Mechanisms controling the sea surface temperature and precipitation anomalies during contrasted years, 2010 and 2012, in the tropical Atlantic
The Atlantic Marine ITCZ (AMI) is a regional manifestation of the ITCZ over the warm water of the tropical Atlantic oceans. Few studies have been devoted to document the processes driving the evolution of the SST and precipitation, most of which were centered on the eastern side of the basin. The pr...
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Other Authors: | , , , , , , , |
Format: | Doctoral or Postdoctoral Thesis |
Language: | English |
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HAL CCSD
2019
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Online Access: | https://theses.hal.science/tel-02498758 https://theses.hal.science/tel-02498758/document https://theses.hal.science/tel-02498758/file/2019TOU30010B.pdf |
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ftutoulouse3hal:oai:HAL:tel-02498758v1 |
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record_format |
openpolar |
institution |
Open Polar |
collection |
Université Toulouse III - Paul Sabatier: HAL-UPS |
op_collection_id |
ftutoulouse3hal |
language |
English |
topic |
Oceanic mixed-layer budget Atmospheric water budget Tropical Atlantic Regional modeling Bilan de chaleur dans la couche de mélange océanique Bilan d'eau atmosphérique Atlantique tropical Modélisation régionale [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology |
spellingShingle |
Oceanic mixed-layer budget Atmospheric water budget Tropical Atlantic Regional modeling Bilan de chaleur dans la couche de mélange océanique Bilan d'eau atmosphérique Atlantique tropical Modélisation régionale [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology Vasconcelos Nogueira Neto, Antonio Mechanisms controling the sea surface temperature and precipitation anomalies during contrasted years, 2010 and 2012, in the tropical Atlantic |
topic_facet |
Oceanic mixed-layer budget Atmospheric water budget Tropical Atlantic Regional modeling Bilan de chaleur dans la couche de mélange océanique Bilan d'eau atmosphérique Atlantique tropical Modélisation régionale [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology |
description |
The Atlantic Marine ITCZ (AMI) is a regional manifestation of the ITCZ over the warm water of the tropical Atlantic oceans. Few studies have been devoted to document the processes driving the evolution of the SST and precipitation, most of which were centered on the eastern side of the basin. The present study provides an analysis of the evolution of the ocean and the atmosphere over the Western part of the Atlantic for two contrasted years in Sea Surface Temperature (SST), 2010 and 2012, that were respectively the warmest and coldest years observed during the 1982-2015 period. The causes of interannual and seasonal anomalies of SST are first explored via an oceanic mixed-layer (ML) heat budget performed from Argo floats, satellite-based data and ERAI-Interim atmospheric reanalysis for the period 2007-2012. The surface latent heat flux was found to be under-estimated by 20 W/m2 and conducted to erroneous vertical mixing in the whole domain. Correction of these surface fluxes yielded to residuals which were assimilated to vertical turbulent mixing at the mixed-layer base, which fell into realistic range. Once corrected, the ML budget shows that the observed SST anomalies in 2010 and 2012 were generated by anomalous wind stress and, consequently, anomalous latent heat flux in the north Atlantic during winter. The wind-induced horizontal advection plays a fundamental role in balancing the surface flux in the south Atlantic in 2012. The north tropical Atlantic appears as a key region for the generation of the SSTs pattern observed in 2010 and 2012. The second part of the study analyses the building of the 2010 and 2012 rainfall anomalies and the underlying mechanisms. On seasonal average, 2010 shows a more intense rainfall over the basin while 2012 exhibits a meridional dipole of precipitation with a rainfall maximum shifted 5 degrees north of its climatological location. An analysis of the water budget integrated vertically indicates that the anomalous vertical advection of moisture is the leading term that ... |
author2 |
Centre national de recherches météorologiques (CNRM) Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP) Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS) Université Paul Sabatier - Toulouse III Hervé Giordani Philippe Peyrille |
format |
Doctoral or Postdoctoral Thesis |
author |
Vasconcelos Nogueira Neto, Antonio |
author_facet |
Vasconcelos Nogueira Neto, Antonio |
author_sort |
Vasconcelos Nogueira Neto, Antonio |
title |
Mechanisms controling the sea surface temperature and precipitation anomalies during contrasted years, 2010 and 2012, in the tropical Atlantic |
title_short |
Mechanisms controling the sea surface temperature and precipitation anomalies during contrasted years, 2010 and 2012, in the tropical Atlantic |
