Maps of 3D LCSs for 31 Mar 1200Z to 3 Apr 1200Z 2019, Issued 31 Mar 2019

The following figures show the 3D new_FTLEs on the surface in the domain, at different times. These new_FTLEs are for a time window of 6 or 96 hours for the forecast of 31 March 2019 to 3 April 2019.

The figures below show the 3D FTLEs in the domain, at different times. These new_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 new_FTLE field specifies the amount of stretching of the flowmap in the considered time interval. Specifically, the forward / backward 3D new_FTLE is a logarithmic scaling of the dominant singular values of the forward / backward flowmap with the time duration of interest. The forward new_FTLE ridges thus highlight codimension-one manifolds (curves in 2D, surfaces in 3D) that repel particles starting on either side, whereas the backward new_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 new_FTLE at 4 meters depth on April 3 1200Z

Date	12:00Z
April 3 (Forward)
April 3 (Backward)

6-hr Forecast Forward 3D new_FTLE at 4 meters depth on four time instances for March 31 1200Z - April 2 0600Z

Start Date	12:00Z	18:00Z	00:00Z	06:00Z
March 31
April 1

6-hr Forecast Backward 3D new_FTLE at 4 meters depth on four time instances for March 31 1200Z - April 2 0600Z

Start Date	12:00Z	18:00Z	00:00Z	06:00Z
March 31
April 1