High and low NAO Gulf Stream transport: Annual mean Gulf Stream transport estimates across cross-sections at each latitude from 27¡N to 35¡N (bottom panel) and at each longitude from 75¡W to 50¡W (top panel). The point of separation is shown by black solid line. The high (low) NAO transport estimates are shown with dark bars and associated errors are depicted with blue (red) lines. Observations are shown as black dots and obtained from estimates made by Leaman et al., (1987), Leaman et al., (1989), Halkin and Rossby, (1985), Johns et al., (1995) and Hogg (1992) at 27¡N, 29¡N, 73¡W, 68¡W, 60¡W, and 55¡W respectively. Model results are seen to underestimate the data values.