IGF



Publikacja

Upper ocean response to the passage of two sequential typhoons

Baranowski, D.B. , Flatau, P.J., Chen, S., Black, P.G.

Ocean Science

10, 2014, 559– 570, 10.5194/os-10-559-2014

The atmospheric wind stress forcing and the oceanic response are examined for the period between 15 September 2008 and 6 October 2008, during which two typhoons – Hagupit and Jangmi – passed through the same region of the western Pacific at Saffir–Simpson intensity categories one and three, respectively. A three-dimensional oceanic mixed layer model is compared against the remote
sensing observations as well as high-repetition Argo float data. Numerical model simulations suggested that magnitude of the cooling caused by the second typhoon, Jangmi, would have been significantly larger if the ocean had not already been influenced by the first typhoon, Hagupit. It is es-
timated that the temperature anomaly behind Jangmi would have been about 0.4◦C larger in both cold wake and left side of the track. The numerical simulations suggest that the magnitude and position of Jangmi’s cold wake depends on the precursor state of the ocean as well as lag between ty-
phoons. Based on sensitivity experiments we show that temperature anomaly difference between “single typhoon” and “two typhoons” as well as magnitude of the cooling strongly depends on the distance between them. The amount of kinetic energy and coupling with inertial oscillations are im-
portant factors for determining magnitude of the temperature anomaly behind moving typhoons. This paper indicates that studies of ocean–atmosphere tropical cyclone interaction will benefit from denser, high-repetition Argo float measurements.


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