Environmental Assessment for Qurayyat Province in Northern Saudi Arabia Part I- Determination of Atmospheric Stability & Boundary Layers

Abstract

Knowledge of the atmospheric boundary layer (ABL) height is of great importance in the prediction of the local air quality. It can provide information about lower atmospheric transport and dispersion of pollutants and it is essential for developing and adapting dispersion models, which are usually used to study pollutants released from different sources. Practically, the measurements of ABL heights utilizing radiosonde or mobile sodar are not available locally. Therefore, empirical formulae are developed and used in computer programs to estimate ABL heights for our local conditions.

The hourly climatic data has been obtained and analysed to declare the joint frequency distribution of winds, different stability classes and ABL height during seasons of 2009-2012 at Qurayyat Province (lat/long 31.417 N 37.267 E & elevation of 499 m) in Northern Saudi Arabia.

Analyses of the results show that the wind was blowing almost from NW, and stability of type D (neutral) was dominant during the period. The height of ABL is strongly influenced by the dominant stability conditions and wind speed regime in addition to the solar radiation. Comparisons of ABL height among different seasons and years are also given.