Partition FieldSets?

[hblumberg]

Is it possible to partition a FieldSet into smaller FieldSets?

The motivation is that we want to create a FieldSet where the scaling factor varies by time. For example, if we have a FieldSet with two days of data, we might want to apply a scaling factor of 0.5 to the first day and a factor of 0.75 to the second day. So we were wondering if there is a way to take the original FieldSet and partition it (either by a particular time or into equal chunks).

Currently, we're thinking our best bet is to load the data into an xarray, partition it there, and then create FieldSets from the partitions. Before we implement that, we wanted to check to see if anyone here has better ideas!

Thanks in advance!

[erikvansebille]

Hi @hblumberg, thanks for your question. I don't think that what you want to do is possible out-of-the-box with FieldSets.

Options to still implement this are

1. as you suggest yourself, by using array, as you suggest. array is much more versatile than the FieldSet object of Parcels
2. by cutting the simulation into two simulations, for the first and second day separately. If you store the particle locations and then use ParticleSet.from_particlefile to create a new FieldSet and ParticleSet with the ending locations of the first day simulation as starting locations
3. by writing your own Kernel that, based on the time, uses a different advection scheme (i.e. multiplying the velocities by a different scaling factor)
4. ... (there are probably many more ways to accomplish this)

Does that make sense?

[hblumberg]

Absolutely, thanks so much for confirming our thinking and for suggesting additional approaches!