Fast response of the Atlantic meridional overturning circulation to mid-latitude winds

Frajka-Williams, E. and Landerer, F. and Lee, T.


abstract: In situ observations of transbasin deep ocean transports at 26^\circN show variability on monthly to decadal timescales (2004–2015). Satellite-based estimates of ocean bottom pressure from the Gravity Recovery and Climate Experiment (GRACE) satellites were previously used to estimate interannual variability of deep ocean transports at 26^\circN. Here, we use GRACE ocean bottom pressure, reanalysis winds and \textitin situ transport estimates at 26^\circN to diagnose the large-scale response of the deep ocean circulation to wind-forcing. We find that deep ocean transports—including those associated with a reversal of the Atlantic meridional overturning circulation in 2009/10 and 2010/11—are part of a large-scale response to wind stress curl over the intergyre-gyre region. Wind-forcing dominates deep ocean circulation variability on monthly timescales, but interannual fluctuations in the residual \textitin situ transports (after removing the wind-effect) are also captured by GRACE bottom pressure measurements. On decadal timescales, uncertainty in regional trends in GRACE ocean bottom pressure preclude investigation of decadal-timescale transport trends.

@article{FrajkaWilliams-etal-2018b,
  author = {Frajka-Williams, E. and Landerer, F. and Lee, T.},
  year = {submitted},
  title = {Fast response of the Atlantic meridional overturning circulation to mid-latitude winds},
  journal = {Geophys. Res. Lett.}
}