The Role of the Stratosphere in Subseasonal to Seasonal Prediction: 2. Predictability Arising From Stratosphere‐Troposphere Coupling
Détails
ID Serval
serval:BIB_81C459BB1700
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
The Role of the Stratosphere in Subseasonal to Seasonal Prediction: 2. Predictability Arising From Stratosphere‐Troposphere Coupling
Périodique
Journal of Geophysical Research: Atmospheres
ISSN
2169-897X
2169-8996
2169-8996
Statut éditorial
Publié
Date de publication
27/01/2020
Peer-reviewed
Oui
Volume
125
Numéro
2
Langue
anglais
Résumé
The stratosphere can have a significant impact on winter surface weather on subseasonal to seasonal (S2S) timescales. This study evaluates the ability of current operational S2S prediction systems to capture two important links between the stratosphere and troposphere: (1) changes in probabilistic prediction skill in the extratropical stratosphere by precursors in the tropics and the extratropical troposphere and (2) changes in surface predictability in the extratropics after stratospheric weak and strong vortex events. Probabilistic skill exists for stratospheric events when including extratropical tropospheric precursors over the North Pacific and Eurasia, though only a limited set of models captures the Eurasian precursors. Tropical teleconnections such as the Madden-Julian Oscillation, the Quasi-Biennial Oscillation, and El Niño–Southern Oscillation increase the probabilistic skill of the polar vortex strength, though these are only captured by a limited set of models. At the surface, predictability is increased over the United States, Russia, and the Middle East for weak vortex events, but not for Europe, and the change in predictability is smaller for strong vortex events for all prediction systems. Prediction systems with poorly resolved stratospheric processes represent this skill to a lesser degree. Altogether, the analyses indicate that correctly simulating stratospheric variability and stratosphere-troposphere dynamical coupling are critical elements for skillful S2S wintertime predictions.
Mots-clé
stratosphere, sub-seasonal predictability, S2S database, sudden stratospheric warming, stratosphere - troposphere coupling, North Atlantic Oscillation
Web of science
Site de l'éditeur
Open Access
Oui
Financement(s)
Fonds national suisse / PP00P2_170523
Création de la notice
08/03/2022 15:13
Dernière modification de la notice
11/07/2024 10:51