies shows that the quantitative changes in the Greenland Sea ice age composition started before 1997. The data on the ice age composition over a 25-year observation period alone are insufficient to draw an unambiguous conclusion about a decrease in the Greenland Sea ice thickness.

Development of the method of special ship ice observations

Since the middle of the XXth century researchers at the Arctic and Antarctic Research Institute (AARI) have been carrying out special ship ice observations in the Arctic and other freezing seas. Field data about main sea ice parameters are necessary for developing and validation of sea ice forecasts and satellite information. In keeping with technological advances and new research and practical tasks this method is ever developing. In spring 2023 sea ice observations were organized by the AARI’s reseachers onboard the nuclear icebreaker 50 let Pobedy in the south-western part of the Kara Sea. This paper presents recommendations concerning the method of special ship ice observations as developed during the expedition: dispatch to the vessel of operative and forecast hydrometeorological information from the AARI with a request for return transfer to the AARI of the processing results of the data obtained in the areas of predicted high deformation of ice cover along the route of navigation and upgrade of the ship television complex to receive information about ice layers and structure.

Features of Formation of the Lena Polynya on the Estuarine Coast of the Bykovsky Arm in the Summer

Based on the results of the global oceanic reanalysis (GLORYS12.v.1), materials of hydrometeorological observations of the Roshydromet network in the Laptev Sea and the mouth of the Lena River, reviews of the ice processes in the Arctic Ocean by the Arctic and Antarctic Research Institute, this paper considers the features of the evolution of the Lena Polynya on the estuarine coast of the Bykovsky Arm in the warm period 1993–2019. The relationship between the timing of the formation of a polynya on the seashore of this arm with the dates of the beginning of the flood at the top of the Lena River delta has been revealed. The assumption is confirmed that the average growth rate of the Lena polynya in summer is determined by the timing of its formation – the earlier the flood begins, the earlier the polynya forms on the coast of the Bykovsky arm and the smaller the average rate its growth. It has been established that the process of warming in the mouth area of the Lena in 2008–2019 stabilized, as there are no significant trends in the characteristics of water and ice regimes. These regularities may be invariant for other mouths of the rivers of the Laptev Sea basin, and the obtained dependences can be used to improve the forecast of the dates of cleansing of the water area at the estuary seashore of the Lena from ice and planning icebreaking navigation along the route Tiksi port–Lena River.

Экспериментально-аналитическая методика определения глобальной ледовой нагрузки от ледовых сжатий на суда и плавучие платформы, используемые в качестве полярных дрейфующих обсерваторий

The article considers the problem of determining global ice loads from ice compression on ships, icebreakers, floating platforms used as bases for drifting Arctic research stations. The author solves the task of forecasting ice loads during operation by combining mathematical methods and physical modeling in the ice tank. As a result, an experimental-analytical method for modeling ice compression in an ice tank has been obtained. The basic part of the technique is a new mathematical model that describes the physical processes that accompany the quasi-static interaction of a floating object with inclined sides in the middle part of the hull with a thick one-year or multi-year ice field. The experimental part of the methodology is a special technology for conducting serial model tests in an ice tank, which makes it possible to use the developed mathematical model to assess the ice loads under ice compression. The author considers the application of a new modeling technique on the example of the ice-resistant self-propelled platform “North Pole”. The results of the assessment of the global ice load based on the data of a series of model tests carried out in the Arctic and Antarctic Research Institute (AARI) ice tank are presented.

Cavity Mode Wave Frequency Variation Associated With Inward Motion of the Magnetopause During Interplanetary Shock Compression

AbstractA cavity mode wave, referring to a trapped or radially standing fast mode wave between different magnetospheric boundaries, has been developed in theory and reported in observation studies. In this study, we present an interplanetary shock (IPS)‐induced cavity mode wave event observed outside the plasmasphere on 31 August 2017 with multispacecraft measurements. The phase delay of 90° between the azimuthal electric field and compressional magnetic field indicates that the fast‐mode wave triggered by the IPS is a standing wave, presumably radially trapped in the cavity between the magnetopause and plasmapause. Taking advantage of the location of Van Allen Probe B spacecraft right outside the plasmapause and the Arctic and Antarctic Research Institute ground‐based high‐latitude array mapped in the noon sector, it is suggested that the observed compressional wave associates to cavity mode with its inner boundary at the plasmapause and its outer boundary at the magnetopause. The peak frequency of the wavelet spectrum of the compressional magnetic field increases from 10.5 to 12.5 mHz, which is consistent with the theoretically calculated cavity eigenfrequencies before and after the IPS. We also provide the first evidence that the peak frequency of the cavity mode increases due to the inward motion of the magnetopause during IPS compression.

