Maps of 3D LCSs for 30 Mar 1200Z to 2 Apr 1200Z 2019, Issued 30 Mar 2019

The following figures show the 3D Finite-Time Lyapunov Exponents (FTLEs) on the surface in the domain, at different times. These 3D FTLEs are for a time window of 6 or 96 hours for the forecast of 30 March 2019 to 2 April 2019.

The figures below show the 3D FTLEs in the domain, at different times. These FTLE computations are for a time window of 6 or 96 hours for the forecasts on the dates as specified. The flowmaps were calculated using a PDE-based approach with 5th order spatial and 3rd order temporal schemes, and a novel composition based approach.

The 3D FTLE field specifies the amount of stretching of the flowmap in the considered time interval. Specifically, the forward / backward 3D FTLE is a logarithmic scaling of the dominant singular values of the forward / backward flowmap with the time duration of interest. The forward FTLE ridges thus highlight codimension-one manifolds (curves in 2D, surfaces in 3D) that repel particles starting on either side, whereas the backward FTLE ridges highlight codimension-one manifolds that attract particles towards the ridge that originally start far apart.

As a reminder, 12:00Z = 13:00 CET, i.e., CET is 1 hour ahead of Zulu time.

Calypso Domain (1/200 deg resolution)

96-hr Forecast 3D FTLE at 4 meters depth on April 2 1200Z

Date	12:00Z
April 2 (Forward)
April 2 (Backward)