title_full |
Mechanisms controling the sea surface temperature and precipitation anomalies during contrasted years, 2010 and 2012, in the tropical Atlantic |
title_fullStr |
Mechanisms controling the sea surface temperature and precipitation anomalies during contrasted years, 2010 and 2012, in the tropical Atlantic |
title_full_unstemmed |
Mechanisms controling the sea surface temperature and precipitation anomalies during contrasted years, 2010 and 2012, in the tropical Atlantic |
title_sort |
mechanisms controling the sea surface temperature and precipitation anomalies during contrasted years, 2010 and 2012, in the tropical atlantic |
publisher |
HAL CCSD |
publishDate |
2019 |
url |
https://theses.hal.science/tel-02498758 https://theses.hal.science/tel-02498758/document https://theses.hal.science/tel-02498758/file/2019TOU30010B.pdf |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
https://theses.hal.science/tel-02498758 Climatology. Université Paul Sabatier - Toulouse III, 2019. English. ⟨NNT : 2019TOU30010⟩ |
op_relation |
NNT: 2019TOU30010 tel-02498758 https://theses.hal.science/tel-02498758 https://theses.hal.science/tel-02498758/document https://theses.hal.science/tel-02498758/file/2019TOU30010B.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1810464882685902848 |
spelling |
ftutoulouse3hal:oai:HAL:tel-02498758v1 2024-09-15T18:24:31+00:00 Mechanisms controling the sea surface temperature and precipitation anomalies during contrasted years, 2010 and 2012, in the tropical Atlantic Mécanismes contrôlant les anomalies de température de surface de la mer et de précipitation au cours de deux années contrastées 2010 et 2012 dans l'Atlantique tropical Vasconcelos Nogueira Neto, Antonio Centre national de recherches météorologiques (CNRM) Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP) Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS) Université Paul Sabatier - Toulouse III Hervé Giordani Philippe Peyrille 2019-03-06 https://theses.hal.science/tel-02498758 https://theses.hal.science/tel-02498758/document https://theses.hal.science/tel-02498758/file/2019TOU30010B.pdf en eng HAL CCSD NNT: 2019TOU30010 tel-02498758 https://theses.hal.science/tel-02498758 https://theses.hal.science/tel-02498758/document https://theses.hal.science/tel-02498758/file/2019TOU30010B.pdf info:eu-repo/semantics/OpenAccess https://theses.hal.science/tel-02498758 Climatology. Université Paul Sabatier - Toulouse III, 2019. English. ⟨NNT : 2019TOU30010⟩ Oceanic mixed-layer budget Atmospheric water budget Tropical Atlantic Regional modeling Bilan de chaleur dans la couche de mélange océanique Bilan d'eau atmosphérique Atlantique tropical Modélisation régionale [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology info:eu-repo/semantics/doctoralThesis Theses 2019 ftutoulouse3hal 2024-06-25T00:17:23Z The Atlantic Marine ITCZ (AMI) is a regional manifestation of the ITCZ over the warm water of the tropical Atlantic oceans. Few studies have been devoted to document the processes driving the evolution of the SST and precipitation, most of which were centered on the eastern side of the basin. The present study provides an analysis of the evolution of the ocean and the atmosphere over the Western part of the Atlantic for two contrasted years in Sea Surface Temperature (SST), 2010 and 2012, that were respectively the warmest and coldest years observed during the 1982-2015 period. The causes of interannual and seasonal anomalies of SST are first explored via an oceanic mixed-layer (ML) heat budget performed from Argo floats, satellite-based data and ERAI-Interim atmospheric reanalysis for the period 2007-2012. The surface latent heat flux was found to be under-estimated by 20 W/m2 and conducted to erroneous vertical mixing in the whole domain. Correction of these surface fluxes yielded to residuals which were assimilated to vertical turbulent mixing at the mixed-layer base, which fell into realistic range. Once corrected, the ML budget shows that the observed SST anomalies in 2010 and 2012 were generated by anomalous wind stress and, consequently, anomalous latent heat flux in the north Atlantic during winter. The wind-induced horizontal advection plays a fundamental role in balancing the surface flux in the south Atlantic in 2012. The north tropical Atlantic appears as a key region for the generation of the SSTs pattern observed in 2010 and 2012. The second part of the study analyses the building of the 2010 and 2012 rainfall anomalies and the underlying mechanisms. On seasonal average, 2010 shows a more intense rainfall over the basin while 2012 exhibits a meridional dipole of precipitation with a rainfall maximum shifted 5 degrees north of its climatological location. An analysis of the water budget integrated vertically indicates that the anomalous vertical advection of moisture is the leading term that ... Doctoral or Postdoctoral Thesis North Atlantic Université Toulouse III - Paul Sabatier: HAL-UPS |