Convert Trajectory to Xarray produces format incompatible with ERA5 data

[robert-DL]

Hi all,

I am wondering why convert_trajectory_to_xarray outputs a xarray with dimensions [prediction_timedelta, time, ...]. This seems odd to me as we can concatenate along the time dimension. The timedelta between two steps can be computed via time[i + k] - time[i], so I do not see a reason to have this distinction between prediction_timedelta and time. This is also in contrast to the data stored for training (original ERA5 as well as predictions from deterministic models).

Best
Robert