Rectified effects of tropical instability wave (TIW)-induced atmospheric wind feedback in the tropical Pacific

Recent high-resolution space-based observations reveal significant two-way air-sea interactions associated with tropical instability waves (TIWs) in the tropical oceans. But in most large-scale climate modeling studies, the atmospheric wind response to TIW-induced sea surface temperature (SST_TTW) anomalies has not been taken into account realistically and thus the corresponding feedbacks to the ocean are not known. Here we apply a singular value decomposition (SVD) analysis to satellite data to derive an empirical model for the SST_TTW induced wind stress (Τ_TIW) variability in the eastern tropical Pacific. The derived SST_TIW-Τ_TIW relationship is then nested into a basin-scale ocean and a hybrid coupled ocean-atmosphere model of the tropical Pacific to take into account the TIW-induced wind-SST coupling. It is demonstrated that TIW-induced wind feedback to the ocean can have a rectified effect on large-scale mean ocean state and interannual variability, with an asymmetric difference in SST (a cooling) and a significant modulation of ENSO amplitude.