open boundary problem

[xujingbo7]

hi，
I have a question about opening a boundary. For example, my boundary is set at 123°N. If a particle hits this boundary, the default situation in the model is to stop the particle, but the particle state is still "active". I want this particle to leave this area and make this part of similar particles appear in a "stranded" state. Is there any way?

[knutfrode]

Hi,
This depends on the default configuration of the module you are using:
If fallback values for currents (and possibly wind) is not None, then particles will get this value (default 0 for some modules) instead of being deactivated.
If you want to deactivate elements outside coverage of your readers, you can do:
o.set_config('environment:fallback', {'x_sea_water_velocity': None, 'y_sea_water_velocity': None})

[xujingbo7]

thanks! 许敬波 ***@***.***

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---- Replied Message ---- From Knut-Frode ***@***.***> Date 4/23/2024 21:34 To ***@***.***> Cc ***@***.***>, ***@***.***> Subject Re: [OpenDrift/opendrift] open boundary problem (Discussion #1278) Hi, This depends on the default configuration of the module you are using: If fallback values for currents (and possibly wind) is not None, then particles will get this value (default 0 for some modules) instead of being deactivated. If you want to deactivate elements outside coverage of your readers, you can do: o.set_config('environment:fallback', {'x_sea_water_velocity': None, 'y_sea_water_velocity': None}) — Reply to this email directly, view it on GitHub, or unsubscribe. You are receiving this because you authored the thread.Message ID: ***@***.***>

[xujingbo7]

hi, I have a new problem. According to the scheme you provided, the legend of the particle arriving at the shore shows "missing_data", and it still stops at the open boundary, only this time the particle is gray. Can we not show these particles between each other in the picture? Do not include this part in the legend. 许敬波 ***@***.***

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---- Replied Message ---- From Knut-Frode ***@***.***> Date 4/23/2024 21:34 To ***@***.***> Cc ***@***.***>, ***@***.***> Subject Re: [OpenDrift/opendrift] open boundary problem (Discussion #1278) Hi, This depends on the default configuration of the module you are using: If fallback values for currents (and possibly wind) is not None, then particles will get this value (default 0 for some modules) instead of being deactivated. If you want to deactivate elements outside coverage of your readers, you can do: o.set_config('environment:fallback', {'x_sea_water_velocity': None, 'y_sea_water_velocity': None}) — Reply to this email directly, view it on GitHub, or unsubscribe. You are receiving this because you authored the thread.Message ID: ***@***.***>

[knutfrode]

There is no option in the built-in plot- or animation methods to not show particles deacticated due to missing data.

Thus you can either update the plot-method to achieve what you want, or you can try the new TrajAn package which should give more flexibility to build custom plots:
https://opendrift.github.io/trajan/