Positive-Time Ftle In The Gulf Stream Computed From Ssalto/Duacs

SCII data set of positive-time finite-time Lyapunov exponent (FTLE) in the Gulf Stream calculated with velocity fields from Segment-Sol multi-missions d’ALTimétrie, Orbitographie et localisation précise/Data Unification and Altimeter Combination System (SSALTO/DUACS) absolute dynamic topography and absolute geostrophic velocity products. There are 7961 data sets: one per day from 7 January 1993 until 17 October 2014. Calculation of the FTLE is described in “Gulf Stream transport and mixing processes via coherent structure dynamics” by Yi Liu et al., submitted to JGR Oceans, 2017. The data can be uncompressed with standard tar commands. Data dimension in x and y are given in the first two lines of each set (1200x600), but are the same for each set. The grid coordinates are not included in the data set, but can be easily recreated knowing that the longitudes (x-direction) range from -89.875 (degree) to -30 (degree), and the latitudes (y-direction) range from 25.125 (degree) to 55 (degree). The data were written in a nested loop, with the y-dimension inside the x-dimension loop.本数据集为墨西哥湾流区域正时间有限时间李雅普诺夫指数（FTLE）的SCII数据集，其计算所用流场数据来自多任务测高、轨道确定与精确定位/数据整合与测高组合系统（Segment-Sol multi-missions d’ALTimétrie, Orbitographie et localisation précise/Data Unification and Altimeter Combination System，简称SSALTO/DUACS）的绝对动态地形与绝对地转流场产品。 本数据集共包含7961份数据，涵盖1993年1月7日至2014年10月17日期间的每日数据。有限时间李雅普诺夫指数的计算方法详见Yi Liu等人2017年提交至JGR Oceans的论文《Gulf Stream transport and mixing processes via coherent structure dynamics》。数据可通过标准tar命令解压。 每份数据的前两行分别给出了x、y方向的数据维度（1200×600），且所有数据的维度均保持一致。数据集中未附带网格坐标，但可通过已知的经度（x方向）范围为-89.875°至-30°、纬度（y方向）范围为25.125°至55°轻松重构得到。数据采用嵌套循环格式写入，其中y维度循环嵌套于x维度循环之内。