الانقلابات الحرارية فوق مدينة الدمام في المملكة العربية السعودية دراسة في مناخ المدن الصناعية

Abstract

The research aims to study the phenomenon of thermal inversions over the industrial city of Dammam in the eastern region of the Kingdom of Saudi Arabia for the period 2011-2022, as it is one of the important climatic phenomena associated with the conditions of industrial cities and the problems of air pollution, which are associated with this phenomenon, especially the concentration of many basic industries in this city. The search is to detect the nature of thermal inversions of their various types and the frequency of their recurrence and the duration of their stay per month in addition to determining some of their basic characteristics such as the height of the inversion layer and its thickness in addition to determining its intensity, and it was found from the analysis of radiosonde data for the mentioned period that the phenomenon is almost a semi-permanent phenomenon over the city, as the total average The survival of the surface inversion is 246 days, Its frequency increases relatively during the winter months as a result of the speed of cooling of the surface air layers compared to the upper sections of it and the record of the upper downward thermal inversion, a seasonal survival rate of 84.36 days and a frontal 13.43 days. Frontal inversion cases due to the lack of recurrence of frontal depressions passing through the region. The rate of height and thickness of the thermal inversion layer also varies, as the highest thickness of the upper inversion was reached during October and the lowest during February. As for the surface inversion, the highest thickness was recorded during January. Below in November. The highest height of the upper thermal inversions is recorded during the summer months due to the dominance of the subtropical elevation, while the surface inversion layer settles at a height of approximately 400 m. Most of the months of the year do not prevail in terms of intensity. The percentage of the number of days of survival of the surface thermal inversion varies between the seasons of the year, as the highest percentage is reached for the shallow inversion In the fall, the average solstice increased in the winter, the severe solstice increased in the summer, and the very severe solstice also during the summer. The intensity of the upper thermal inversion also varies monthly, as the highest rate was recorded in the winter season for the shallow, medium and severe inversion between autumn and winter, while the very severe inversion during the winter and spring seasons.