GEM：Dynamical Tracing Model for Oceanic Mesoscale Eddies
Genealogical Evolution Model (GEM) is an efficient logical model used to track dynamic evolution of mesoscale eddies in the ocean. It can distinguish h different dynamic processes (e.g., merging and splitting) within a dynamic evolution pattern, which is difficult to accomplish using other tracking methods. To this end, GEM first uses a two-dimensional (2-D) vector rather than a scalar to measure the similarity between eddies, which effectively solves the ‘‘missing eddy” problem (temporally lost eddy in tracking). Second, GEM uses both parents and children in tracking, and the dynamic processes are described as birth and death of different generations. Additionally, a look-ahead approach with selection rules effectively simplifies computation and recording. All of the computational steps are linear and do not include iteration. Given the pixel number of the target region L, the maximum number of eddies M, the look-ahead time steps N, and the total number of time steps T, the total computation complexity is O (LM(N+1)T). The tracking of each eddy is very smooth because we require that the snapshots of each eddy on adjacent days overlap one another.