Abstract
We analyze CTD and hydrochemical data from more than 30 oceanographic stations occupied during cruise 79 of the R/V Akademik Mstislav Keldysh (AMK-79) in January–February 2020. Sampling stations were organized into a spatial grid in the Powell Basin, Hesperides Trough, Phillip Ridge, Phillip Passage, South Orkney Plateau, and South Scotia Ridge. The paper includes preliminary results of the hydrological and hydrochemical research of water mass properties and their transformation in the region of Antarctic Bottom Water outflow. Three modifications of Warm Deep Water with various thermohaline and hydrochemical characteristics were observed in various parts of the Powell Basin; we suggest that they have dissimilar mechanisms of formation. We propose a concept of Weddell Sea Slope Water that is a result of the mixing of shelf waters formed in the Weddell Sea and Warm Deep Water over the slope south of the Joinville Ridge and research the hydrological role of its inflow into the Powell Basin. The admixture of Weddell Sea Slope Water to Weddell Sea Deep Water transforms water properties at depths of 1500–2500 m over the slope in the Powell Basin. Weddell Sea Deep Water is getting fresher, but colder and denser, than observed in the central deep part of the Powell Basin. We introduce a scheme of pathways of regional water masses based on the analysis of AMK-79 data, high-resolution historical CTD data from World Ocean Database 2018, and literature sources.
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References
Amblas D, Dowdeswell JA (2018) Physiographic influences on dense shelf-water cascading down the Antarctic continental slope. Earth-Sci Rev 185:887–900
Arhan M, Heywood KJ, King BA (1999) The deep waters from the Southern Ocean at the entry to the Argentine basin. Deep-Sea Res II 46(1–2):475–499
Boyer TP, Baranova OK, Coleman C, Garcia HE, Grodsky A, Locarnini RA, Mishonov AV, Paver CR, Reagan JR, Seidov D, Smolyar IV, Weathers K, Zweng MM (2018) World Ocean Database 2018. A.V. Mishonov, Technical Ed., NOAA Atlas NESDIS 87
Carmack EC, Foster TD (1975) On the flow of water out of the Weddell Sea. Deep-Sea Res 22:711–724
Deacon GER (1937) The hydrology of the Southern Ocean. Discov Rep 15:3–122
Fahrbach E, Rohardt G, Scheele N, Schroder M, Strass V, Wisotzki A (1995) Formation and discharge of deep and bottom water in the northwestern Weddell Sea. J Mar Res 53:5–538
Fahrbach E, Hoppema M, Rohardt G, Schroder M, Wisotzki A (2004) Decadal-scale variations of water mass properties in the deep Weddell Sea. Ocean Dyn 54:77–91
Flexas MM, Schodlok MP, Padman L, Menemenlis D, Orsi AH (2015) Role of tides on the formation of the Antarctic slope front at the Weddell-Scotia confluence. J Geophys Res Oceans 120:3658–3680
Foldvik A, Gammelsrod T, Torresen T (1985) Circulation and water masses on the southern Weddell Sea shelf. Antarctica Res Ser 43:5–20
Foster TD, Carmack EC (1976a) Frontal zone mixing and Antarctic bottom water formation in the southern Weddell Sea. Deep-Sea Res I 23:301–317
Foster TD, Carmack EC (1976b) Temperature and salinity structure in the Weddell Sea. J Phys Oceanogr 6:36–44
Franco BC, Mata MM, Piola AR, Garcia CAE (2007) Northwestern Weddell Sea deep outflow into the Scotia Sea during the austral summers of 2000 and 2001 estimated by inverse methods. Deep Sea Res I Oceanogr Res Pap 54(10):1815–1840
Gill AE (1973) Circulation and bottom water production in the Weddell Sea. Deep-Sea Res 20(2):111–140
Gordon AL (1971) Oceanography of Antarctic waters. In: Reid JL (ed) Antarctic oceanology I, Antarctic research series, 15. American Geophysical Union, Washington, DC, pp 205–221
Gordon AL (1998) Western Weddell Sea thermohaline stratification. In: Ocean ice and atmosphere: interactions at the antarctic continental margin, Antarctic research series 75. American Geophysical Union, Washington, DC, pp 215–240
Gordon AL, Visbeck M, Huber BA (2001) Export of Weddell Sea deep and bottom water. J Geophys Res 106(C5):9005–9018
Grosfeld K, Gerdes R, Determann J (1997) Thermohaline circulation and interaction between ice shelf cavities and the adjacent open ocean. J Geophys Res Oceans 102(C7):15595–15610
Heywood KJ, Naveira Garabato AC, Stevens DP, Muench RD (2004) On the fate of the Antarctic slope front and the origin of the Weddell front. J Geophys Res 109:C06021
Jackett DR, McDougall TJ (1997) A neutral density variable for the World’s oceans. J Geophys Res 27:237–263
