The Meteorology-Chemistry Interface Processor (MCIP) converts meteorology data output from either the PSU/NCAR Mesoscale Model (MM5) or the Weather Research Forecast (WRF) model
to I/O API formatted files that are compatible with CMAQ and the Sparse Matrix Operator Kernel Emissions (SMOKE) model. MCIP automatically determines if an input file is MM5 or WRF by trying to open the file as a netCDF file. If the file can be
read as netCDF, MCIP assumes the input is a WRF dataset; otherwise, MM5 is assumed.
While most of the variables calculated in the meteorology model are simply passed through by MCIP to the output I/O API files, radiation fields and dry deposition velocities are calculated by MCIP. In addition, the user has the option of passing through the planetary boundary layer (PBL) heights calculated by the meteorology
model (recommended) or recalculating the PBL with MCIP. Environment variables in the MCIP run script control these configuration settings.
MCIP has the capability to extract both temporal and spatial subsets of the input meteorology files.
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The run script allows the user to specify the beginning and end dates/times of the MCIP simulation; these dates/times can fall anywhere within the range of the input meteorology time period.
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Two types of horizontal domain windowing are allowed with MCIP. The boundary trim option uniformly trims grid cells off each of the four horizontal boundaries of the input meteorology
grid. The non-uniform trim option specifies an offset from the lower left corner of the input meteorology domain and the number
of cells in the X and Y directions from the revised origin to extract from the input domain. More information about how to
invoke these options is provided in Section 5.7.2.4: MCIP execution options
- MCIP also provides the capability to reconfigure the vertical layer structure in the input meteorology through interpolation from
the input structure to an output structure defined through sigma coordinates in the run script. Commonly referred to as layer
collapsing, this option should be exercised with caution as it can significantly impact the conservation of energy assumption
inherent in the meteorology through its affects to the predicted wind fields.