[MITgcm-support] weird temperature signal using 3D floats with the FLT package

[David Ferreira]

Hi Steffie,
Does you set up have slopping boundaries? Look like the floats are closely hugging the boundaries and I'm wondering if they may be bumping into topography, hence the jumps. I realize you mention no links between the jumps and location/depth, but I'm not sure how the float package deals with the topography.
cheers,
david


________________________________
From: Steffie Ypma - CITG [S.L.Ypma at tudelft.nl]
Sent: Friday, December 16, 2016 10:51 AM
To: mitgcm-support at mitgcm.org
Subject: [MITgcm-support] weird temperature signal using 3D floats with the FLT package

Hi all,

I have released 3D floats using the FLT package in a very easy set up of the MITgcm. I have a 7.5km horizontal resolution in the horizontal, and 20 levels in the vertical till a depth of 3000m. The basin is closed and a cyclonic, warm boundary current is created by restoring temperature in the south-east corner between the island and the coast. There is no surface forcing. Density is calculated using the linear equation of state and is only dependent on temperature.
The particles are released using the online mode, just after the restoring area at y = 40, x = 140:160 and at all depth levels, integrated for the duration of 6 months. The figures show:

- temperature.png: surface temperature after 6 months
- velocity.png: absolute velocity (speed) at surface after 6 months
- trajectories.png: the path of all particles
- T_change.png: the temperature change over time of the particles that show cooling or warming > 0.5  degrees (24 out of the 181 particles).

I am wondering what could be the cause of the particles jumps in the temperature. I have so far not found a correlation between this subset and other fields like change in depth, location etc.
Any ideas are welcome.

Cheers,
Steffie
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