On How the Seasonal Variability of the ITCZ Drives Subtropical-Tropical Exchange in the Atlantic Ocean
2016 Ocean Sciences Meeting, 21-26 February 2016, New Orleans.-- 1 page, 7 figures The Inter-Tropical Convergence Zone (ITCZ) oscillates seasonally in the North Atlantic Ocean, its mean position moving between the Equator in February and 10°N in August-September. Further, during its annual march, th...
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ftcsic:oai:digital.csic.es:10261/161990 2024-02-11T10:06:22+01:00 On How the Seasonal Variability of the ITCZ Drives Subtropical-Tropical Exchange in the Atlantic Ocean Pelegrí, Josep Lluís Castellanos, Paola Emelianov, Mikhail Gasser, Marc Gourrion, Jérôme Peña-Izquierdo, Jesús Rosell Fieschi, Miquel 2016-02-22 http://hdl.handle.net/10261/161990 https://doi.org/10.13140/RG.2.1.1686.1843 unknown American Geophysical Union #PLACEHOLDER_PARENT_METADATA_VALUE# info:eu-repo/grantAgreement/MINECO/Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016/CTM2014-56987-P https://dx.doi.org/10.13140/RG.2.1.1686.1843 https://osm.agu.org/2016/scientific-program/ Sí doi:10.13140/RG.2.1.1686.1843 2016 Ocean Sciences Meeting http://hdl.handle.net/10261/161990 open póster de congreso http://purl.org/coar/resource_type/c_6670 2016 ftcsic https://doi.org/10.13140/RG.2.1.1686.1843 2024-01-16T10:28:59Z 2016 Ocean Sciences Meeting, 21-26 February 2016, New Orleans.-- 1 page, 7 figures The Inter-Tropical Convergence Zone (ITCZ) oscillates seasonally in the North Atlantic Ocean, its mean position moving between the Equator in February and 10°N in August-September. Further, during its annual march, the ITCZ remains oriented SW-NE, with 10° of latitude difference across the Atlantic. As a consequence, Ekman convergence-divergence changes zonally and seasonally, setting up the sea-surface absolute dynamic topography (ADT) that drives geostrophic currents in the tropical ocean and the adjacent subtropical gyres. The clearest example is the seasonal growth of the North Equatorial Counter Current (NECC) at 6-8°N, as an intense eastward jet in the tropical North Atlantic amid the westward South Equatorial Current (SEC). The NECC starts in the eastern Atlantic in May and progresses west, fed by a northern diversion of the SEC, until it reaches the western boundary in August, causing the retroflection of the North Brazil Current (NBC). The NECC results from the boreal-summer northward penetration of the ITCZ and the associated South Atlantic High: the surface winds cause zonal bands of meridional Ekman convergence (3-7°N) and divergence (7-13°N) that lead to a ridge-valley ADT pattern, with the NECC unfolding at those latitudes of large latitudinal ADT gradients (6-8°N). The NECC intensifies through input from the interior gyres - anticyclonic near the low-latitude ridge and cyclonic around the northern valley, the latter related to the northern subtropical cell - and only after August it fuels from the NBC retroflection. The northern position of the ITCZ prevents analogous jets and retroflections to occur in the southern hemisphere, yet the location where the SEC bifurcates (into the northward NBC and the southward Brazil Current) changes between January (8°S) and June (16°S). Further, between April and July, a ridge-valley ADT distribution appears in the western tropical South Atlantic, giving rise to ... Still Image North Atlantic Digital.CSIC (Spanish National Research Council) Orleans ENVELOPE(-60.667,-60.667,-63.950,-63.950) |
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Open Polar |
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Digital.CSIC (Spanish National Research Council) |
op_collection_id |
ftcsic |
language |
unknown |
description |
