#### Mingshi Yang

##### New member

I would like to know how should potential temperature tendencies be interpreted.

I understand that there are several tendency terms attributed to microphysics (h_diabatic) / cumulus (rthcuten) / radiation (rthraten) / PBL (rthblten) etc., plus an advection tendency term (rthften). The sum of these terms are consistent with change of potential temperature ∂θ/∂t.

However, it seems like the change of potential temperature ∂θ/∂t is not straightforwardly partitioned as dθ/dt (sum of first 4 tendencies) - V·∇θ (advection tendency) in the model output, as the advection tendency term seems very different from manually calculated - V·∇θ in three dimensions.

Could anyone explain or clarify what do the terms physically represent? Thank you!