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The Dust Transport Application (DTA) uses The University of Colorado
Aerosol and Radiation Model for Atmospheres (CARMA) with MM5
daily weather forecast data provided by the Air Force Weather Agency
(AFWA). The model predicts the concentration and location of naturally
occurring dust and dust storms. The dust model makes 72 hour forecasts
in 3 mesoscale theaters: Saharan Africa and the Middle East (T9), Southwest
Asia, including Iran, Iraq, Saudi Arabia and Afghanistan (T4), and East Asia
covering China and Mongolia (T6). The model includes the effects of winds,
dust particle size, surface moisture and wet deposition in the predicitions.
The CARMA dust model was originally developed by Professor Owen Toon
and Dr. Peter Colarco at the University of Colorado PAOS Group. The CARMA
dust model uses a new global dust source database developed by Dr. Paul
Ginoux at GIT/NASA GSFC. The database was developed based on surface
topography associated with persistent dust emission regions observed by
NASA satellite instruments. The SRM group at The Johns Hopkins University Applied Physics
Laboratory modified the CARMA model so it could assimilate daily MM5 weather
forecast data. The model was made into an automated software package that
included display graphics and analysis tools for dust forecasting.
DTA produces a set of colored maps showing the total dust concentration
(PM10) at selected heights above ground. The dust concentration maps use a log
scale to cover concentrations from 10µgm/m³ (log(10)=1) as purple on the plotting
scale, to >5,000 µgm/m³ (log(5,000)=3.5), which are shown as red regions on the
plots. Dust concentrations in the atmosphere vary from less than 50 µgm/m³ (normal
atmosphere), >100 µgm/m³ under hazy conditions, 1000 µgm/m³ (reduced visibility,
very hazy), to 5000 µgm/m³ and higher in dust storm conditions. Note that severe
dust storm conditions have been reported with concentrations exceeding 100,000 µgm/m³!
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