We planned to use the DREAM-Eta and
WRF-NMM-dust models contributed by Univ.
of Arizona in the
beginning of the project. Because of Dr. Dazhong Yin left at the beginning of
the project, funding resource to Univ.
of Arizona (including for Peja and Nickovic) and most of George Mason Univ.
(Jibo) resources for this project were redirected to finalize/reconfigure the
DREAM-Eta 8 bin (the 8-particle-size-bin version of DREAM-Eta, developed by
Nickovic and Peja), and also to develop a new model based on the NCEP NMM
model. The new model leverages theoretical knowledge from Nickovic and was
developed by Peja in rewriting from scratch line-by-line with Jibo virtually
side-by-side. We refer to the new NMM-based dust model as NMM-dust.
on-line with the NWS Eta operational forecast model. The Eta model is defined on the semi staggered
Arakawa E grid and uses the technique for preventing grid separation in
combination with split-explicit time differencing. The step-mountain Eta model has shown considerable
skill in forecasting severe storms, but is of a spatial resolution too coarse
for many potential applications. The horizontal grid spacing of DREAM-Eta 8
particle is 1/3 of a degree. With current horizontal resolutions, models used
for numerical weather prediction (NWP) are approaching limits of validity of
the hydrostatic approximation. The Eta model was replaced in NWS operations by
a Non-hydrostatic Mesoscale Model (NMM), which has higher resolution and
greater computational efficiency (Janjic et al., 2001, Janjic 2003), and NMM
was now replaced by WRF-NMM for operation at NCEP.
The NMM-dust model is used to test concepts of
interoperability with DREAM-eta and supercomputing for operation over the U.S.
The NMM-dust is executable in parallel mode on HPC that is based on the NCEP_NMM
weather forecasting model. The NMM-dust model can produce higher resolution
results for weather forecasting and can parallel run on HPC to obtain higher
resolution dust simulation results up to about one KM2.
testing was performed through the following steps:
Initial tests were accomplished
by specifying first the elevated and then the surface point source with
arbitrary values of injected dust concentration. Only model dynamics were used
to test model performance, i.e. horizontal and vertical advection and
horizontal and vertical diffusion were used to disperse dust from the point
When expected results were
obtained from the previous step, the second phase replaced the point source
with the geographically distributed dust sources, specified according MODIS (MOD12)
land cover data.
Final tests included all dust
components (dynamics and source/sink components) and results were compared with
the DREAM-Eta with the same domain/resolution specification; very comparable
features of the dust fields in both models were obtained.