SurfacePresence [no units] (grid_y, grid_x): [1] where maximum oil across time and runs is greater than our surface volume threshold; [0] elsewhere.

[SusanEAllen]

[SusanEAllen]

For each run it will be 1 if surface volume is significant at any time during the run (aka > 3L), but across runs it should be the sum (and we need the number of runs).

[RachaelDMueller]

Agreed. This is what I have in mind too.