Interaction between decadal-to-multidecadal oceanic variability and sudden stratospheric warmings

Major sudden stratospheric warmings (SSWs) are the most important phenomena of the wintertime boreal stratospheric variability.During SSWs, the polar temperature increases abruptly, and easterlies prevail in the stratosphere. Their effects extend farther from the polar stratosphere, affecting near-s...

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Detalles Bibliográficos
Autores: Ayargüena Porras, Blanca, Manzini, Elisa, Calvo Fernández, Natalia, Matei, Daniela
Tipo de recurso: artículo
Fecha de publicación:2021
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/4419
Acceso en línea:https://hdl.handle.net/20.500.14352/4419
Access Level:acceso abierto
Palabra clave:52
Sea-ice loss
Atmospheric response
Arctic amplification
CMIP5 simulations
Atlantic
Frequency
Climatology
Oscillation
Modulaton
Mechanisms
Física atmosférica
2501 Ciencias de la Atmósfera
Descripción
Sumario:Major sudden stratospheric warmings (SSWs) are the most important phenomena of the wintertime boreal stratospheric variability.During SSWs, the polar temperature increases abruptly, and easterlies prevail in the stratosphere. Their effects extend farther from the polar stratosphere, affecting near-surface circulation. According to observations, SSWs are not equally distributed in time, with decades experiencing very few events, while others experiencing SSWs almost every winter. Some sources of this SSW multidecadal variability can be traced back to sea surface temperature changes.Here, we investigate the effects of Pacific decadal variability (PDV) and Atlanticmultidecadal variability (AMV) on SSWs. We use for the first time a large ensemble of historical experiments to examine the modulation of the frequency, tropospheric precursors, and impact of SSWs by the PDV and AMV.We find a strong impact of the PDV on the occurrence of SSWs, with a higher SSW frequency for the positive phase of the PDV. This PDV influence ismediated by constructive interference of PDV anomalies with tropospheric stationary waves. The main effect of AMV is, instead, a modulation of the tropospheric response to SSWs, a finding that can be useful for predicting the tropospheric fingerprint of SSWs.