Observed three-dimensional structure of ocean cooling induced by Pacific tropical cyclones

Sea surface cooling along tropical cyclone (TC) tracks has been well observed, but a complete understanding of the full three-dimensional structure of upper ocean TC-induced cooling is still needed. In this study, observed ocean temperature profiles derived from Argo floats and TC statistics from 1996 to 2012 are used to determine the three-dimensional structure of TC-induced cooling over the northwest Pacific. The average TC-induced sea surface temperature change derived from Argo reaches -1.4 degrees C, which agrees well with satellite-derived estimates. The Argo profiles further reveal that this cooling can extend to a depth of similar to 30m and can persist for about 20days. The time scale of cooling recovery is somewhat longer in subsurface layers between a depth of similar to 10-15m. Over the ocean domain where the mixed layer is shallower (deeper), the cooling is stronger (weaker), shallower (deeper), and more (less) persistent. The effect of initial MLD on the cooling derived from Argo observations may be only half of the idealized piecewise continuous model of tropical cyclone. These findings have implications for the total upper ocean heat content change induced by northwest Pacific TCs.