全球中尺度涡旋分裂合并现象的特征统计研究

Statistical Characterization of Global Eddy Splitting and Merging Events

中尺度涡旋分裂与合并过程等涡旋之间相互作用的研究是海洋学研究的热点。本文以Eddy Graph方法为基础,基于海表面高度异常数据,利用高效率并行计算方法,构建全球中尺度涡旋分裂与合并追踪数据集(Global Eddy Graphs, DOI:10.12237/casearth.63369940819aec34df2674d8)。基于此数据集,本文开展了对全球涡旋分裂合并统计特征的研究。研究表明,在涡旋的生命周期中,分裂与合并现象普遍存在。将分裂与合并纳入涡旋追踪过程,能够将几条简单线性的涡旋轨迹连接在一起,找出涡旋真正的起止点与生命周期,具体表现为起点聚集在大洋海盆东岸,终点聚集在大洋海盆西岸;长寿命涡旋占比与平均寿命均有提高。此外,本文还对涡旋分裂合并典型事件进行筛选与统计,对分裂合并过程中涡旋内部的海表面温度和海表面盐度进行归一化与复合平均,探究了涡旋分裂与合并现象对海表面温度与海表面盐度的影响。

Eddy interactions,including typical splitting and merging processes,are a popular research focus in oceanography.Based on the method of Eddy Graph,this paper applies parallel computing method on sea surface level data to construct the global eddy splitting and merging identification and tracking dataset(Global Eddy Graphs,DOI:10.12237/casearth.63369940819aec34df2674d8)and publishes the dataset for the first time.Based on Global Eddy Graphs dataset,the statistical characterization of the global eddy splitting and merging process are studied.This paper shows that the phenomena of splitting and merging are common in the life cycle of eddies.Taking the split and merge into the eddy tracking process,several simple linear trajectories can be connected together,which can help to find out the real starting and ending points and life cycle of the eddy.It is shown that the starting points are clustered in the east coast of the ocean basin,and the ending points are clustered in the west coast of the ocean basin.The proportion and average life of long-lived eddies are increased.In addition,the typical events of eddy splitting and merging are filtered and statistically analyzed,and the sea surface temperature and sea surface salinity within eddies during the process of splitting and merging are normalized.The effects of eddy splitting and merging on sea surface temperature and sea surface salinity are investigated.