object_type

[Alonso112358]

What would be the coefficient number for a oceanographic buoy in the opendrift leeway code? We started to use this code recently and we have had problems if we use object type 67.

[knutfrode]

For a surface buoy I would rather use OceanDrift with wind_drift_factor of 0.03, or 0.01 for a Code drifter with sail at 1m depth

What problem do you get with Leeway and category 67?

[Alonso112358]

Thanks for the fast reply,

The problem is the following: When we perform the leeway code using object_type 67 the resultanting plot is anomalous , as you can see in the figure:

[image: image.png]

[image: image.png]

On the other hand, When We perform the leeway code using another object_type(for example object_type = 4), We get acceptable results according to the expected trajectory, s you can see it [image: image.png]

That's why we're asking what is the best number to use for an Oceanographic Buoy

Regards Eugenio San Martín R.

El jue, 6 abr 2023 a las 15:54, Knut-Frode Dagestad (< @.***>) escribió:

For a surface buoy I would rather use OceanDrift with wind_drift_factor of 0.03, or 0.01 for a Code drifter with sail at 1m depth

What problem do you get with Leeway and category 67?

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[knutfrode]

Cat 67 is simply following current with no windage, and rhus also no spread.. It is for code/SLDMB, but even for those it has too little windage, as 1% would be appropriate.

For surface drifter as iSphere or similar, you must use OceanDrift with wind_drift_factor of 0.03. Horizontal diffusivity can be specified to get some spread