McDougall TJ (1987) Neutral surfaces. J Phys Oceanogr 17:1950–1964
Middleton JH, Humphries SE (1989) Thermohaline structure and mixing in the region of Prydz Bay Antarctica. Deep-Sea Res 36:1255–1266
Miyake (1939) Chemical studies of the western Pacific Ocean I and II. The chemical composition of the oceanic salt parts 1 and 2. Bull Chem Soc Jpn 14(29–35):55–58
Muench RD, Gordon AL (1995) Circulation and transport of water along the western Weddell Sea margin. J Geophys Res 100(C9):18,503–18,515
Munk W, Wunsch C (1998) Abyssal recipes II: energetics of tidal and wind mixing. Deep-Sea Res 45:1977–2010
Naveira Garabato AC, Heywood KJ, Stevens DP (2002) Modification and pathways of Southern Ocean deep waters in the Scotia Sea. Deep Sea Res I 49:681–705
Orsi AH, Nowlin WD Jr, Whitworth T III (1993) On the circulation and stratification of the Weddell gyre. Deep-Sea Res I Oceanogr Res Pap 40:169–203
Orsi AH, Johnson GC, Bullister JL (1999) Circulation mixing and production of Antarctic bottom water. Prog Oceanogr 43:55–109
Orsi AH, William MSJ, Bullister JL (2002) On the total input of Antarctic waters to the deep ocean: a preliminary estimate from chlorofluorocarbon measurements. J Geophys Res 107(C8):31–31,22
Padman L, Howard SL, Muench RD (2006) Internal tide generation along the south Scotia ridge. Deep-Sea Res II Top Stud Oceanogr 53:157–171
Padman L, Muench RD, Howard S, Mueller R (2008) Tidal impacts on oceanographic and sea-ice processes in the Southern Ocean. American Geophysical Union, Fall Meeting, abstract id. OS13C-1208
Purkey SG, Johnson GS (2013) Antarctic bottom water warming and freshening: contributions to sea level rise, ocean freshwater budgets, and global heat gain. J Clim 26:6105–6122
Rintoul SR (2007) Rapid freshening of Antarctic bottom water formed in the Indian and Pacific oceans. Geophys Res Lett 34:L06606
Robertson R (2001) Internal tides and baroclinicity in the southern Weddell Sea: 1 model description. J Geophys Res Oceans 106(C11):27001–27016
Robertson R (2005) Baroclinic and barotropic tides in the Weddell Sea. Antarct Sci 17(03):461–474
Ruan X, Thompson AF, Flexas MM, Sprintall J (2017) Contribution of topographically generated submesoscale turbulence to Southern Ocean overturning. Nat Geosci 10(11):840–845
Thompson AF, Heywood KJ (2008) Frontal structure and transport in the northwestern Weddell Sea. Deep Sea Res I Oceanogr Res Pap 55(10):1229–1251
Thompson AF, Heywood KJ, Thorpe SE, Renner AHH, Trasviña (2009) A surface circulation at the tip of the Antarctic peninsula from drifters. J Phys Oceanogr 39:3–26
Von Gyldenfeldt AB, Fahrbach E, Garcı́a MA, Schröder M (2002) Flow variability at the tip of the Antarctic peninsula. Deep Sea Res II Top Stud Oceanogr 49(21):4743–4766
Weatherall P, Marks KM, Jakobsson M, Schmitt T, Tani S, Arndt JE, Rovere M, Chayes D, Ferrini V, Wigley R (2015) A new digital bathymetric model of the world’s oceans. Earth Space Sci 2:331–345. https://wwwgebconet/data_and_products/gridded_bathymetry_data/gebco_30_second_grid. The latest release of the GEBCO 30 arc-second global grid of elevations, GEBCO_2014 Grid, was published in 2014
Whitworth T III, Orsi AH, Kim SJ, Nowlin WD, Locarnini RA (1998) Water masses and mixing near the Antarctic slope front. In: Ocean ice and atmosphere: interactions at the Antarctic continental margin, Antarctic research series 75. American Geophysical Union, Washington, DC, pp 1–27
Whitworth T, Nowlin WD, Orsi AH, Locarnini RA, Smith SG (1994) Weddell Sea shelf water in the Bransfield Strait and Weddell-Scotia confluence. Deep-Sea Res I Oceanogr Res Pap 41:629–641
Wong APS, Riser SC (2013) Modified shelf water on the continental slope north of Mac Robertson land East Antarctica. Geophys Res Lett 40(23):6186–6190
Acknowledgments
The authors are grateful to S.A. Dobrolubov and E.G. Morozov for valuable comments to the paper and to the shipboard scientific-technical crew of the R/V Akademik Mstislav Keldysh for their help in collecting the data. The study was performed in the framework of the state assignment of Russia (theme No. 0128-2029-0008).
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Fedotova, A.A., Stepanova, S.V. (2021). Water Mass Transformation in the Powell Basin. In: Morozov, E.G., Flint, M.V., Spiridonov, V.A. (eds) Antarctic Peninsula Region of the Southern Ocean. Advances in Polar Ecology, vol 6. Springer, Cham. https://doi.org/10.1007/978-3-030-78927-5_8
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