Spatial Structure and Intra-Annual Variability of Weddell Sea Front based on the Data of NOAA OISST Reanalysis

Yu. V. Artamonov, E. A. Skripaleva*, N. V. Nikolsky

Marine Hydrophysical Institute of RAS, Sevastopol, Russia

* e-mail: sea-ant@yandex.ru

Abstract

Based on the NOAA OISST reanalysis data, the spatial structure of the Weddell Sea Front in the climatic field of the sea surface temperature was analyzed and the seasonal variability of front’s characteristics was estimated. The spatial position of the frontal zone in the Weddell Sea was analyzed using distributions of the total horizontal temperature gradient. The characteristics of the front (the position of the gradients' extrema corresponding to the front, their magnitude and temperature on the front axis) were determined for each month on the profiles of meridional and zonal temperature gradients along meridians and parallels with a discreteness of 2.5° of longitude and 0.25° of latitude. It is shown that the interaction of Weddell Sea cold waters, which are transported by currents northward along the Antarctic Peninsula coasts, with the warmer waters of the eastern shelf of the Antarctic Peninsula and the Bransfield Strait surface water causes formation of two branches of the Weddell Sea Front. These branches round from a vast shelf at the Antarctic Peninsula tip and the Joinville archipelago the south and north and are traced further east along the boundaries of the bottom rise located approximately between 62.5S and 64.5S. To the south of the South Orkney Islands shelf, the two branches merge into one front, which follows to the east along the depth dump of the relative shallow between the South Orkney and South Sandwich Islands. In the seasonal cycle of the Weddell Sea Front intensity, a time lag was revealed of the front intensification period in the direction from west to east. In Bransfield Strait the front is most intense in February, between the Antarctic Peninsula tip and the South Orkney Islands – in March, east of the South Orkney Islands – in April. The branch of the Weddell Sea Front off the northeastern of the Antarctic Peninsula coasts intensifies in November – January, in the western part of the water area east of the James Ross and Snow Hill Islands – in January – February.

Keywords

Southwest Antarctica, Weddell Sea, sea surface temperature, intra-annual variability, horizontal temperature gradients, Weddell Sea Front

Acknowledgments

Еhe work is performed under State Order no. 0555-2019-0003 "Experimental studies of the variability of hydrophysical, hydrochemical and bio-optical fields at different spatio-temporal scales to identify the features of climatic changes in oceanographic conditions in the Atlantic part of Antarctica".

For citation

Artamonov, Yu.V., Skripaleva, E.A. and Nikolsky, N.V., 2020. Spatial Structure and Intra-Annual Variability of Weddell Sea Front based on the Data of NOAA OISST Reanalysis. Ecological Safety of Coastal and Shelf Zones of Sea, (4), pp. 89–102. doi:10.22449/2413-5577-2020-4-89-102 (in Russian).

