Abstract
The monitoring mid documentation of atmospheric stability are required for pollutants concentration prediction in air quality models at any location. The aim of this work is to asses how the atmospheric stability varies through the hours of the day at Qena, Egypt (26 degrees 17', 32 degrees 10', 96 m a.s.l.) using 4 years measured meteorological data (2001 - 2004) carried out by South Valley University (SVU)meteorological research station. Starting from traditional algorithms based classifying methodologies, the atmospheric stability has been estimated from the hourly values of the global solar radiation (GSR), surface wind speed (WS) and clouds amounts (CA) according to Pasquill-Gifford (P-G) stability classification. Statistical analysis of these results through the whole period of this study was employed to evaluate the general future of the atmospheric stability in the region of the study. Dispersion parameters both horizontally (sigma(y)) and vertically (sigma(z)) were also calculated at a certain downwind distance (x) for each stability class of the atmospheric conditions. The results show that 46.5%, 24.3% and 29.2% of the day hours through the study period are characterized with unstable, neutral and stable atmospheric conditions respectively.