海洋科学
海洋科學
해양과학
MARINE SCIENCES
2013年
2期
112-117
,共6页
开尔文波%罗斯贝波%西边界反射%海面高度异常%负位相%印度洋偶极子(IOD)
開爾文波%囉斯貝波%西邊界反射%海麵高度異常%負位相%印度洋偶極子(IOD)
개이문파%라사패파%서변계반사%해면고도이상%부위상%인도양우겁자(IOD)
Kelvin wave%Rossby wave%western boundary reflection%sea level anomalies%negative%the Indian Ocean Dipole (IOD)
使用美国海洋环境预报中心(NCEP)逐日的表面风场和热通量强迫的大洋环流模式(LICOM)研究了1998~1999年负位相印度洋偶极子(IOD)事件期间赤道印度洋环流长波动力机制的年际变化.模式能够很好地模拟出高度计资料的海面高度异常.使用垂直模分解方法对模式输出进行赤道波分解,结果表明:西边界反射在负位相IOD事件发生、发展和衰亡过程中起了重要作用.虽然西边界反射在正、负位相IOD期间均起到了重要的负反馈作用,但两者的来源机制却是不同的.在1998~1999年负位相IOD 事件期间,西边界处产生的两个上翻的开尔文波均来自赤道罗斯贝波在西边界处的反射.第一个上翻的开尔文波主要在西印度洋和中印度洋发生作用,由于受到西风异常强迫的下沉的开尔文波的影响,它并没有成功到达东印度洋,但是却一定程度上削弱了中东印度洋的下沉异常;而第二个上翻开尔文波成功到达东爪哇沿岸终止了那里的下沉异常,最终终止了负位相IOD事件.首次从赤道长波动力学角度解释了1998~1999年负位相IOD事件的结束机制,有利于进一步了解IOD对印度洋周边气候甚至太平洋的影响.
使用美國海洋環境預報中心(NCEP)逐日的錶麵風場和熱通量彊迫的大洋環流模式(LICOM)研究瞭1998~1999年負位相印度洋偶極子(IOD)事件期間赤道印度洋環流長波動力機製的年際變化.模式能夠很好地模擬齣高度計資料的海麵高度異常.使用垂直模分解方法對模式輸齣進行赤道波分解,結果錶明:西邊界反射在負位相IOD事件髮生、髮展和衰亡過程中起瞭重要作用.雖然西邊界反射在正、負位相IOD期間均起到瞭重要的負反饋作用,但兩者的來源機製卻是不同的.在1998~1999年負位相IOD 事件期間,西邊界處產生的兩箇上翻的開爾文波均來自赤道囉斯貝波在西邊界處的反射.第一箇上翻的開爾文波主要在西印度洋和中印度洋髮生作用,由于受到西風異常彊迫的下沉的開爾文波的影響,它併沒有成功到達東印度洋,但是卻一定程度上削弱瞭中東印度洋的下沉異常;而第二箇上翻開爾文波成功到達東爪哇沿岸終止瞭那裏的下沉異常,最終終止瞭負位相IOD事件.首次從赤道長波動力學角度解釋瞭1998~1999年負位相IOD事件的結束機製,有利于進一步瞭解IOD對印度洋週邊氣候甚至太平洋的影響.
사용미국해양배경예보중심(NCEP)축일적표면풍장화열통량강박적대양배류모식(LICOM)연구료1998~1999년부위상인도양우겁자(IOD)사건기간적도인도양배류장파동력궤제적년제변화.모식능구흔호지모의출고도계자료적해면고도이상.사용수직모분해방법대모식수출진행적도파분해,결과표명:서변계반사재부위상IOD사건발생、발전화쇠망과정중기료중요작용.수연서변계반사재정、부위상IOD기간균기도료중요적부반궤작용,단량자적래원궤제각시불동적.재1998~1999년부위상IOD 사건기간,서변계처산생적량개상번적개이문파균래자적도라사패파재서변계처적반사.제일개상번적개이문파주요재서인도양화중인도양발생작용,유우수도서풍이상강박적하침적개이문파적영향,타병몰유성공도체동인도양,단시각일정정도상삭약료중동인도양적하침이상;이제이개상번개이문파성공도체동조왜연안종지료나리적하침이상,최종종지료부위상IOD사건.수차종적도장파동역학각도해석료1998~1999년부위상IOD사건적결속궤제,유리우진일보료해IOD대인도양주변기후심지태평양적영향.
The interannual variation of long wave dynamics of the negative Indian Ocean Dipole (IOD) event of 1998—1999 are studied using Ocean General Circulation Model (LICOM) forced by daily surface winds and heat flux of National Centers for Environmental Prediction (NCEP), the simulation can reproduce the sea level anoma-lies of the altimetry data observations well. The equatorial Kelvin wave and Rossby wave decomposed from model output using vertical mode decomposition method show that western boundary reflection plays an important role in the evolution of negative IOD. Different from positive IOD events, the role of off-equatorial Rossby wave can be neglected and both two upwelling Kelvin waves are reflected from equatorial Rossby waves at the western bound-ary during negative IOD events. During 1998—1999 negative IOD events, the first upwelling Kelvin wave func-tions in the western and central Indian Ocean and was overwhelmed by westerlies anomalies forced downwelling Kelvin wave;and the second upwelling Kelvin wave terminates the downwelling anomalies off the Java coast and terminates the 1998—1999 negative IOD event eventually. The paper explains the termination mechanism of nega-tive IOD events during 1998—1999 from the view of equatorial long wave dynamics at the first time, which laid down the foundation of understanding the influence of IOD on the surrounding climate even the Pacific Ocean.