2016 Ocean Sciences Meeting, 21-26 February 2016, New Orleans.-- 1 page, 7 figures The Inter-Tropical Convergence Zone (ITCZ) oscillates seasonally in the North Atlantic Ocean, its mean position moving between the Equator in February and 10°N in August-September. Further, during its annual march, the ITCZ remains oriented SW-NE, with 10° of latitude difference across the Atlantic. As a consequence, Ekman convergence-divergence changes zonally and seasonally, setting up the sea-surface absolute dynamic topography (ADT) that drives geostrophic currents in the tropical ocean and the adjacent subtropical gyres. The clearest example is the seasonal growth of the North Equatorial Counter Current (NECC) at 6-8°N, as an intense eastward jet in the tropical North Atlantic amid the westward South Equatorial Current (SEC). The NECC starts in the eastern Atlantic in May and progresses west, fed by a northern diversion of the SEC, until it reaches the western boundary in August, causing the retroflection of the North Brazil Current (NBC). The NECC results from the boreal-summer northward penetration of the ITCZ and the associated South Atlantic High: the surface winds cause zonal bands of meridional Ekman convergence (3-7°N) and divergence (7-13°N) that lead to a ridge-valley ADT pattern, with the NECC unfolding at those latitudes of large latitudinal ADT gradients (6-8°N). The NECC intensifies through input from the interior gyres - anticyclonic near the low-latitude ridge and cyclonic around the northern valley, the latter related to the northern subtropical cell - and only after August it fuels from the NBC retroflection. The northern position of the ITCZ prevents analogous jets and retroflections to occur in the southern hemisphere, yet the location where the SEC bifurcates (into the northward NBC and the southward Brazil Current) changes between January (8°S) and June (16°S). Further, between April and July, a ridge-valley ADT distribution appears in the western tropical South Atlantic, giving rise to ... |
format |
Still Image |
author |
Pelegrí, Josep Lluís Castellanos, Paola Emelianov, Mikhail Gasser, Marc Gourrion, Jérôme Peña-Izquierdo, Jesús Rosell Fieschi, Miquel |
spellingShingle |
Pelegrí, Josep Lluís Castellanos, Paola Emelianov, Mikhail Gasser, Marc Gourrion, Jérôme Peña-Izquierdo, Jesús Rosell Fieschi, Miquel On How the Seasonal Variability of the ITCZ Drives Subtropical-Tropical Exchange in the Atlantic Ocean |
author_facet |
Pelegrí, Josep Lluís Castellanos, Paola Emelianov, Mikhail Gasser, Marc Gourrion, Jérôme Peña-Izquierdo, Jesús Rosell Fieschi, Miquel |
author_sort |
Pelegrí, Josep Lluís |
title |
On How the Seasonal Variability of the ITCZ Drives Subtropical-Tropical Exchange in the Atlantic Ocean |
title_short |
On How the Seasonal Variability of the ITCZ Drives Subtropical-Tropical Exchange in the Atlantic Ocean |
title_full |
On How the Seasonal Variability of the ITCZ Drives Subtropical-Tropical Exchange in the Atlantic Ocean |
title_fullStr |
On How the Seasonal Variability of the ITCZ Drives Subtropical-Tropical Exchange in the Atlantic Ocean |
title_full_unstemmed |
On How the Seasonal Variability of the ITCZ Drives Subtropical-Tropical Exchange in the Atlantic Ocean |
title_sort |
on how the seasonal variability of the itcz drives subtropical-tropical exchange in the atlantic ocean |
publisher |
American Geophysical Union |
publishDate |
2016 |
url |
http://hdl.handle.net/10261/161990 https://doi.org/10.13140/RG.2.1.1686.1843 |
long_lat |
ENVELOPE(-60.667,-60.667,-63.950,-63.950) |
geographic |
Orleans |
geographic_facet |
Orleans |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
#PLACEHOLDER_PARENT_METADATA_VALUE# info:eu-repo/grantAgreement/MINECO/Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016/CTM2014-56987-P https://dx.doi.org/10.13140/RG.2.1.1686.1843 https://osm.agu.org/2016/scientific-program/ Sí doi:10.13140/RG.2.1.1686.1843 2016 Ocean Sciences Meeting http://hdl.handle.net/10261/161990 |
op_rights |
open |
op_doi |
https://doi.org/10.13140/RG.2.1.1686.1843 |
_version_ |
1790604025689800704 |