traj-plugin: Handling of vertical velocity from ecmwf/icon/..
I work in meteorological research and was really thrilled to test out the trajectory plugin for windy. It's lightning fast, it has many settings to tweak, and it's just pure fun!
However, I have one question. It confuses me how vertical movement is treated. Of course, you can set ascend or descend rates (m/s), i.e. for use in balloon flights. But I wonder, are these rates absolute (m/s relative to ground), or relative to the surrounding air masses, which obey a large-scale vertical velocity (w, or omega) as output by the models?
Asked differently: If I set the ascend/descend rates to 0 m/s, will the trajectory plugin still simulate ascend/descend rates of the air mass themselves?
Example: I start a trajectory at lon0/lat0, at 2000m. Ascend/descend are set to 0 m/s. Will the air mass then always stay at 2000m, and only U/V at 2000m are used and not omega?
In case omega is not implemented: would this be feasible in future releases?
Thank you a lot, it's really a pleasure using your many plugins!
The reason why I am asking is that air masses prefer to move on isentropes. So if you e.g. have warm, lower-latitude air masses moving towards the poles, there can be quite high ascend rates of the air masses themselves. This also happens in warm conveyor belts, ahead of the warm sector of mid-latitude cyclones.
And as wind speed & direction are obviously nonuniform with altitude, you can end up in complete different U/V winds. Erros then add up if you calculate trajectories over several days.
Thank you for using the plugin. Unfortunately, as far as I know, the vertical speed (w) is not provided by the backend.
The trajectory remains at the selected pressure level.
I agree, It would be really cool to include vertical movement.
@rittels Thank you for the clarification! For cases with reduced vertical velocity, the trajectories are still highly valuable. And fun to work with. Best