North Pole ice-resistant self-propelled platform as an innovative complex for research in the Arctic

The Russian presence in the Arctic Region and the development of the Arctic is one of the most important geopolitical interests of Russia. At the beginning of the 21st century, the problem of using innovative methods in Arctic research came to the fore. Based on the analysis of the unique work experience of drifting stations “Severniy Polus” (“North Pole”) (1937-2015), Arctic and Antarctic Research Institute specialists have concluded that the stations should be replaced by a modern scientific complex, capable of solving a wider range of problems. As a result, it was proposed to create an ice-resistant self-propelled platform (IRSPP) – an engineering structure for permanent basing of scientific observatories. The IRSPP is designed to conduct year-round comprehensive scientific research in the high latitudes of the Arctic Ocean and should make a long drift of at least one year together with the surrounding ice massive. The scientific complex of the IRSPP includes 16 different laboratories, including an ice load monitoring laboratory. A unique ice load monitoring system (ILMS) has been developed for the IRSPP. The ILMS will be an essential part of the system of safe operation and persistence of the IRSPP and will provide the platform hull with a measurement tool for studying the mechanics of deformation and destruction of sea ice in its interaction with the engineering structures. In all respects, the IRSPP is unparalleled in the world. Its use can open a new chapter in the exploration of the Russian Arctic and in international collaboration aimed at studying the northern latitudes. The platform was put into operation in 2022.

ИССЛЕДОВАНИЯ ПО ТЕМЕ «КРИАЛЬ» В ЭКСПЕДИЦИИ «СЕВЕРНЫЙ ПОЛЮС-41»

The expedition “North Pole-41” of the Arctic and Antarctic Research Institute on an ice-resistant self-propelled platform has started work in the central Arctic basin. The expedition program is designed for year-round studies of the natural environment, patterns and causes of changes in the climate system and biodiversity. The biological component of the expedition program “Cryal” of the Shirshov Institute of Oceanology of the Russian Academy of Sciences is aimed at studying the spatial and temporal characteristics of the water-ice environment and the species composition of ice and plankton communities in the central regions of the Arctic Ocean.

ВОСПОМИНАНИЯ О МАРИИ ПЕТРОВНЕ НЕСТЕРОВОЙ (1917–2002) И АНАЛИТИЧЕСКОЙ ЛАБОРАТОРИИ

In 2022, the 105th anniversary of the birth of Maria Petrovna Nesterova – a geochemist, Candidate of Technical Sciences, corresponding member of the Scientific Committee, was celebrated ACOPS, laureate of the USSR Council of Ministers Award (1985). In 1942, M. P. Nesterova went to the front as a volunteer, returned to study in 1944, became interested in Ocean research. M. P. Nesterova worked in the laboratory of the trust “Arktikrazvedka” Glavsevmorput and participated in Arctic expeditions to search for oil, uranium and other minerals. In 1954–1958 she was the head of the laboratory of the trust “Arktikrazvedka”, which in 1954 became part of the Arctic and Antarctic Research Institute (AARI). In 1968, the Laboratory became a part of the Shirshov Institute of Oceanology of the Academy of Sciences.

Wintertime Emissivities of the Arctic Sea Ice Types at the AMSR2 Frequencies

The surface effective emissivities of Arctic sea ice are calculated using Advanced Microwave Scanning Radiometer 2 (AMSR2) measurements. These emissivities are analyzed for stable winter conditions during the months of January–May and November and December of 2020 for several main sea ice types defined with the sea ice maps of the Arctic and Antarctic Research Institute (AARI). The sea ice emissivities are derived from the AMSR2 data using the radiation transfer model for a non-scattering atmosphere and ERA5 reanalysis data. The emissivities are analyzed only for areas of totally consolidated sea ice of definite types. Probability distribution functions are built for the emissivities and their functions for such sea ice types as nilas, young ice, thin first-year (FY) ice, medium FY ice, thick FY ice and multi-year ice. The emissivity variations with frequency are estimated for each of the considered sea ice type for all seven months. The variations are calculated both for the emissivities and for their gradients at the AMSR2 channel frequencies. Obtained emissivities turned out to be generally lower than reported previously in scientific studies, whereas the emissivity variability values proved to be much larger than was known before. For all FY ice types, at all the frequencies, an increase in the emissivity at the beginning of winter and its decrease by the end of May are observed. The emissivity gradients demonstrate noticeable decreases with sea ice age, and their values may be used in sea ice classification algorithms based on the AMSR2 data.

