Data assimilation and nesting

[vero_81]

What is the difference between data assimilation and nesting?

[jacopo]

Data assimilation is an analysis technique in which the observed information is accumulated into the model state by taking advantage of consistency constraints with laws of time evolution and physical properties.

That is, you have the model, which is imperfect, and you want to correct it by means of observations with a sophisticated interpolation with (hopefully) dynamical constraints between model data and observations.

Poorly speaking, nesting is a when you put a high resolution model domain (i.e., Italy) into a larger coarse resolution model domain (i.e., Europe). The coarse resolution domain provides boundary condition for the high resolution domain (1 way nesting) or both domains exchange information at the boundaries (2-way nesting).

Data Assimilation and Nesting are definitely completely different things. So my question is:

did you mean nudging (raw data assimilation method) instead of nesting?!?