Currently,
two distinct versions of Weather Research and Forecasting (WRF) model
are under development
by NCEP and NCAR. Within the next couple of years, NOAA/NWS will be replacing
the current Eta model with the version of WRF that contains the dynamic
core of the NWS
non-hydrostatic mesoscale model (hereafter designated as WRF/NMM). Recently NOAA (NWS and
OAR) has been testing an initial capability for numerical air quality
forecasting. The backbone of
this initial capability is a computer modeling system based on the NWS
Eta mesoscale
meteorological forecast model and the NOAA/EPA Community Multiscale Air
Quality (CMAQ) model. Because the Eta model will be replaced by
WRF/NMM in the near future, there is a need to
build the air quality forecast capability by linking CMAQ with WRF/NMM. The fully compressible
governing set of equations used in CMAQ can maintain dynamic
description of the WRF just by
replacing the Jacobian defining the vertical coordinate transformation
and by carefully
writing out dynamic and thermodynamic variables. In
this presentation, I will discuss issues
involved in linking CMAQ to the dynamics and grid structure of WRF/NMM. We will contrast the
different linkage methods between the WRF/NMM and WRF/EM.