Reply to Comment by Troshichev et al. on “The Use of Invalid Polar Cap South (PCS) Indices in Publications”

AbstractThe publication by Stauning (2022b, 10.1029/2022JA030355): “The use of invalid Polar Cap South (PCS) indices in publications.” Journal of Geophysical Research: Space Physics, 127, e2022JA030355 is based on values of the PCS indices derived at the Arctic and Antarctic Research Institute (AARI) by the authors of the Comment and made available at the web portal maintained by the International Service of Geomagnetic Indices (ISGI) supported by the International Association for Geomagnetism and Aeronomy and also at the web portal maintained by AARI. One PCS version (“pre‐2021PCS”) comprises a series of indices spanning 1997–2021 published by AARI up to December 2021 and by ISGI up to April 2022. Since no other PCS version has been in play at AARI prior to 2021, this version, labeled “provisional” by ISGI, was beyond doubt used in the 9 publications listed in the commented publication by Stauning (2022b, 10.1029/2022JA030355). A modified PCS version (“post‐2021PCS”) was published by AARI in December 2021 and recently by ISGI (May 2022). The pre‐2021PCS version has been proven invalid by many examples of unfounded excessive index excursions and also by comparisons with indices of the post‐2021PCS index version. Its devaluating imprints on the publications issued by AARI between 2014 and 2021 are indisputable regardless of later modifications of the PCS index series.

Ice age composition in the Barents sea

The paper presents the key results of investigating Barents Sea ice age composition during the winter season, from the beginning of ice formation in October to its termination in May. To analyze the seasonal and interannual changes in the amount of ice of different age categories, we used ice charts for the Barents Sea for the period 1997–2021, produced by the Arctic and Antarctic Research Institute. The age composition of the ice cover in the Barents Sea is represented by seven standard ice categories (thickness ranges). The areas of ice of different age categories were calculated for a ten-day time interval (in percentage of the total ice area). The results are provided for three parts of the Barents Sea: western, northeastern and southeastern.The interannual changes in the amount of ice in relative fractions of ice of different age categories in the ice cover of the Barents Sea do not show significant trends for the period 1997–2021. Thus, with the observed reduction in the Barents Sea total ice area, the amount of ice of different age categories ranges within the limits of its own natural variability. Therefore, it is impossible to draw a definite conclusion about a decrease in ice cover thickness in the Barents Sea based only on data on the ice age composition over a 24-year period of observations analyzed in this study. On comparing the estimates obtained in this study of the age structure of the ice cover in the Barents Sea with those of the previous studies on this subject, we can argue that its average thickness at the beginning of the 21st century decreased, compared to the period 1971–1976. Taking into account the statistical insignificance of the trends in interannual variations in the amount of ice of different age gradations, one can maintain that quantitative changes in the age structure of the Barents Sea ice cover began earlier than 1997.

Mapping the thickness of sea ice in the Arctic as an example of using data from a ship-based television complex for operational hydrometeorological support of maritime activities

