Liu, Z., 1993: Notes and Correspondence: Interannual positive feedbacks in a simple extratropical air-sea coupling system. Journal of the Atmospheric Sciences, 50(17), 3022-3028.

Abstract: A simple theoretical analysis identified three possible feedbacks in the extratropics; the upwelling mode, the SST-Sverdrup mode, and the SST-evaporation mode. The upwelling mode becomes unstable when the atmosphere responses to a warm SST anomaly predominantly with a high surface pressure. In contrast, the SST-Sverdrup mode is destabilized when the atmosphere responses to a warm SST with a low pressure. In the region of mean westerly wind, the SST-evaporation mode is unstable when the atmospheric response to a warm SST is a quarter-wavelength to the south. The upwelling mode seems to favor low-latitude regions, while the two SST modes seem to favor mid-high latitudes. It is suggested that the relative position of the stationary atmospheric response to anomalous SST is of crucial importance for the extratropical ocean-atmosphere interaction.