1 Erratum to: Clim Dyn DOI 10.1007/s00382-007-0349-3

Because of misunderstanding between authors of the paper and some data providers, we are responsible for some omission in the authors list and acknowledgements.

So we want to give here a new author list:

A. Nicault, S. Alleaume, S. Brewer, M. Carrer, P. Nola, E. Guttierez, J.L. Edouard, C. Urbinati and J. Guiot

And we want also acknowledge the consortium FORMAT (project ENV4-CT97-0641 funded by EU) for a big part of the data provided for this study.