Atlantic climate variability and predictability: A CLIVAR perspective by Hurrell, J, Visbeck, M, Busalacchi, A, Clarke, R, Delworth, T, Dickson, R, Johns, W, Koltermann, K, Kushnir, Y, Marshall, D, Mauritzen, C, McCartney, MS, Piola, A, Reason, C, Reverdin, G, Schott, F, Sutton, R, Wainer, I, Wright, D