Fronts, water masses and heat content variability in the Western Indian sector of the Southern Ocean during austral summer 2004
Two meridional CTD and XBT sections were covered along 45°E and 57°30’E to investigate the morphology of main fronts in the southwest Indian Ocean as a part of Indian pilot expedition to the Southern Ocean on board ORV Sagar Kanya. The frontal systems distinguish the different regimes of cold Antarc...
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ftnio:oai:dsr.nio.org:2264/522 2023-05-15T13:59:28+02:00 Fronts, water masses and heat content variability in the Western Indian sector of the Southern Ocean during austral summer 2004 AnilKumar, N. Luis, A.J. Somayajulu, Y.K. RameshBabu, V. Dash, M.K. Pednekar, S.M. Babu, K.N. Sudhakar, M. Pandey, P.C. 2006 916471 bytes application/pdf http://drs.nio.org/drs/handle/2264/522 en eng Elsevier An edited version of this paper was published by Elsevier. Copyright [2006] Elsevier Oceanic fronts Indian sector of Southern Ocean Heat content Thermohaline structure Article 2006 ftnio 2012-08-25T20:03:33Z Two meridional CTD and XBT sections were covered along 45°E and 57°30’E to investigate the morphology of main fronts in the southwest Indian Ocean as a part of Indian pilot expedition to the Southern Ocean on board ORV Sagar Kanya. The frontal systems distinguish the different regimes of cold Antarctic waters from the warmer and saltier waters of the subtropical regime. Along 57°30’E, the signature of the Subtropical Front (STF) was a rapid decrease in surface temperature from 17°C to 10.6°C between 43°50’S and 45°40’S and it was identified as a broad frontal region with a southward shift compared to that at 45°E. The Subantarctic Front (SAF) and Polar Front (PF) were also located with remarkable features noted in the literature. PF was identified between 48° and 52°S along 45°E, where the surface temperature reduced from 5.5 to 2.7°C and where the northern limit of sub-surface temperature minimum layer (<2°C) is extended. This study reveals a southward shift of the oceanic fronts (STF and SAF) from west to east, with a maximum southward displacement of ~4° latitude for STF. The thermocline region was absent south of PF. An enhancement in the mixed layer thickness from 42° to 52°S occurred in association with the strengthening of the wind forcing. The presents of major watermasses like Subtropical Surface Water, Subantarctic Surface Water, Mode Water, Antarctic Intermediate Water, Circumpolar Deep Water and Antarctic Bottom Water were identified along the 45°E meridional section. Upper-ocean heat-content computation revealed a remarkable drop of 989 ×107 J/m2 (~42°S) and 1405 × 107 J/m2 (~44°S) along 45° and 57°30’E, respectively. This sudden drop in heat content in turn affects the meridional heat transfer which is crucial for the studies related to global climatic variability. Article in Journal/Newspaper Antarc* Antarctic Southern Ocean National Institute of Oceanography, India: Digital Repository Service (DRS@nio) Antarctic Austral Indian Southern Ocean |
institution |
Open Polar |
collection |
National Institute of Oceanography, India: Digital Repository Service (DRS@nio) |
op_collection_id |
ftnio |
language |
English |
topic |
Oceanic fronts Indian sector of Southern Ocean Heat content Thermohaline structure |
spellingShingle |
Oceanic fronts Indian sector of Southern Ocean Heat content Thermohaline structure AnilKumar, N. Luis, A.J. Somayajulu, Y.K. RameshBabu, V. Dash, M.K. Pednekar, S.M. Babu, K.N. Sudhakar, M. Pandey, P.C. Fronts, water masses and heat content variability in the Western Indian sector of the Southern Ocean during austral summer 2004 |
topic_facet |
Oceanic fronts Indian sector of Southern Ocean Heat content Thermohaline structure |
description |
Two meridional CTD and XBT sections were covered along 45°E and 57°30’E to investigate the morphology of main fronts in the southwest Indian Ocean as a part of Indian pilot expedition to the Southern Ocean on board ORV Sagar Kanya. The frontal systems distinguish the different regimes of cold Antarctic waters from the warmer and saltier waters of the subtropical regime. Along 57°30’E, the signature of the Subtropical Front (STF) was a rapid decrease in surface temperature from 17°C to 10.6°C between 43°50’S and 45°40’S and it was identified as a broad frontal region with a southward shift compared to that at 45°E. The Subantarctic Front (SAF) and Polar Front (PF) were also located with remarkable features noted in the literature. PF was identified between 48° and 52°S along 45°E, where the surface temperature reduced from 5.5 to 2.7°C and where the northern limit of sub-surface temperature minimum layer (<2°C) is extended. This study reveals a southward shift of the oceanic fronts (STF and SAF) from west to east, with a maximum southward displacement of ~4° latitude for STF. The thermocline region was absent south of PF. An enhancement in the mixed layer thickness from 42° to 52°S occurred in association with the strengthening of the wind forcing. The presents of major watermasses like Subtropical Surface Water, Subantarctic Surface Water, Mode Water, Antarctic Intermediate Water, Circumpolar Deep Water and Antarctic Bottom Water were identified along the 45°E meridional section. Upper-ocean heat-content computation revealed a remarkable drop of 989 ×107 J/m2 (~42°S) and 1405 × 107 J/m2 (~44°S) along 45° and 57°30’E, respectively. This sudden drop in heat content in turn affects the meridional heat transfer which is crucial for the studies related to global climatic variability. |
format |
Article in Journal/Newspaper |
author |
AnilKumar, N. Luis, A.J. Somayajulu, Y.K. RameshBabu, V. Dash, M.K. Pednekar, S.M. Babu, K.N. Sudhakar, M. Pandey, P.C. |
author_facet |
AnilKumar, N. Luis, A.J. Somayajulu, Y.K. RameshBabu, V. Dash, M.K. Pednekar, S.M. Babu, K.N. Sudhakar, M. Pandey, P.C. |
author_sort |
AnilKumar, N. |
title |
Fronts, water masses and heat content variability in the Western Indian sector of the Southern Ocean during austral summer 2004 |
title_short |
Fronts, water masses and heat content variability in the Western Indian sector of the Southern Ocean during austral summer 2004 |
title_full |
Fronts, water masses and heat content variability in the Western Indian sector of the Southern Ocean during austral summer 2004 |
title_fullStr |
Fronts, water masses and heat content variability in the Western Indian sector of the Southern Ocean during austral summer 2004 |
title_full_unstemmed |
Fronts, water masses and heat content variability in the Western Indian sector of the Southern Ocean during austral summer 2004 |
title_sort |
fronts, water masses and heat content variability in the western indian sector of the southern ocean during austral summer 2004 |
publisher |
Elsevier |
publishDate |
2006 |
url |
http://drs.nio.org/drs/handle/2264/522 |
geographic |
Antarctic Austral Indian Southern Ocean |
geographic_facet |
Antarctic Austral Indian Southern Ocean |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_rights |
An edited version of this paper was published by Elsevier. Copyright [2006] Elsevier |
_version_ |
1766268016586129408 |