A late Holocene paleoclimate reconstruction from Boqueirão Lake sediments, northeastern Brazil

Autor: Bruno Turcq, Abdelfettah Sifeddine, L. S. Moreira, Renato Campello Cordeiro, João Cláudio Cerqueira Viana, Ana Luiza Spadano Albuquerque, Doriedson Ferreira Gomes
Přispěvatelé: Departamento de Geoquimica, Universidade Federal Fluminense [Rio de Janeiro] (UFF), Biogéochimie-Traceurs-Paléoclimat (BTP), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD [France-Nord]), Departamento de Botânica, Universidade Federal da Bahia (UFBA), ANR-10-BLAN-0608,ELPASO,El-Niño : leçons du passé à partir de simulations et d'observations(2010), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636))
Jazyk: angličtina
Rok vydání: 2014
Předmět:
Zdroj: Repositório Institucional da UFBA
Universidade Federal da Bahia (UFBA)
instacron:UFBA
Palaeogeography, Palaeoclimatology, Palaeoecology
Palaeogeography, Palaeoclimatology, Palaeoecology, Elsevier, 2014, 415 (no spécial), pp.117-126. ⟨10.1016/j.palaeo.2014.07.010⟩
Palaeogeography, Palaeoclimatology, Palaeoecology, 2014, 415 (no spécial), pp.117-126. ⟨10.1016/j.palaeo.2014.07.010⟩
ISSN: 0031-0182
DOI: 10.1016/j.palaeo.2014.07.010
Popis: Texto completo: acesso restrito. p.117–126 Submitted by Edileide Reis (leyde-landy@hotmail.com) on 2015-03-24T13:12:06Z No. of bitstreams: 1 João Cláudio Cerqueira Viana.pdf: 1213757 bytes, checksum: 9d96af306e113f5477a5f9eda05605f2 (MD5) Approved for entry into archive by Alda Lima da Silva (sivalda@ufba.br) on 2015-03-27T20:16:54Z (GMT) No. of bitstreams: 1 João Cláudio Cerqueira Viana.pdf: 1213757 bytes, checksum: 9d96af306e113f5477a5f9eda05605f2 (MD5) Made available in DSpace on 2015-03-27T20:16:54Z (GMT). No. of bitstreams: 1 João Cláudio Cerqueira Viana.pdf: 1213757 bytes, checksum: 9d96af306e113f5477a5f9eda05605f2 (MD5) Previous issue date: 2014 Lake level fluctuations and environmental changes during the late Holocene were inferred from changes in sedimentology, bulk and isotope organic geochemistry, and a diatom based transfer function in a sediment core from Boqueirão Lake, northeast Brazil. The age-depth model was established using fifteen AMS 14C dates. Lake water level began increasing about AD 400, and reached its maximum during the Medieval Climate Anomaly (MCA), AD ~ 900–1100. Low lake water level was recorded during the Little Ice Age (LIA), AD ~ 1400–1820, which allowed macrophyte development in the littoral zone that was recorded by high Corg/Ntotal ratios. Considerable lake level variability was evident during the Current Warm Period (CWP). Humid/dry conditions in northeast Brazil during MCA/LIA, respectively, are related to the southward shift of Inter-Tropical Convergence Zone (ITCZ) during austral summer and fall. Those conditions contrast with records of a decrease/increase in the South American Summer Monsoon (SASM) during these periods. This observation also contrasts with paleoclimate inferences from the circum-Caribbean region indicating a northward shift of the ITCZ northern hemisphere summer position during the MCA and a southward shift during the LIA. We suggest that these shifts in ITCZ seasonality were higher during the MCA and smaller during the LIA. Our aim was to answer whether the zonal atmospheric circulation cell between the Amazon and northeast Brazil was responsible for antiphasing with the SASM. A strong monsoon over South America during the LIA reinforced convection upon Amazon, increasing the northeast low in the upper troposphere and large-scale subsidence over northeast Brazil and the Atlantic Ocean leading to a northward repositioning of the South Atlantic Subtropical Anticyclone. These factors in combination may have limited the southward seasonal shift of ITCZ, and they must have been responsible for drier conditions in northeast Brazil during the LIA.
Databáze: OpenAIRE
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