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The Tibetan Plateau Uplift is Crucial for Eastward Propagation of Madden-Julian Oscillation

The Tibetan Plateau (TP) and Himalayas have been treated as an essential external factor in shaping Asian monsoon and mid-latitude atmospheric circulation. In this study we perform numerical experiments with different uplift altitudes using the Nanjing University of Information Science and Technolog...

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Autores principales: Yang, Young-Min, Lee, June-Yi, Wang, Bin
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6820537/
https://www.ncbi.nlm.nih.gov/pubmed/31664057
http://dx.doi.org/10.1038/s41598-019-51461-w
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author Yang, Young-Min
Lee, June-Yi
Wang, Bin
author_facet Yang, Young-Min
Lee, June-Yi
Wang, Bin
author_sort Yang, Young-Min
collection PubMed
description The Tibetan Plateau (TP) and Himalayas have been treated as an essential external factor in shaping Asian monsoon and mid-latitude atmospheric circulation. In this study we perform numerical experiments with different uplift altitudes using the Nanjing University of Information Science and Technology Earth System Model to examine potential impacts of uplift of the TP and Himalayas on eastward propagation of the MJO and the associated mechanisms. Analysis of experimental results with dynamics-based MJO diagnostics indicates two potential mechanisms. First, the uplift considerably enhances low-level mean westerlies in the Indian Ocean and convection in the Maritime Continent, which in turn strengthens boundary layer moisture convergence (BLMC) to the east of the MJO convective center. The increased BLMC reinforces upward transport of moisture and heat from BL to free atmosphere and increases lower tropospheric diabatic heating by shallow and congestus clouds ahead of the MJO center, enhancing the Kelvin-Rossby wave feedback. Second, the uplift increases upper tropospheric mean easterlies and stratiform heating at the west of the MJO center, which contributes to eastward propagation of MJO by generating positive moist static energy at the east of MJO center. This study will contribute to a better understanding of the origin of the MJO and improvement in simulation of MJO propagation.
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spelling pubmed-68205372019-11-04 The Tibetan Plateau Uplift is Crucial for Eastward Propagation of Madden-Julian Oscillation Yang, Young-Min Lee, June-Yi Wang, Bin Sci Rep Article The Tibetan Plateau (TP) and Himalayas have been treated as an essential external factor in shaping Asian monsoon and mid-latitude atmospheric circulation. In this study we perform numerical experiments with different uplift altitudes using the Nanjing University of Information Science and Technology Earth System Model to examine potential impacts of uplift of the TP and Himalayas on eastward propagation of the MJO and the associated mechanisms. Analysis of experimental results with dynamics-based MJO diagnostics indicates two potential mechanisms. First, the uplift considerably enhances low-level mean westerlies in the Indian Ocean and convection in the Maritime Continent, which in turn strengthens boundary layer moisture convergence (BLMC) to the east of the MJO convective center. The increased BLMC reinforces upward transport of moisture and heat from BL to free atmosphere and increases lower tropospheric diabatic heating by shallow and congestus clouds ahead of the MJO center, enhancing the Kelvin-Rossby wave feedback. Second, the uplift increases upper tropospheric mean easterlies and stratiform heating at the west of the MJO center, which contributes to eastward propagation of MJO by generating positive moist static energy at the east of MJO center. This study will contribute to a better understanding of the origin of the MJO and improvement in simulation of MJO propagation. Nature Publishing Group UK 2019-10-29 /pmc/articles/PMC6820537/ /pubmed/31664057 http://dx.doi.org/10.1038/s41598-019-51461-w Text en © The Author(s) 2019 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Article
Yang, Young-Min
Lee, June-Yi
Wang, Bin
The Tibetan Plateau Uplift is Crucial for Eastward Propagation of Madden-Julian Oscillation
title The Tibetan Plateau Uplift is Crucial for Eastward Propagation of Madden-Julian Oscillation
title_full The Tibetan Plateau Uplift is Crucial for Eastward Propagation of Madden-Julian Oscillation
title_fullStr The Tibetan Plateau Uplift is Crucial for Eastward Propagation of Madden-Julian Oscillation
title_full_unstemmed The Tibetan Plateau Uplift is Crucial for Eastward Propagation of Madden-Julian Oscillation
title_short The Tibetan Plateau Uplift is Crucial for Eastward Propagation of Madden-Julian Oscillation
title_sort tibetan plateau uplift is crucial for eastward propagation of madden-julian oscillation
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6820537/
https://www.ncbi.nlm.nih.gov/pubmed/31664057
http://dx.doi.org/10.1038/s41598-019-51461-w
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