Meteorological data Hourly records of meteorological
parameters, such as wind speed and direction,
and temperature, were collected from the environmental
data records as available with the mines’ authority.
Data on hourly mixing heights and stability
classes were taken from published literature (NEERI,
1990). However, some special meteorological data
such as Monin-Obukov length, surface friction length
and surface friction velocity are required for modeling
of open pit sources. These were processed from the
basic meteorological data using the PCRAMMET
meteorological data processing utility of USEPA. The
first 24 hours of meteorological data used in the
model are shown in Table 9.