Diel Vertical Migration of larvae

[aakimova]

Dear Knut-Frode,
first of all, thank you very much for developing and maintaining this nice tool. I've used it recently for a publication about larval drift (under review now) and found it very appealing. Now I'm thinking to use it for another study, where I want to compare passive particle drift with different sceanrious (possitive and negative buyoncy, diel vertical migration, etc). As fas as I see, there is no module for the diel vertical migration in OpenDrift. Am I right? If so what would your suggestion to develop such application: shall i use the OceanDrift module as the base or the PelagicEggDrift module?

[knutfrode]

Hi,
We are happy that you found OpenDrift useful for your work, and we can list your paper here when accepted: https://opendrift.github.io/references.html

I am not a biologist, so the PelagicEgg and LarvalFish are regarded as "community modules".
These are both "thin wrappers" around OceanDrift which contains the common things like the vertical mixing.
PelagicEgg is probably too simplistic, and LarvalFish has a very simplistic approach for diurnal migration:
https://opendrift.github.io/_modules/opendrift/models/larvalfish.html#LarvalFish.larvae_vertical_migration

But there is a new extended version larvalfish_extended that I guess would be the best starting point for your case.
https://github.com/OpenDrift/opendrift/blob/master/opendrift/models/larvalfish_extended.py
This uses the internal method solar_elevation and should be straightforward to customize any desired diurnal behaviour.

In the future these three modules should probably be merged into one common biological module.

[aakimova]

Cool! Thanks a lot for the prompt reply. I'll check the larvalfish_extended. I'll send you the reference to the study, as soon as the paper is out there (hopefully).