加利福尼亚海湾及其邻近海域亚中尺度现象的地震海洋学研究  

Seismicoceanography research of submesoscale phenomena in the Gulf of California and its adjacent regions

作　　者：梁智超 宋海斌[1] 范文豪 杨顺 LIANG ZhiChao;SONG HaiBin;FAN WenHao;YANG Shun(State Key Laboratory of Marine Geology,School of Ocean and Earth Science,Tongji University,Shanghai 200092,China)

机构地区：[1]海洋地质国家重点实验室,同济大学海洋与地球科学学院,上海200092

出　　处：《地球物理学报》2022年第8期3040-3053,共14页Chinese Journal of Geophysics

基　　金：国家自然科学基金(41976048);国家重点研发计划(2018YFC0310000)资助.

摘　　要：亚中尺度过程连接了中尺度与小尺度过程,在上层海洋物质垂向交换和能量传输方面起到重要的作用.在加利福尼亚湾及其邻近海域2002年采集的地震剖面上观测到了亚中尺度的涡丝,锋面和涡旋结构.理论的涡丝垂向结构为一对偶极子次级环流,由中间的高密度下沉流和两侧的低密度幅聚相向流构成,密度结构呈人字形分布的多个相向倾斜密度锋.地震剖面上中尺度涡的亚中尺度涡丝由多组相对的叠瓦状倾斜反射体构成,验证了涡丝内部密度锋的理论垂向结构.同时我们观察到亚中尺度涡旋的垂向结构及其涡丝结构,其涡丝在地震剖面上呈现为近水平的括号状反射,这种形态可能与旋涡星系的旋臂结构有一定相似性.随后计算了地震斜率谱和相对谱能量分布,通过亚中尺度涡旋和其它区域在不同波数段的能量强度差异,探讨了亚中尺度涡对能量耗散过程的影响.Submesoscale processes,which connect mesoscale and small-scale processes,play an important role in vertical material exchange and energy transfer in the upper ocean.Submesoscale eddy filaments,fronts,and eddy structures were observed in seismic profiles collected in the Gulf of California and adjacent waters in 2002.The vertical structure of the eddy filaments in theory is a pair of dipole secondary circulation,which is composed of high density sinking current in the middle and low density convergent opposite currents on the two sides.The density structure is a herringbone distribution of multiple oblique density fronts.The submesoscale eddy filaments of the mesoscale eddy on the seismic profile are composed of several groups of relative imbricate inclined reflectors,which verifies the theoretical vertical structure of the density front inside the eddy filaments.At the same time,the vertical structure of submesoscale eddies and their eddy filaments are observed.The eddy filaments are nearly horizontal bracketed reflections on the seismic profile,which may be similar to the spiral arm structure of spiral galaxies.Then the slope spectrum and relative spectrum energy distribution of the seismic profiles are calculated,and the influence of submesoscale eddies on the energy dissipation process is discussed through the energy intensity difference between submesoscale eddies and other zones in different wave number segments.

关 键 词：亚中尺度 地震海洋学 涡丝结构 加利福尼亚湾 

分 类 号：P631[天文地球—地质矿产勘探] P738[天文地球—地质学]