Atmospheric Stability and Meteorological Scenarios as Inputs to Air Pollution Transport Modeling

Meteorological scenarios concerning the data required for engineering applications of pollutant transport modeling in the low layers of troposphere are defined through a simple methodology. This involves only data at soil surface and substantially relies on the determination of atmospheric stability carried out through fictitious vertical profiles of air temperature considered as representative of the actual vertical profiles in a study area. This assumption is supported by comparisons of fictitious vertical profiles, obtained by measurements of air temperature at soil surface but at different heights above sea level, and the temperature vertical profiles observed by the radio-sounding station closer to the study area. The fictitious profiles are first used to derive the usual classes of atmospheric stability as unstable atmosphere, neutral atmosphere, stable atmosphere, thermal inversion at the surface and thermal inversion in the upper layers. Then, each scenario is determined through the classes of atmospheric stability observed at 06.00 GMT and 15.00 GMT together with the experimental data of air temperature, relative humidity, wind speed, wind direction, and cloud cover, all averaged in the period of investigation of a few years. An area of Central Italy, where the meteorological measurements for a period of 7 years were available, has been selected for this study.