9.3.3. Tips and recommendations - Vertical Layers
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CMAQ redefines the vertical coordinates to monotonically increase with height, a capability necessary to handle a generalized
coordinate system.
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MCIP may be used to reduce the number of vertical layers by collapsing layers (no interpolation capability is provided).
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Defining the vertical layering structure for CMAQ applications is complicated, and model results are sensitive to the number
and definition.
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A six-layer vertical grid definition, such as the one provided with the tutorial, is not recommended for regulatory purposes
because this resolution is very coarse.
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Increasing the number of vertical layers increases the CPU time and the computational complexity.
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Computational limits arise from the Courant number limitation of vertical advection and diffusion processes. When using K-theory,
a very shallow layer definition increases CPU time tremendously under the convective conditions.