Internal and external variability in regional simulations of the Iberian Peninsula climate over the last millennium

In this study we analyse the role of internal variability in regional climate simulations through a comparison of two regional paleoclimate simulations for the last millennium. They share the same external forcings and model configuration, differing only in the initial condition used to run the driv...

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Detalles Bibliográficos
Autores: Gómez-Navarro, J. J., Montávez, J. P., Jiménez-Guerrero, P., Jerez, S., Lorente-Plazas, R., González-Rouco, J. F., Zorita, Eduardo
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2011
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/62232
Acceso en línea:http://hdl.handle.net/10261/62232
Access Level:acceso abierto
Palabra clave:Paleoclimatología
Paleoclimatology
Iberian Peninsula
Península Ibérica
ddc:551
Descripción
Sumario:In this study we analyse the role of internal variability in regional climate simulations through a comparison of two regional paleoclimate simulations for the last millennium. They share the same external forcings and model configuration, differing only in the initial condition used to run the driving global model simulation. A comparison of these simulations allows us to study the role of internal variability in climate models at regional scales, and how it affects the long-term evolution of climate variables such as temperature and precipitation. The results indicate that, although temperature is homogeneously sensitive to the effect of external forcings, the evolution of precipitation is more strongly governed by random and unpredictable internal dynamics. There are, however, some areas where the role of internal variability is lower than expected, allowing precipitation to respond to the external forcings, and we explore the underlying physical mechanisms responsible. We find that special attention should be paid when comparing the evolution of simulated precipitation with proxy reconstructions at regional scales. In particular, this study identifies areas, depending on the season, in which this comparison would be meaningful, but also other areas where good agreement between model simulations and reconstructions should not be expected even if both are perfect.