DOI

10.22449/2413-5577-2020-4-89-102

References

  1. Maslennikov, V.V., 2003. Climatic Variability and Marine Ecosystem of the Antarctic. Moscow: VNIRO Publishing, 295 p. (in Russian).
  2. Sokolov, S. and Rintoul, S.R., 2007. On the Relationship between Fronts of the Antarctic Circumpolar Current and Surface Chlorophyll Concentrations in the Southern Ocean. Journal of Geophysical Research: Oceans, 112(C7), C07030. doi:10.1029/2006JC004072
  3. Venables, H., Meredith, M.P., Atkinson, A. and Ward, P., 2012. Fronts and Habitat Zones in the Scotia Sea. Deep-Sea Research Part II: Topical Studies in Oceanography, 59–60, pp. 14–24. doi:10.1016/j.dsr2.2011.08.012
  4. Lohmann, R. and Belkin, I.M., 2014. Organic Pollutants and Ocean Fronts across the Atlantic Ocean: A Review. Progress in Oceanography, 128, pp. 172–184. doi:10.1016/j.pocean.2014.08.013
  5. Chapman, C.C., Lea, M.-A., Meyer, A., Sallée, J.-B. and Hindell,  M., 2020. Defining Southern Ocean fronts and their influence on biological and physical processes in a changing climate. Nature Climate Change, 10(3), pp. 209–219. doi:10.1038/s41558-020-0705-4
  6. Shulgovskiy, K.E., 2005. [Large-Scale Variability of Oceanological Conditions in the Western Part of the Atlantic Sector of the Antarctic and its Influence on the Distribution of Krill]. Kaliningrad: AtlantNIRO, 160 p. (in Russian).
  7. Arzhanova, N.V. and Artamonova, K.V., 2014. Hydrochemical Structure of Water Masses in Areas of the Antarctic Krill (Euphausia Superba Dana) Fisheries. In: VNIRO, 2014. Trudy VNIRO. Moscow: VNIRO Publishing House. Vol. 152, pp. 118–132 (in Russian).
  8. Gordon, A.L., Georgi, D.T. and Taylor, H.W., 1977. Antarctic Polar Front Zone in Western Scotia Sea – Summer 1975. Journal of Physical Oceanography, 7(3), pp. 309–328. doi:10.1175/1520-0485(1977)0070309:APFZIT2.0.CO;2
  9. Peterson, R.G. and Stramma, L., 1991. Upper-level Circulation in the South Atlantic Ocean. Progress in Oceanography, 26(1), pp. 1–73. doi:10.1016/0079-6611(91)90006-8
  10. Niller, P.P., Amos, A. and Hu, J-H., 1991. Water Masses and 200 m Relative Geostrophic Circulation in the Western Bransfield Strait Region. Deep Sea Research Part A. Oceanographic Research Papers, 38(8–9), pp. 943–959. doi:10.1016/0198-0149(91)90091-S
  11. Artamonov, Yu., Romanov, A., Vnukov, Yu., Perov, A. and Stepura, I., 2003. Results of the Oceanographycal Research at the Western Bransfield Strait during March 2002. Ukrainian Antarctic Journal, (1), pp. 7–16 (in Russian).
  12. Artamonov, Yu.V., 2002. Features of the Hydrological Structure of the Confluence Zone of the Weddell and Scotia Seas in the Summer of the Southern Hemisphere. In: MHI, 2002. Monitoring Systems of Environment. Sevastopol: MHI. Iss. 4, pp. 371–380 (in Russian).
  13. Artamonov, Yu.V., Bulgakov, N.P., Lomakin, P.D., Skripaleva, E.A., Artamonov, A.Yu. and Stanichnii, S.V., 2005. Structure and Seasonal Variability of Large-Scale Fronts in the Southwestern Atlantic and Adjacent Basins of the Antarctica Based on Hydrological and Satellite Data. Oceanology, 45(5), pp. 617–630.
  14. Artamonov, Yu.V. and Skripaleva, E.A., 2005. The Structure and Seasonal Variability of the Large-Scale Fronts in the Atlantic Ocean on the Basis of Satellite Data. Issledovaniye Zemli iz Kosmosa, (4), pp. 62–75 (in Russian).
  15. Artamonov, Yu.V., Lomakin, P.D. and Skripaleva, E.A., 2008. Seasonal and Interannual Variability of the Characteristics of Scotia-Sea Front Based on the Satellite Measurements of Sea-Surface Temperature. Physical Oceanography, 18(1), pp. 52–62. doi:10.1007/s11110-008-9009-3
  16. Zhou, M., Zhu, Yi., Dorland, R.D. and Measures, C.I., 2010. Dynamics of the Current System in the Southern Drake Passage. Deep-Sea Research Part I: Oceanographic Research Papers, 57(9), pp. 1039–1048. doi:10.1016/j.dsr.2010.05.012
  17. Reynolds, R.W., Smith, T.M., Liu, C., Chelton, D.B., Casey, K.S. and Schlax, M.G., 2007. Daily High-Resolution-Blended Analyses for Sea Surface Temperature. Journal of Climate, 20(22), pp. 5473–5496. doi:10.1175/2007JCLI1824.1
  18. Richardson, P.L. and McKee, T.K., 1984. Average Seasonal Variation of the Atlantic Equatorial Currents from Historical Ship Drifts. Journal of Physical Oceanography, 14(7), pp. 1226–1238. doi:10.1175/1520-0485(1984)0141226:ASVOTA2.0.CO;2
  19. Rintoul, S.R., Donguy, J.R. and Roemmich, D.H., 1997. Seasonal Evolution of Upper Ocean Thermal Structure between Tasmania and Antarctica. Deep-Sea Research Part I: Oceanographic Research Papers, 44(7), pp. 1185–1202. doi:10.1016/s0967-0637(96)00125-2
  20. Morrow, R., Brut, A. and Chaigneau, A., 2003. Seasonal and Interannual Variations of the Upper Ocean Energetics between Tasmania and Antarctica. Deep Sea Research Part I: Oceanographic Research Papers, 50(3), pp. 339–356. doi:10.1016/S0967-0637(03)00015-3
  21. Kazmin, A.S., 2016. Persistent Thermal Fronts in the Black Sea: Existence, Variability, and Response to Atmospheric Forcing. Oceanology, 56(3), pp. 336–341. doi:10.1134/S0001437016030115

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