چكيده لاتين :
The main objectiveofa research program, whoseoutput is presented here, has been to estimate"Ventilation Coefficients", a critical parameter in determiningair pollutionconcentration near the surface ground which signifies the ability for natural ventilation of an air shed in an urban
or rural area. Relevantmeasured data from the city of Tehran has been usedto calibrate and further demonstrate the validity of the mathematical model developed. Since most polluted mega cities require significant air pollution modeling activities, capableofproviding relativelyreliable outputs, calculating such highly important parameter is byfar the most important outcomeofthis research. The Ventilation Coefficients havebeenestimatedassuming normal adiabaticlapserates and utilizing
ten-year daily atmospheric radio-sound data. Mean Maximum Mixing Depth, Wind Speed at Mean Maximum Mixing Depth, and the VentilationCoeffi.cients have beencomputedand as a result it has
been noted that despitethe fact that Mean Maximum Mixing Depth peacksin June and WindSpeed at Mean Maximum Mixing Depth reaches its maximum in April, this has caused the Ventilation Coefficientto remain at its peack almost constant overApril-June time span. It mayalso be observed for an urban area such as Tehran, the VentilationCoefficientstandsmaximum in spring at 22329.17
mvs and minimumin fallat 22329.17rn2/s.
