Vertical interpolation of meteorological variables.

The present study demonstrates that the choice of an appropriate interpolation scheme can become a critical issue for the skill of a low-resolution prediction model. First we show that the interpolation scheme, when applied to more than one meteorological variable, should satisfy the balance requirements that exist between these variables. Next we provide evidence indicating that interpolation schemes used to convert p- into sigma-coordinates, and then back into p-coordinates, do not necessarily replicate the original, observed fields. Because of the limitations of certain interpolation procedures, even a correct model prediction may exhibit low predictive skill because of errors introduced in this final coordinate transformation process. -from Authors