Sea ice charts produced by the ice services of the world are among the most widely used sources of information about sea ice conditions in the Arctic. The absolute majority of sea ice charts are based on visual expert analysis of satellite imagery accompanied by auxiliary data including ground information from coastal stations and ships navigating the Northern Sea Route (NSR). Ground measurements of sea ice thickness are necessary for validating the results of satellite imagery interpretation. Shipboard observations are highly valuable because, unlike coastal stations, the ships provide information about sea ice cover straight on the navigational routes, not in the coastal areas of land-fast ice, where the thickness values are not fully representative of the ice in the open sea. However, the current system of shipboard observations used by commercial fleets often does not meet the reliability requirements due to the human factor involved in the process of data collection. In the early 2000s, the Arctic and Antarctic Research Institute (AARI) suggested a new methodology for shipboard ice thickness measurement. A ship-based television complex (STC) was developed in order to exclude the human factor and standardize observations. The inaccuracy value was estimated as 3.8 % of the real thickness. By 2018, STC had been upgraded to a new ship-based television meteorological complex (STMC) allowing continuous automatic measurement of ice thickness and many other related hydrometeorological parameters during the entire voyage. The automatic and autonomous operation of the new equipment allows placing it on board the ship without the need for an ice specialist to be permanently present. It means that STMC can be used by commercial fleets, which constantly increase the number of Arc7 ice class vessels they use. For economic reasons, reinforced ice class vessels, whose number is growing, represent the only available infrastructure suitable for the deployment of distributed network providing operational hydrometeorological monitoring on the NSR. A comparison of STC data with AARI ice charts has revealed that real-time transmission of STC data from ships to the ice service office could increase the accuracy of ice charts and, as a consequence, the quality of the entire system of hydrometeorological informational support of maritime activities in the Arctic.

Подготовка изданий Водного кадастра по Арктической зоне Российской Федерации как составляющая обеспечения техносферной безопасности

Purpose: To assess the state and to identify the problems of preparing materials for the publication of the Water Cadastre for the Arctic zone of the Russian Federation. Methods: Analysis of information received by the Arctic and Antarctic Research Institute from the Murmansk, Northern, Ob-Irtysh, Central Siberian, Yakutsk and Chukotka hydrometeorological departments. Results: It is shown that the state of preparation of the Water Cadastre publications and the quality of published observations on the territory of the Arctic zone of the RF do not meet set regulatory requirements. This negatively affects the results of engineering calculations for hydrological support of economic activity in the region and, as a result, may reduce the level of technospheric safety in the Arctic. Practical significance: The results obtained made it possible to formulate the requirements for improving work efficiency in the preparation of publications of the Water Cadastre for water objects of the RF Arctic zone.

The Use of Invalid Polar Cap South (PCS) Indices in Publications

AbstractPolar Cap (PC) indices, PCN North based on magnetic observations from Qaanaaq (THL) in Greenland and PCS South based on magnetic data from Vostok in Antarctica, are very useful indices for studies of solar wind‐magnetosphere interactions and for space weather monitoring and forecasts. PCN indices are issued from the Danish Space Research Institute (DTU Space) while PCS indices are issued from the Arctic and Antarctic Research Institute (AARI) in St Petersburg. Unfortunately, series of invalid PCS values have been provided from AARI and used in a number of publications issued since the PC index concept was endorsed by the International Association of Geomagnetism and Aeronomy (IAGA) in 2013. In spite of the disclosure of the failure in the PCS indices in 2018, publishing at the IAGA‐supported International Service of Geomagnetic Indices of the invalid indices has continued up to now (2022). The present contribution defines the invalidating features of the PCS indices in question, conveys examples, and discusses the applications in peer‐reviewed publications.

Assessing the influence of meteorological parameters on sea ice area and thickness variability in the Kara Sea

The reduction of the sea ice area in the Arctic is one of the most notable consequences of climate change, with the Kara Sea contributing about 5 % to the overall reduction. The aim of this study is to assess the impact of changes in climatic conditions on the reduction of the area and thickness of the sea ice in the Kara Sea and the possibility of using the established dependencies for climate forecasting. The article provides quantitative estimates of the relationship between interannual changes in the sea ice thickness and sea ice extent in the Kara Sea and climate changes in the region and the remote influence of the sea surface temperature in the tropical North Atlantic for 1979–2019. The paper uses observation data obtained at meteorological stations, ERA5 reanalysis and data on the sea ice extent from the Arctic and Antarctic Research Institute website. In summer, the melting of sea ice is largely due to changes in the surface air temperature (correlation coefficient from –0.57 to –0.91). In winter, the ice thickness depends on the sum of frost degree-days (r = –0.80). The temperature regime, in turn, is determined by the radiation balance, namely, by the variability in the long-wave flow due to the increase in the water vapor content. On the basis of the relationships established, a linear regression model is proposed for forecasting the sea ice area with a lead time of about three months. The model is effective and statistically significant. The paper considers the remote influence of the sea surface temperature anomalies in the North Atlantic tropics on the ice coverage of the Kara Sea. The response of the sea ice extent to the sea surface temperature in the low latitudes is 30–34 months late. The significant correlation between the anomalies can serve as a basis for predicting the sea ice area in the Kara Sea with a lead time of up to three years.

