Vertical averaging/interpolation

[ecomodeller]

Should observations be:

1. compared to the model value in a given grid cell without interpolation
2. compared to model values interpolated to the depth of the observations
3. observed values averaged to match model grid

This is a common source of discussion in assessment of biogeochemical models.

Example of (hypothetical) observed data from some sensor along with model on a discrete non-equidistant vertical grid

The same observations, now averaged for each model grid cell.

[dhithu]

I guess this relates to how we do in the temporal domain, where (I think) we normally interpolate the model result to fit the observation. I guess, because the observation is considered "a data point of truth" and also because the model normally has a higher temporal resolution than the observation. For a vertical profile I guess both observation and model result could have the higher resolution (although models become increasingly finer), but none-the-less I would say that your item 2 would be the most intuitive way to go.