exitcode=-2 when avoidcoast=.True.?

[veronica...@gmail.com]

Hi CMS Users,

I'm working with a student using CMS with MOM5 3D velocities, and we are running into a surprising issue, losing a large percentage (20%) of particles with exitcode=-2 (i.e. particle reaches the land mask at the coastline or at topography), in spite of having avoidcoast set to .True. We are using the mixedlayerphysics option, and the exitcode=-2 appears to occur everywhere when we have mixedlayerphysics = .True., but is rare when mixedlayerphysics = .False. As far as I can tell the mixedlayerphysics option restricts random vertical shuffling of particles to within the mixed layer so should not be able to move particles to the seafloor, so we are at a bit of loss as to why the mixedlayerphysics option is affecting the number of particles getting exitcode -2.

In the past I've had particles get exitcode = -2 ONLY when they are released extremely close to topography and were advected into the seafloor in the very first timestep, which I think avoidcoast is unable to prevent, but in this case it's happening later in the run and for particles initiated far from the seafloor/coast. 

Has anyone else encountered a similar issue?

Thanks,

Veronica