Observation of Topographic Rossby Waves Triggered by Kuroshio Path Meander in the East China Sea

Abstract

Topographic Rossby waves (TRWs) are transverse waves induced by disturbance under the conservation of potential vorticity (Rhines, 1970) and strongly contribute to variabilities in deep ocean dynamics (Hamilton, 2009). In fact, previous studies have determined that the deep current variabilities of the Continental Rise located north of the Gulf Stream are dominated by TRWs (Hogg, 1981;Thompson, 1971Thompson, , 1977 with periods of 20-100 days, which conforms to the dispersion relation of TRWs described by Rhines (1970). Moreover, as a branch of the Gulf Stream system, the pulsations of the Gulf Stream's Loop Current may serve as the energy source of TRWs (Hamilton, 1990;Oey, 1996;Oey & Lee, 2002) in the Gulf of Mexico. Meanwhile, Oey (2008) elucidated the generation mechanism of short-period TRWs excited by the Loop Current using a high-resolution model. These results were later supported by the observations made by Hamilton (2009). Thus, TRWs play a crucial role in energy transmission by gaining energy from upper-layer eddies through potential vorticity adjustments during the shedding and translation of eddies from the Loop Current.