Based on mooring observations from Aug.1,2016 to Dec.14,2017,the characteristics and underlying mechanisms of near-inertial waves(NIWs)observed east of the Philippines were studied.Three strong NIW events were investi...Based on mooring observations from Aug.1,2016 to Dec.14,2017,the characteristics and underlying mechanisms of near-inertial waves(NIWs)observed east of the Philippines were studied.Three strong NIW events were investigated in detail.The NIWs in EventⅠwere induced by typhoon Lan and had the strongest magnitudes of 0.35 m/s.The maximum near-inertial kinetic energy(NIKE)was shown at the ocean surface.The NIW in EventⅡwas stimulated by a moderate cyclonic wind with the extreme NIKE located at about 110-m depth.The existence of a cyclonic eddy during EventsⅠandⅡled to a blue shift of near-inertial frequencies.For EventⅢ,the surface near-inertial signals were also induced by local weak wind,whereas the real generation mechanisms for the subsurface NIWs remain unclear.In particular,during EventⅢ,there was a nonlinear wave-wave interaction between NIWs and semidiurnal(D)tides,which further induced strong D±f waves.Overall,the NIWs in the three events exhibited distinct vertical structures.The NIWs in EventsⅠandⅡwere dominated by lower mode s with elevated NIKE well confined to the upper 250 m and 270 m,respectively.In contrast,the NIW EventⅢwas dominated by higher modes and the NIWs penetrated downward beyond 360 m.Such deep penetration of NIWs could be attributed to the weak wind stress curl and positive sea level anomalies associated with an anticyclonic eddy.In addition,the three NIW events had e-folding timescales of less than 7 days.展开更多
基金Supported by the National Key Research and Development Program of China(No.2020YFA0608801)the Scientific Instrument Developing Project of the Chinese Academy of Sciences(No.YJKYYQ20190047)+2 种基金the National Key Research and Development Program of China(Nos.2016YFC0301203,2017YFA0603202)the National Natural Science Foundation of China(No.42122041)The TS Scholar ProgramMooring and CTD data were collected onboard of R/V Kexue implementing the open research cruise NORC2021-09 supported by the NSFC Shiptime Sharing Project(No.42049909)。
文摘Based on mooring observations from Aug.1,2016 to Dec.14,2017,the characteristics and underlying mechanisms of near-inertial waves(NIWs)observed east of the Philippines were studied.Three strong NIW events were investigated in detail.The NIWs in EventⅠwere induced by typhoon Lan and had the strongest magnitudes of 0.35 m/s.The maximum near-inertial kinetic energy(NIKE)was shown at the ocean surface.The NIW in EventⅡwas stimulated by a moderate cyclonic wind with the extreme NIKE located at about 110-m depth.The existence of a cyclonic eddy during EventsⅠandⅡled to a blue shift of near-inertial frequencies.For EventⅢ,the surface near-inertial signals were also induced by local weak wind,whereas the real generation mechanisms for the subsurface NIWs remain unclear.In particular,during EventⅢ,there was a nonlinear wave-wave interaction between NIWs and semidiurnal(D)tides,which further induced strong D±f waves.Overall,the NIWs in the three events exhibited distinct vertical structures.The NIWs in EventsⅠandⅡwere dominated by lower mode s with elevated NIKE well confined to the upper 250 m and 270 m,respectively.In contrast,the NIW EventⅢwas dominated by higher modes and the NIWs penetrated downward beyond 360 m.Such deep penetration of NIWs could be attributed to the weak wind stress curl and positive sea level anomalies associated with an anticyclonic eddy.In addition,the three NIW events had e-folding timescales of less than 7 days.
