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Influence of Ross Sea Bottom Water Changes on the Warming and Freshening of the Antarctic Bottom Water in the Australian-antarctic Basin : Volume 8, Issue 4 (09/07/2012)

By Shimada, K.

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Book Id: WPLBN0004020585
Format Type: PDF Article :
File Size: Pages 14
Reproduction Date: 2015

Title: Influence of Ross Sea Bottom Water Changes on the Warming and Freshening of the Antarctic Bottom Water in the Australian-antarctic Basin : Volume 8, Issue 4 (09/07/2012)  
Author: Shimada, K.
Volume: Vol. 8, Issue 4
Language: English
Subject: Science, Ocean, Science
Collections: Periodicals: Journal and Magazine Collection, Copernicus GmbH
Publication Date:
Publisher: Copernicus Gmbh, Göttingen, Germany
Member Page: Copernicus Publications


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Ohshima, K. I., Shimada, K., Aoki, S., & Rintoul, S. R. (2012). Influence of Ross Sea Bottom Water Changes on the Warming and Freshening of the Antarctic Bottom Water in the Australian-antarctic Basin : Volume 8, Issue 4 (09/07/2012). Retrieved from

Description: Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan. Changes to the properties of Antarctic Bottom Water in the Australian-Antarctic Basin (AA-AABW) between the 1990s and 2000s are documented using data from the WOCE Hydrographic Program (WHP) and repeated hydrographic surveys. Strong cooling and freshening are observed on isopycnal layers denser than Γn = 28.30 kg m−3. Changes in the average salinity and potential temperature below this isopycnal correspond to a basin-wide warming of 1300 ± 200 GW and freshening of 24 ± 3 Gt year−1. Recent changes to dense shelf water in the source regions in the Ross Sea and George V Land can explain the freshening of AA-AABW but not its extensive warming. An alternative mechanism for this warming is a decrease in the supply of AABW from the Ross Sea (RSBW). Hydrographic profiles between the western Ross Sea and George V Land (171–158° E) were analyzed with a simple advective-diffusive model to assess the causes of the observed changes. The model suggests that the warming of RSBW observed between the 1970s and 2000s can be explained by a 21 ± 23% reduction in RSBW transport and the enhancement of the vertical diffusion of heat resulting from a 30 ± 7% weakening of the abyssal stratification. The documented freshening of Ross Sea dense shelf water leads to a reduction in both salinity and density stratification. Therefore the direct freshening of RSBW at its source also produces an indirect warming of the RSBW. A simple box model suggests that the changes in RSBW properties and volume transport (a decrease of 6.7% is assumed between the year 1995 and 2005) can explain 51 ± 6% of the warming and 84 ± 10% of the freshening observed in AA-AABW.

Influence of Ross Sea Bottom Water changes on the warming and freshening of the Antarctic Bottom Water in the Australian-Antarctic Basin

Aoki, S., Rintoul, S. R., Ushio, S., Watanabe, S., and Bindoff, N. L.: Freshening of the Adélie Land Bottom Water near 140° E, Geophys. Res. Lett., 32, L23601, doi:10.1029/2005GL024246, 2005.; Bindoff, N. L. and McDougall, T. J.: Diagnosing Climate Change and Ocean Ventilation Using Hydrographic Data, J. Phys. Oceanogr., 24, 1037–1152, 1994.; Broecker, W. S.: Thermohaline circulation, the Achilles heel of our climate system: Will man-made CO2 upset the current balance?, Science, 278, 1582–1588, 1997.; Boyer, T. P., Antonov, J. I., Baranova, O. K., Garcia, H. E., Johnson, D. R., Locarnini, R. A., Mishonov, A. V., O'Brien, T. D., Seidov, D., Smolyar, I. V., and Zweng, M. M.: World Ocean Database 2009, edited by: Levitus, S., NOAA Atlas NESDIS 66, US Gov. Printing Office, Wash., D.C., 216 pp., DVDs, 2009.; Fer, I.: Scaling turbulent dissipation in an Arctic fjord, Deep-Sea Res. II, 53, 77–95, 2006.; Fukamachi, Y., Wakatsuchi, M., Taira, K., Kitagawa, S., Ushio, S., Takahashi, A., Oikawa, K., Furukawa, T., Yoritaka, H., Fukuchi, M., and Yamanouchi, T.: Seasonal variability of bottom water properties off Adélie Land, Antarctica, J. Geophys. Res., 105, 6531–6540, 2000.; Fukamachi, Y., Rintoul, S. R., Church, J. A., Aoki, S., Sokolov, S., Rosenberg, M. A., and Wakatsuchi, M.: Strong export of Antarctic Bottom Water east of the Kerguelen plateau, Nat. Geosci., 3, 327–331, doi:10.1038/ngeo842, 2010.; Gargett, A. E. and Holloway, G.: Dissipation and diffusion by internal wave breaking, J. Marine Res., 42, 15–27, 1984.; Gordon, A., Zambianchi, E., Orsi, A., Visbeck, M., Giulivi, C., Whitworth, T., and Spezie, G.: Energetic plumes over thewestern Ross Sea continental slope, Geophys. Res. Lett., 31, L21302, doi:10.1029/2004GL020785, 2004.; Gordon, A., Orsi, A., Muench, R., Huber, B., Zambianchi, E., and Visbeck, M.: Western Ross Sea continental slope gravity currents, Deep-Sea Res. II, 56, 796–817, 2009.; Gregg, M. C.: Scaling turbulent dissipation in the thermocline, J. Geophys. Res., 94, 9686–9698, 1989.; Jacobs, S. S.: Bottom water production and its links with the thermohaline circulation, Antarct. Sci., 16, 427–437, 2004.; Orsi, A. H. and Wiederwohl, C. L.: A recount of Ross Sea waters, Deep-Sea Res. II, 56, 778–795, 2009.; Jacobs, S. S.: Observations of change in the Southern Ocean, Philos. T. R. Soc. A., 364, 1657–1681, doi:10.1098/rsta.2006.1794, 2006.; Jacobs, S. S. and Giulivi, C. F.: Large Multidecadal Salinity Trends near the Pacific-Antarctic Continental Margin, J. Climate, 23, 4508–4524, 2010.; Jacobs, S. S., Giulivi, C. F., and Mele, P. A.: Freshening of the Ross Sea during the late 20th century, Science, 297, 386–389, 2002.; Johnson, G. C., Purkey, S. G., and Bullister, J. L.: Warming and Freshening in the Abyssal Southeastern Indian Ocean, J. Climate, 21, 5351–5363, 2008.; Kawano, T., Doi, T., Uchida, H., Kouketsu, S., Fukasawa, M., Kawai, Y., and Katsumata, K.: Heat Content Change in the Pacific Ocean between the 1990s and 2000s, Deep-Sea Res. II, 57, 1141–1151, 2009.; Kunze, E., Firing, E., Hummon, J. M., Chereskin, T. K., and Thurnherr, A. M.: Global Abyssal Mixing Inferred from Lowered ADCP Shear and CTD Strain Profiles, J. Phys. Oceanogr., 36, 1553–1576, 2006.; Kusahara, K., Hasumi, H., and Williams, G. D.: Impact of the Mertz Glacier Tongue calving on dense water formation and export, Nature Communications, 2, 159, doi:10.1038/ncomms1156, 2011.; Ledwell, J. R., Watson, A. J., and Law, C. S.: Mixing of a tracer in the pycnocline, J. Geophys. Res., 103, 21499–21529, 1998.; Levitus, S., Antonov, J., and Boyer, T.: Warming of the world ocean, 1955–2003, Geophys. Res. Lett., 32, L23601,


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