Recent changes in the precipitation-driving processes over the southern tropical Andes/western Amazon
International audience Analyzing December-February (DJF) precipitation in the southern tropical Andes—STA (12 ∘ S -20 ∘ S > 3000 m.a.s.l) allows revisiting regional atmospheric circulation features accounting for its interannual variability over the past 35 years (1982-2018). In a region where in...
Published in: | Climate Dynamics |
---|---|
Main Authors: | , , , , , |
Other Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2020
|
Subjects: | |
Online Access: | https://insu.hal.science/insu-03706477 https://doi.org/10.1007/s00382-020-05132-6 |
id |
ftanrparis:oai:HAL:insu-03706477v1 |
---|---|
record_format |
openpolar |
spelling |
ftanrparis:oai:HAL:insu-03706477v1 2024-09-30T14:39:50+00:00 Recent changes in the precipitation-driving processes over the southern tropical Andes/western Amazon Segura, Hans Espinoza, Jhan Carlo Junquas, Clementine Lebel, Thierry Vuille, Mathias Garreaud, Rene Institut des Géosciences de l’Environnement (IGE) Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ) Université Grenoble Alpes (UGA) ANR-18-MPGA-0008,AMANECER,Connexion Amazone - Andes(2018) 2020 https://insu.hal.science/insu-03706477 https://doi.org/10.1007/s00382-020-05132-6 en eng HAL CCSD Springer Verlag info:eu-repo/semantics/altIdentifier/doi/10.1007/s00382-020-05132-6 insu-03706477 https://insu.hal.science/insu-03706477 BIBCODE: 2020ClDy.54.2613S doi:10.1007/s00382-020-05132-6 ISSN: 0930-7575 EISSN: 1432-0894 Climate Dynamics https://insu.hal.science/insu-03706477 Climate Dynamics, 2020, 54, pp.2613-2631. ⟨10.1007/s00382-020-05132-6⟩ Amazon-Andes connectivity Altiplano precipitation Amazon convection South America atmospheric circulation [SDU]Sciences of the Universe [physics] [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology info:eu-repo/semantics/article Journal articles 2020 ftanrparis https://doi.org/10.1007/s00382-020-05132-6 2024-09-05T00:06:58Z International audience Analyzing December-February (DJF) precipitation in the southern tropical Andes—STA (12 ∘ S -20 ∘ S > 3000 m.a.s.l) allows revisiting regional atmospheric circulation features accounting for its interannual variability over the past 35 years (1982-2018). In a region where in-situ rainfall stations are sparse, the CHIRPS precipitation product is used to identify the first mode of interannual DJF precipitation variability (PC1-Andes). A network of 98 rain-gauge stations further allows verifying that PC1-Andes properly represents the spatio-temporal rainfall distribution over the region; in particular a significant increase in DJF precipitation over the period of study is evident in both in-situ data and PC1-Andes. Using the ERA-Interim data set, we found that aside from the well-known relationship between precipitation and upper-level easterlies over the STA, PC1-Andes is also associated with upward motion over the western Amazon (WA), a link that has not been reported before. The ascent over the WA is a component of the meridional circulation between the tropical North Atlantic and western tropical South America—WTSA (80 ∘ W -60 ∘ W 35 ∘ S -10 ∘ N ). Indeed, the precipitation increase over the last 2 decades is concomitant with the strengthening of this meridional circulation. An intensified upward motion over the WA has moistened the mid-troposphere over WTSA, and as a consequence, a decreased atmospheric stability between the mid- and the upper troposphere is observed over this region, including the STA. We further show that, over the last 15 years or so, the year-to-year variability of STA precipitation (periodicity < 8 years) has been significantly associated with upward motion over the WA, while upper-level easterlies are no longer significantly correlated with precipitation. These observations suggests that the STA have experienced a transition from a dry to a wet state in association with a change in the dominant mode of atmospheric circulation. In the former dominant ... Article in Journal/Newspaper North Atlantic Portail HAL-ANR (Agence Nationale de la Recherche) Climate Dynamics 54 5-6 2613 2631 |
institution |
Open Polar |
collection |
Portail HAL-ANR (Agence Nationale de la Recherche) |
op_collection_id |
ftanrparis |
language |
English |
topic |
Amazon-Andes connectivity Altiplano precipitation Amazon convection South America atmospheric circulation [SDU]Sciences of the Universe [physics] [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology |
spellingShingle |
