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Niang C, Mancho AM, García-Garrido VJ, Mohino E, Rodriguez-Fonseca B, Curbelo J. Transport pathways across the West African Monsoon as revealed by Lagrangian Coherent Structures. Sci Rep 2020; 10:12543. [PMID: 32719398 PMCID: PMC7385109 DOI: 10.1038/s41598-020-69159-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 06/23/2020] [Indexed: 11/17/2022] Open
Abstract
The West African Monsoon (WAM) system is the main source of rainfall in the agriculturally based region of the Sahel. Understanding transport across the WAM is of crucial importance due to the strong impact of humidity and dust pathways on local cloud formation. However, the description of this transport is challenging due to its 3D complex nature. Lagrangian Coherent Structures (LCS) simplify transport description across the WAM by providing a geometrical partition of the troposphere into domains. Air parcels within each domain have similar dynamical characteristics. LCS make it possible to achieve an integrated vision of transport pathways across this system. Using this approach we unveil new connections in the WAM system. In particular, we identify transport pathways between the Tropical Easterly Jet (TEJ) and the African Easterly Jet (AEJ). Furthermore, the clockwise circulation associated with the divergent upper part of the Sahara heat low is clearly delimitated. Additionally, we show the presence of mixing regions in the AEJ and the lower part of the TEJ that are linked to pathways to sources of dust and humidity.
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Affiliation(s)
- Coumba Niang
- Instituto de Ciencias Matemáticas, Consejo Superior de Investigaciones Científicas (CSIC), C/ Nicolás Cabrera 15, Campus de Cantoblanco, 28049, Madrid, Spain.,Laboratoire de Physique de l'Atmosphére et de l'Océan Simón Fongang (LPAO-SF), Ecole Supérieure Polytechnique (ESP), Université Cheikh Anta Diop, BP 5085, Dakar-Fann, Senegal
| | - Ana Maria Mancho
- Instituto de Ciencias Matemáticas, Consejo Superior de Investigaciones Científicas (CSIC), C/ Nicolás Cabrera 15, Campus de Cantoblanco, 28049, Madrid, Spain.
| | | | - Elsa Mohino
- Departamento de Fisica de la Tierra y Astrofisica, Universidad Complutense de Madrid (UCM), Madrid, Spain
| | - Belén Rodriguez-Fonseca
- Departamento de Fisica de la Tierra y Astrofisica, Universidad Complutense de Madrid (UCM), Madrid, Spain
| | - Jezabel Curbelo
- Instituto de Ciencias Matemáticas, Consejo Superior de Investigaciones Científicas (CSIC), C/ Nicolás Cabrera 15, Campus de Cantoblanco, 28049, Madrid, Spain.,Departament de Matemàtiques, Universitat Politècnica de Catalunya (UPC), 08028, Barcelona, Spain
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Liu Y, Lu M, Yang H, Duan A, He B, Yang S, Wu G. Land–atmosphere–ocean coupling associated with the Tibetan Plateau and its climate impacts. Natl Sci Rev 2020; 7:534-552. [PMID: 35273806 PMCID: PMC8906512 DOI: 10.1093/nsr/nwaa011] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Revised: 01/27/2020] [Accepted: 01/31/2020] [Indexed: 11/12/2022] Open
Abstract
This paper reviews recent advances regarding land–atmosphere–ocean coupling associated
with the Tibetan Plateau (TP) and its climatic impacts. Thermal forcing over the TP
interacts strongly with that over the Iranian Plateau, forming a coupled heating system
that elevates the tropopause, generates a monsoonal meridional circulation over South Asia
and creates conditions of large-scale ascent favorable for Asian summer monsoon
development. TP heating leads to intensification and westward extension (northward
movement) of the South Asian High (Atlantic Intertropical Convergence Zone), and exerts
strong impacts on upstream climate variations from North Atlantic to West Asia. It also
affects oceanic circulation and buoyancy fields via atmospheric stationary wave trains and
air–sea interaction processes, contributing to formation of the Atlantic Meridional
Overturning Circulation. The TP thermal state and atmospheric–oceanic conditions are
highly interactive and Asian summer monsoon variability is controlled synergistically by
internal TP variability and external forcing factors.
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Affiliation(s)
- Yimin Liu
- State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences (CAS), Beijing 100029, China
- College of Earth Science, University of Chinese Academy of Sciences, Beijing 100049, China
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100101, China
| | - Mengmeng Lu
- School of Atmospheric Sciences & Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies, Sun Yat-sen University, Guangzhou 510275, China
- Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Haijun Yang
- Laboratory for Climate and Ocean-Atmosphere Studies (LaCOAS) and Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing 100871, China
| | - Anmin Duan
- State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences (CAS), Beijing 100029, China
- College of Earth Science, University of Chinese Academy of Sciences, Beijing 100049, China
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100101, China
| | - Bian He
- State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences (CAS), Beijing 100029, China
- College of Earth Science, University of Chinese Academy of Sciences, Beijing 100049, China
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100101, China
| | - Song Yang
- School of Atmospheric Sciences & Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies, Sun Yat-sen University, Guangzhou 510275, China
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519080, China
| | - Guoxiong Wu
- State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences (CAS), Beijing 100029, China
- College of Earth Science, University of Chinese Academy of Sciences, Beijing 100049, China
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