摘要
本文基于表层漂流浮标、卫星高度计等观测资料对全球亚中尺度非地转运动的季节变化及其影响开展了分析,发现亚中尺度非地转运动多发生在地转运动较活跃的海区,如湾流区、黑潮延伸体区和南极绕极流区等。同时,全球亚中尺度非地转运动普遍具有冬春强、夏秋弱的季节变化特征,但不同区域亚中尺度非地转运动的季节变化具有不同的调控机制,其中,在湾流区和黑潮延伸体区亚中尺度非地转运动的季节变化主要受混合层不稳定的调控,南极绕极流区亚中尺度非地转运动的季节变化受到混合层不稳定和锋生过程的共同调控。而亚中尺度非地转运动的季节变化可能对地转能量串级具有一定影响,在冬春季节,活跃的亚中尺度非地转运动可能会减弱地转能量的逆向串级,使地转运动平均波数增加。
In quasi-geostrophic theory which ignores the influence of ageostrophic motions,ocean energy is transferred to lower wavenumber and this cannot explain the ocean energy balance.Although the submesoscale ageostrophic motions have small magnitudes compared with the geostrophic motions on the whole,the submesoscale ageostrophic motions still occupy a non-negligible proportion in the upper ocean.Based on surface buoy drifter and altimeter data,this paper analyzes the seasonal variation and the impact of global submesoscale ageostrophic motions.The results revealed that submesoscale ageostrophic motions mostly occur in areas where geostrophic motions are active,such as the Gulf Stream region,the Kuroshio Extension region and the Antarctic Circumpolar Current region.At the same time,the submesoscale ageostrophic motions present distinct seasonal variation,that are commonly stronger in winter and spring,and weaker in summer and autumn.However,different modulation mechanisms are found in different regions.In the Gulf Stream and the Kuroshio Extension regions,the seasonal variation of submesoscale ageostrophic motions is mainly modulated by the mixed layer instability while in the Antarctic Circumpolar region,it is modulated by the combined effect of mixed layer instability and frontogenesis.The seasonal variation of submesoscale ageostrophic motions may affect the geostrophic energy cascade.In winter and spring,active submesoscale ageostrophic motions may weaken the reverse cascade of geostrophic energy,and the average wave number of geostrophic motions will increase.
作者
王芮芮
孙忠斌
Wang Ruirui;Sun Zhongbin(College of Oceanic and Atmospheric Science,Ocean University of China,Qingdao 266100,China;The Key Laboratory of Physical Oceanography,Ministry of Education,Ocean University of China,Qingdao 266100,China;Institute for Advanced Ocean Study, Ocean University of China, Qingdao 266100, China)
出处
《中国海洋大学学报（自然科学版）》
CAS
CSCD
北大核心
2022年第7期14-21,共8页
Periodical of Ocean University of China
基金
中央高校基本科研业务费专项(202013028)资助。
关键词
亚中尺度非地转运动
季节变化
能量串级
地转运动
submesoscale ageostrophic motion
seasonal variation
energy cascade
geostrophic motion
