Scientific analysis | Learn about the heat dome and the thermal depression and their effect by raising temperatures to record levels at times

Arabia Weather - We are still at the “Arab Weather” Center, following the repercussions of the heat wave affecting the Arab Gulf countries and several Arab countries, as at the time of writing this report, several Arab regions are exposed to high temperatures reaching the threshold of 50 Celsius, and some of them exceed that in some areas. .

Weather forecasters at the Arab Weather Center said that the reason for the significant increase in temperatures in the Arabian Peninsula is due, God willing, to the combination of several weather conditions, namely the development of a heat dome coinciding with the formation of thermal air depressions over the region.

What is a thermal dome and how does it contribute, along with the thermal depression, to raising temperatures significantly?

A heat dome is known as an atmospheric phenomenon that occurs when an area of high atmospheric pressure forms in the upper layers of the atmosphere, and with the weakness of weather systems to move in the summer as a result of weak winds or air currents, this leads to the presence of high atmospheric pressure of hot air in the high layers of the atmosphere. In a certain place for a long time, and as this process continues, this prevents any other air from entering that area. As the sun continues to heat the Earth’s surface, a thermal air depression forms above the surface. Because when the air is heated, its density decreases, and the hot air rises upward through the ascending air currents, so the high rises. The upper layer, in contrast to these rising hot currents, bounces back downward, leading to the retention of hot air in the lower layers and a significant increase in temperature. This phenomenon is known as a heat dome. As an example, a heat dome works to trap high-pressure air in one place, such as the lid of a pot during Cooking.

A thermal depression is known as a depression resulting from intense heating of the Earth’s surface. The air in contact with it heats up, its density decreases significantly, and it rises upward, causing a drop in pressure in that region. The air begins to move from areas of high pressure toward areas of low pressure to gather there, and an upward movement is formed when the air rises. To the top, it finds on its way the upper elevation, which works to reflect this air back down and to the surface, which leads to the process of trapping this air in a specific area for a long period, and the continuation of this process for a long period leads to the formation of heat waves and raising the temperature in a specific area to record levels.

The effects of a heat dome on the weather around us:

• The formation of a heat dome causes temperatures to rise significantly and may reach record and dangerous levels that may exceed 50°C, as happened in Libya on September 13, 1922 AD, when the meteorological station in Al-Aziziya in Libya recorded a temperature of 58.0°C. .
• Downdrafts in high altitudes also pollute the air and increase the percentage of dust and dirt in the atmosphere. Air stagnation and lack of renewal also lead to air pollution, which may cause harm to the public.
• Repeated heatwaves can also increase pressure on electricity grids, potentially causing power outages.
• In the agricultural sector, hot weather leads to drought in water and agricultural crops, and a significant rise in temperatures leads to forest fires, which can cause a great danger to lives and property if they break out in large areas and are lost control.