Abstract
During the period from June 19 to July 4, 2021, the regions of northwestern and central Libya were affected by a hot and exhausting heat atmosphere as a result of being affected by a summer weather phenomenon called the Heat Dome. This paper aims to diagnose the causes of its occurrence and how to assess its environmental effects, by following the methodology of Synoptic diagnosis and Integrated Environmental assessment. The results of the diagnosis showed that the occurrence of the phenomenon is due to the formation of a high atmospheric pressure system known as the Omega Block pattern (Ω), centered at the level of 500 hectopascals, This situation causes the activation of some influencing factors such as the emission of downdraft air currents that stimulate air compression and high temperature, a decrease in the stratospheric ozone concentration, the arrival of a large amount of ultraviolet radiation to the surface of the Earth, and increase of tropospheric ozone concentration. Climate changes affect the phenomenon and make it more frequent, longer visible, and hotter. Because the phenomenon is linked to a number of environmental impacts and negative consequences, the paper assures the importance of using the Integrated Environmental Assessment Framework model (DPSIR-Model), In order to arrange a series of stages of the development of the severity of the phenomenon, in addition to identifying risk-oriented response patterns to mitigate negative Impacts. The paper recommends Conducting a detailed study of the phenomenon, evaluating its environmental impacts, determining the effective path to guide mitigation measures, and working on issuing daily bulletins of the ultraviolet radiation intensity index during the summer period.

Key words: ظاهرة القبة الحرارية, المرتفع الجوي, نمط حاجز أوميجا, التيارات الهوائية الهابطة