link to open access paper https://www.nature.com/articles/s43247-026-03943-9

The amplitude (A) and phase lag (D) of the M2 tidal constituent derived from SWOT and the shoreline imagery. Shoreline estimates are outlined in white. Two regional assessments are presented around Christchurch (B and E) and the Cook Strait (C and F).

“phase lag” meaning compared to a baseline tidal cycle -> how behind and out of sync is that spot of shoreline/water from the overall regional tidal cycle? 180 degrees of course meaning the tidal cycle in that spot is opposite of what it is regionally/when viewed from a zoomed out perspective