Frontiers in Earth Science (Feb 2023)
Influence of the North American dipole on the Atlantic warm pool
Abstract
Using the observational data, the Coupled Model Intercomparison Project phase 6 (CMIP6) models and the numerical experiment, this study examines the influence of the North American dipole (NAD) on the Atlantic warm pool (AWP). The results show that a strong positive (negative) phase of the winter NAD tends to inhibit (favor) the development of AWP in its area and depth in subsequent months. As opposed to the North Atlantic Oscillation (NAO), the NAD plays a more pivotal role in influencing the AWP due to its effectiveness in forcing the tropical North Atlantic (TNA) SST variability, which means that AWP variability may be more of a lagging response to NAD atmospheric forcing than a lagging response to NAO atmospheric forcing. Additional analysis indicates that the winter NAD-like atmospheric signal may be stored in the following AWP, thus markedly influencing the TNA precipitation and air temperature in summer. It is speculated that the AWP may act as a bridge linking winter NAD to the following summer precipitation and air temperature in the TNA region.
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