Evidence for a modulation of the intraseasonal summer temperature in Eastern Patagonia by the Madden-Julian Oscillation

We describe the relationship between the intraseasonal component of surface air temperature (SAT) variability in Eastern Patagonia and the Madden-Julian Oscillation (MJO) during austral summer based on ~50 years of daily instrumental records, the Twentieth Century Reanalysis, and a century-long MJO...

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Autores principales: Vera, Carolina Susana, Cerne, Silvia Bibiana
Publicado: 2015
Materias:
air temperature
air-sea interaction
atmospheric convection
extratropical environment
longwave radiation
Madden-Julian oscillation
seasonal variation
summer
temperature profile
Atlantic Ocean
Atlantic Ocean (Southwest)
Pacific Ocean
Pacific Ocean (South)
Patagonia
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01480227_v120_n15_p7340_JacquesCoper
http://hdl.handle.net/20.500.12110/paper_01480227_v120_n15_p7340_JacquesCoper
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_01480227_v120_n15_p7340_JacquesCoper
record_format dspace
spelling paper:paper_01480227_v120_n15_p7340_JacquesCoper2023-06-08T15:13:08Z Evidence for a modulation of the intraseasonal summer temperature in Eastern Patagonia by the Madden-Julian Oscillation Vera, Carolina Susana Cerne, Silvia Bibiana air temperature air-sea interaction atmospheric convection extratropical environment longwave radiation Madden-Julian oscillation seasonal variation summer temperature profile Atlantic Ocean Atlantic Ocean (Southwest) Pacific Ocean Pacific Ocean (South) Patagonia We describe the relationship between the intraseasonal component of surface air temperature (SAT) variability in Eastern Patagonia and the Madden-Julian Oscillation (MJO) during austral summer based on ~50 years of daily instrumental records, the Twentieth Century Reanalysis, and a century-long MJO index reconstruction. Our results show that the summer SAT variability in Patagonia is highly driven by the intraseasonal activity (~80%), especially by that associated with the MJO. The active MJO phases modulate the spatial mean intraseasonal temperature signal in Eastern Patagonia with ~1.5°C of amplitude. In most of the region, the warmest (coldest) conditions are found during active phase 8 (4). These opposite states of the temperature perturbations are related to almost inverse midlevel circulation anomalies over southern South America and the southwest Atlantic, which are part of a large-scale Rossby-like wave train of alternating circulation anomalies extended along the South Pacific. The corresponding outgoing longwave radiation anomalies suggest that these structuresmay be triggered by anomalous convection in the tropics. Furthermore, we show that intraseasonal heat waves in southeastern Patagonia tend to occur during active MJO phase 8. These events are also induced by a wave train pattern over the South Pacific, associated with other intraseasonal variability sources. Hence, as shown in a case study, circulation anomalies over the South Pacific triggered, in general, by tropical convection variability and, in particular, by theMJO activitymay constructively interact with circulation patterns resulting fromthe extratropical dynamics, eventually leading to intraseasonal heat waves in southeastern Patagonia. © 2015. American Geophysical Union. All Rights Reserved. Fil:Vera, C.S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Cerne, S.B. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2015 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01480227_v120_n15_p7340_JacquesCoper http://hdl.handle.net/20.500.12110/paper_01480227_v120_n15_p7340_JacquesCoper
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic air temperature
air-sea interaction
atmospheric convection
extratropical environment
longwave radiation
Madden-Julian oscillation
seasonal variation
summer
temperature profile
Atlantic Ocean
Atlantic Ocean (Southwest)
Pacific Ocean
Pacific Ocean (South)
Patagonia
spellingShingle air temperature
air-sea interaction
atmospheric convection
extratropical environment
longwave radiation
Madden-Julian oscillation
seasonal variation
summer
temperature profile
Atlantic Ocean
Atlantic Ocean (Southwest)
Pacific Ocean
Pacific Ocean (South)
Patagonia
Vera, Carolina Susana
Cerne, Silvia Bibiana
Evidence for a modulation of the intraseasonal summer temperature in Eastern Patagonia by the Madden-Julian Oscillation
topic_facet air temperature
air-sea interaction
atmospheric convection
extratropical environment
longwave radiation
Madden-Julian oscillation
seasonal variation
summer
temperature profile
Atlantic Ocean
Atlantic Ocean (Southwest)
Pacific Ocean
Pacific Ocean (South)
Patagonia
description We describe the relationship between the intraseasonal component of surface air temperature (SAT) variability in Eastern Patagonia and the Madden-Julian Oscillation (MJO) during austral summer based on ~50 years of daily instrumental records, the Twentieth Century Reanalysis, and a century-long MJO index reconstruction. Our results show that the summer SAT variability in Patagonia is highly driven by the intraseasonal activity (~80%), especially by that associated with the MJO. The active MJO phases modulate the spatial mean intraseasonal temperature signal in Eastern Patagonia with ~1.5°C of amplitude. In most of the region, the warmest (coldest) conditions are found during active phase 8 (4). These opposite states of the temperature perturbations are related to almost inverse midlevel circulation anomalies over southern South America and the southwest Atlantic, which are part of a large-scale Rossby-like wave train of alternating circulation anomalies extended along the South Pacific. The corresponding outgoing longwave radiation anomalies suggest that these structuresmay be triggered by anomalous convection in the tropics. Furthermore, we show that intraseasonal heat waves in southeastern Patagonia tend to occur during active MJO phase 8. These events are also induced by a wave train pattern over the South Pacific, associated with other intraseasonal variability sources. Hence, as shown in a case study, circulation anomalies over the South Pacific triggered, in general, by tropical convection variability and, in particular, by theMJO activitymay constructively interact with circulation patterns resulting fromthe extratropical dynamics, eventually leading to intraseasonal heat waves in southeastern Patagonia. © 2015. American Geophysical Union. All Rights Reserved.
author Vera, Carolina Susana
Cerne, Silvia Bibiana
author_facet Vera, Carolina Susana
Cerne, Silvia Bibiana
author_sort Vera, Carolina Susana
title Evidence for a modulation of the intraseasonal summer temperature in Eastern Patagonia by the Madden-Julian Oscillation
title_short Evidence for a modulation of the intraseasonal summer temperature in Eastern Patagonia by the Madden-Julian Oscillation
title_full Evidence for a modulation of the intraseasonal summer temperature in Eastern Patagonia by the Madden-Julian Oscillation
title_fullStr Evidence for a modulation of the intraseasonal summer temperature in Eastern Patagonia by the Madden-Julian Oscillation
title_full_unstemmed Evidence for a modulation of the intraseasonal summer temperature in Eastern Patagonia by the Madden-Julian Oscillation
title_sort evidence for a modulation of the intraseasonal summer temperature in eastern patagonia by the madden-julian oscillation
publishDate 2015
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01480227_v120_n15_p7340_JacquesCoper
http://hdl.handle.net/20.500.12110/paper_01480227_v120_n15_p7340_JacquesCoper
work_keys_str_mv AT veracarolinasusana evidenceforamodulationoftheintraseasonalsummertemperatureineasternpatagoniabythemaddenjulianoscillation
AT cernesilviabibiana evidenceforamodulationoftheintraseasonalsummertemperatureineasternpatagoniabythemaddenjulianoscillation
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