An Atmospheric Bridge Between the Subpolar and Tropical Atlantic Regions: A Perplexing Asymmetric Teleconnection

The largest sea surface temperature (SST) anomalies associated with Atlantic Multidecadal Variability (AMV) occur over the subpolar gyre, yet it is tropical from where global impacts of AMV originate. Processes that communicate SST change gyre to North thus comprise a crucial mechanism AMV. Here we use idealized model experiments show such communication accomplished by an “atmospheric bridge.” Our results demonstrate unexpected asymmetry: atmosphere effective in communicating cold SSTs north Atlantic, via immediate extratropical atmospheric circulation invokes slower wind-driven evaporative cooling along Eastern Basin and into tropics. Warm do not elicit robust response. highlight key dynamical feature for which warm phases are opposites.