The hammam effect or how a warm ocean enhances large scale atmospheric predictability

The atmosphere’s chaotic nature limits its short-term predictability. Furthermore, there is little knowledge on how the difficulty of forecasting weather may be affected by anthropogenic climate change. Here, we address this question by employing metrics issued from dynamical systems theory to descr...

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Detalles Bibliográficos
Autores: Faranda, Davide, Álvarez Castro, María del Carmen, Messori, Gabriele, Rodrigues, David, Yiou, Pascal
Tipo de recurso: artículo
Fecha de publicación:2019
País:España
Institución:Universidad Pablo de Olavide (UPO)
Repositorio:RIO. Repositorio Institucional Olavide
Idioma:inglés
OAI Identifier:oai:rio.upo.es:10433/22865
Acceso en línea:https://hdl.handle.net/10433/22865
Access Level:acceso abierto
Palabra clave:Hammam effect
Climate dynamics
Dynamical systems
Predictability
Descripción
Sumario:The atmosphere’s chaotic nature limits its short-term predictability. Furthermore, there is little knowledge on how the difficulty of forecasting weather may be affected by anthropogenic climate change. Here, we address this question by employing metrics issued from dynamical systems theory to describe the atmospheric circulation and infer the dynamical properties of the climate system. Specifically, we evaluate the changes in the sub-seasonal predictability of the large-scale atmospheric circulation over the North Atlantic for the historical period and under anthropogenic forcing, using centennial reanalyses and CMIP5 simulations. For the future period, most datasets point to an increase in the atmosphere’s predictability. AMIP simulations with 4K warmer oceans and 4 × atmospheric CO2 concentrations highlight the prominent role of a warmer ocean in driving this increase. We term this the hammam effect. Such effect is linked to enhanced zonal atmospheric patterns, which are more predictable than meridional configurations.