The Polar Cap (PC) Index: PCS Version Based on Dome‐C Data

AbstractThe standard polar cap (PC) indices, PCN (North) based on magnetic data from Qaanaaq in Greenland and PCS (South) based on data from Vostok in Antarctica, have been submitted from the Arctic and Antarctic Research Institute in St. Petersburg, Russia, the Danish Meteorological Institute, and the Danish Space Research Institute in different versions. In order to consolidate PCS indices based on Vostok data or replace poor or missing index data, derivation procedures have been developed to generate alternative PCS index values based on data from Dome Concordia (Dome‐C) magnetic observations from epoch 2009–2020 of solar cycle 24. The reference levels and calibration parameters needed for calculations of Dome‐C‐based PCS values in post‐event and real‐time versions are defined and explained in the present work. Assessments of the new PCS index have shown its unprecedented high relevance. Part of the methods used here, such as the quiet reference level construction and the correlation and regression procedures used for calculations of scaling parameters, deviate from corresponding features considered inadequate of the International Association for Geomagnetism and Aeronomy‐endorsed PC index derivation methods.

Пространственно-временна́я изменчивость гидрохимических показателей водной среды Обской и Тазовской губ

The Gulf of Ob and Taz Bay are components of a special geographical object — Ob-Tar estuarine area. They are intensively used by companies, which produce natural gas and oil in the Yamal Region. The aim of the study is to assess the spatial patterns and temporal dynamics of the priority hydrochemical characteristics of the Gulf of Ob and Taz Bay. The data of the Arctic estuarine expeditions (1968—1989) and complex expeditions (2012—2013), organized by the Arctic and Antarctic Research Institute, are used as the research materials The authors have analyzed hydrochemical characteristics: pH, salinity, dissolved oxygen, silicon and phosphorus compounds. In summer-autumn period 2012—2013 there was a significant seawater intrusion to the south of the Gulf of Ob, caused by a small runoff of rivers the in these dry years. Dissolved oxygen distribution is determined by seasonal variability. In summer-autumn period the average values of more than 7 mg/l were observed. In winter, in the southern part of Gulf of Ob and Taz Bay there was an extreme oxygen deficit, dissolved oxygen values dropped below 1 mg/l. A tendency for a decrease in the content of silicon and phosphorus compounds from south to north was noted. Concentrations of phosphorus-containing compounds in the whole water area were low. The condition of Taz Bay and southern part of the Gulf of Ob is mainly determined by the river runoff and the hydrochemical regime in the area. In the period of high waters the regime has features inherent to rivers, and in the period of low flows — to lakes and reservoirs. Large-scale interference in the ecosystem of Ob-Taz estuarine area recently requires regular hydrological-ecological observations at coastal stations and along the water area sections.

Methods of snowmelt calculation in the Antarctic oasis Larsemann Hills

The paper studies the validity of snowmelt calculation methods, which are mostly used in hydrology, for the Larsemann Hills oasis (East Antarctica). The study bases on snow surveys data obtained on catchments of Low Lake, Reid Lake and Stepped Lake during the 65th season of the Russian Antarctic Expedition (RAE) in 2019-2020. Materials of the fond of Arctic and Antarctic Research Institute (AARI) are also used: snow surveys data collected on the catchment of Stepped Lake during the 57th RAE season in 2012 and on catchments of Low Lake, Reid Lake, Scandrett Lake and Stepped Lake during the 62th RAE season in 2017. Considered three methods of snowmelt calculation were derived by Kuz'min P.P., Popov E.G., Vinogradov Yu.B. Results of calculation are compared with snowmelt value obtained according to snow surveys. The paper shows two variants of calculations: in the first albedo of snow is determined from function of snow age as different values for each day, in the second albedo is determined from remote sensing data as average value for all period. Results of snowmelt calculation depend on the method which sets value of snow albedo: relative inaccuracies of results obtained of all discussed methods are smaller when albedo is determined as average value. The equation by Kuz'min P.P. gives the smallest inaccuracies of snowmelt calculation results in relative to real snowmelt values estimated from snow survey data. This snowmelt calculation method in the majority of cases reviewed gives satisfactory results and should be recommended for estimation of snowmelt values for this Antarctic territory.