Ecological Safety of Coastal and Shelf Zones of Sea Ecological Safety of Coastal and Shelf Zones of Sea 2413-5577 20230302 Research Article Structure and Climatic Intra-Annual Variability of Water Mass Characteristics in the Powell Basin and on the Adjacent Antarctic Peninsula Shelf Artamonov Yu. V.
Russian Federation
artam-ant@yandex.ru Skripaleva E. A.
Russian Federation
sea-ant@yandex.ru Nikolskii N. V.
Russian Federation
nikolsky.geo@gmail.com Marine Hydrophysical Institute of RAS Sevastopol Russian Federation 25 09 2023 2023 3 22 39 29 04 2023 28 06 2023 18 05 2023 Copyright © 2023, Yu. V. Artamonov, E. A. Skripaleva, N. V. Nikolskii 2023 Yu. V. Artamonov, E. A. Skripaleva, N. V. Nikolskii https://creativecommons.org/licenses/by-nc/4.0/ https://ecological-safety.ru/en/repository/issues/2023/03/02/

The paper analyzes the long-term average structure and climatic intra-annual variability of water mass characteristics in the Powell Basin and adjacent water areas based on monthly average potential temperature and salinity data for each year from 1958 to 2021 from ECMWF ORA-S5 reanalysis. It is shown that the Antarctic Shelf Water is observed not only over the shallow shelf of the Joinville Archipelago, but also over the continental slope in the northwestern Weddell Sea. It is revealed that the layer of Circumpolar Deep Water is divided into Upper and Lower modifications. The Deep and Bottom Waters of the Weddell Sea do not appear as separate extremes on the long-term average θ,S-curves. It is shown that in the center of the cyclonic gyre in the Powell Basin, the Antarctic Winter Water core is located in a layer of 25-55 m. In the Scotia Sea, the Hesperides Trough, and over the Philip Ridge, the Antarctic Winter Water core deepens to 60-85 m. The minimum depths of the cores of the Upper and Lower modifications of the Circumpolar Deep Water (250-300 m and 500-600 m, respectively) are observed in the central part of the Powell Basin and closer to the center of the Weddell Sea Gyre, the maximum depths (1000-1300 m and 1100-1500 m, respectively) are observed over the slopes of the depths of the Joinville shelf and the South Scotia, Philip, and Joinville Ridges. It is shown that seasonal changes in the θ-index of the Antarctic Surface Water are maximum (3.5-4°C) in the southern Scotia Sea and in the Hesperides Trough. Seasonal changes in the S-index are maximum (1.8-1.9 PSU) over the Philip Ridge and in the northern and southern parts of the Powell Basin. Intra-annual changes in the θ,S-indices of the Antarctic Shelf Water reach 1.6-1.8°C and 1.5 PSU, respectively. The Weddell Sea Surface Water is characterized by weak changes in the θ-index, while changes in its S-index reach almost 1.8 PSU. Intra-annual changes in the θ,S-indices of Antarctic Winter Water are maximum in the central part of the Powell Basin (up to 1°C and 1.1 PSU).

 Southern Ocean Weddell Sea Powell Basin Antarctic shelf water masses potential water temperature salinity neutral density spatiotemporal variability vertical water structure The work was carried out under FSBSI FRC MHI state assignment FNNN-2021-0004 "Fundamental studies of oceanological processes which determine the state and evolution of the marine environment influenced by natural and anthropogenic factors, based on observation and modeling methods" ("Oceanological processes" code).

About the authors:

Yuri V. Artamonov, Leading Research Associate, Marine Hydrophysical Institute of RAS (2 Kapitanskaya St., Sevastopol, 299011, Russian Federation), Dr.Sci. (Geogr.), ResearcherID: AAC-6651-2020, artam-ant@yandex.ru

Elena A. Skripaleva, Senior Research Associate, Marine Hydrophysical Institute of RAS (2 Kapitanskaya St., Sevastopol, 299011, Russian Federation), Ph.D. (Geogr.), ResearcherID: AAC-6648-2020, sea-ant@yandex.ru

Nikolay V. Nikolskii, Junior Research Associate, Marine Hydrophysical Institute of RAS (2 Kapitanskaya St., Sevastopol, 299011, Russian Federation), ResearcherID: AAC-7723-2020, nikolsky.geo@gmail.com

Contribution of the authors:

Yuri V. Artamonov – general scientific supervision of the study, statement of the study aims and objectives, method development, qualitative analysis of the results and their interpretation, discussion of the work results, formulation of conclusions

Elena A. Skripaleva – review of literature on the study problem, qualitative analysis of the results and their interpretation, processing and description of the study results, discussion of the work results, formulation of conclusions, preparation of the manuscript, text refinement

Nikolay V. Nikolskii – development and debugging of computer programmes for data processing, algorithm programming, graph plotting, participation in discussion of the article materials

All the authors have read and approved the final manuscript.

Article text not included.

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