Amazon-Andes connectivity Altiplano precipitation Amazon convection South America atmospheric circulation [SDU]Sciences of the Universe [physics] [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology Segura, Hans Espinoza, Jhan Carlo Junquas, Clementine Lebel, Thierry Vuille, Mathias Garreaud, Rene Recent changes in the precipitation-driving processes over the southern tropical Andes/western Amazon |
topic_facet |
Amazon-Andes connectivity Altiplano precipitation Amazon convection South America atmospheric circulation [SDU]Sciences of the Universe [physics] [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology |
description |
International audience Analyzing December-February (DJF) precipitation in the southern tropical Andes—STA (12 ∘ S -20 ∘ S > 3000 m.a.s.l) allows revisiting regional atmospheric circulation features accounting for its interannual variability over the past 35 years (1982-2018). In a region where in-situ rainfall stations are sparse, the CHIRPS precipitation product is used to identify the first mode of interannual DJF precipitation variability (PC1-Andes). A network of 98 rain-gauge stations further allows verifying that PC1-Andes properly represents the spatio-temporal rainfall distribution over the region; in particular a significant increase in DJF precipitation over the period of study is evident in both in-situ data and PC1-Andes. Using the ERA-Interim data set, we found that aside from the well-known relationship between precipitation and upper-level easterlies over the STA, PC1-Andes is also associated with upward motion over the western Amazon (WA), a link that has not been reported before. The ascent over the WA is a component of the meridional circulation between the tropical North Atlantic and western tropical South America—WTSA (80 ∘ W -60 ∘ W 35 ∘ S -10 ∘ N ). Indeed, the precipitation increase over the last 2 decades is concomitant with the strengthening of this meridional circulation. An intensified upward motion over the WA has moistened the mid-troposphere over WTSA, and as a consequence, a decreased atmospheric stability between the mid- and the upper troposphere is observed over this region, including the STA. We further show that, over the last 15 years or so, the year-to-year variability of STA precipitation (periodicity < 8 years) has been significantly associated with upward motion over the WA, while upper-level easterlies are no longer significantly correlated with precipitation. These observations suggests that the STA have experienced a transition from a dry to a wet state in association with a change in the dominant mode of atmospheric circulation. In the former dominant ... |
author2 |
Institut des Géosciences de l’Environnement (IGE) Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ) Université Grenoble Alpes (UGA) ANR-18-MPGA-0008,AMANECER,Connexion Amazone - Andes(2018) |
format |
Article in Journal/Newspaper |
author |
Segura, Hans Espinoza, Jhan Carlo Junquas, Clementine Lebel, Thierry Vuille, Mathias Garreaud, Rene |
author_facet |
Segura, Hans Espinoza, Jhan Carlo Junquas, Clementine Lebel, Thierry Vuille, Mathias Garreaud, Rene |
author_sort |
Segura, Hans |
title |
Recent changes in the precipitation-driving processes over the southern tropical Andes/western Amazon |
title_short |
Recent changes in the precipitation-driving processes over the southern tropical Andes/western Amazon |
title_full |
Recent changes in the precipitation-driving processes over the southern tropical Andes/western Amazon |
title_fullStr |
Recent changes in the precipitation-driving processes over the southern tropical Andes/western Amazon |
title_full_unstemmed |
Recent changes in the precipitation-driving processes over the southern tropical Andes/western Amazon |
title_sort |
recent changes in the precipitation-driving processes over the southern tropical andes/western amazon |
publisher |
HAL CCSD |
publishDate |
2020 |
url |
https://insu.hal.science/insu-03706477 https://doi.org/10.1007/s00382-020-05132-6 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
ISSN: 0930-7575 EISSN: 1432-0894 Climate Dynamics https://insu.hal.science/insu-03706477 Climate Dynamics, 2020, 54, pp.2613-2631. ⟨10.1007/s00382-020-05132-6⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1007/s00382-020-05132-6 insu-03706477 https://insu.hal.science/insu-03706477 BIBCODE: 2020ClDy.54.2613S doi:10.1007/s00382-020-05132-6 |
op_doi |
https://doi.org/10.1007/s00382-020-05132-6 |
container_title |
Climate Dynamics |
container_volume |
54 |
container_issue |
5-6 |
container_start_page |
2613 |
op_container_end_page |
2631 |
_version_ |
1811642424004444160 |