Backgound

Heat domes

Find out how heat domes are created by high-pressure systems, and how they prevent precipitation and air circulation, causing prolonged temperature peaks.
June 29, 2023
6-9 minutes

Introduction

Rising global temperatures due to climate change have massively increased both the number of extreme weather events that have occurred in recent years and their intensity. One such effect is the proliferation of heat domes, a meteorological phenomenon that occurs when a vast area of high atmospheric pressure traps hot air in a region. The dome inhibits rainfall and airflow and thus causes massive and prolonged spikes in temperature, which can endanger citizens, disrupt ecosystems, and strain infrastructure systems.

maps showing us the creation a the weather phenomenon called heat domes

What is a heat dome ?

Heat domes occur when high-pressure systems settle over one area for an extended period of time. High pressure systems are areas that have higher atmospheric pressure than their surroundings, and therefore constantly transport air into surrounding, lesser dense areas. The air in a high pressure system typically flows downward, which inhibits warm and low-density air from rising, and instead making it accumulate at the surface. Thus if a high-pressure system rests over one area for a long period of time, the trapped and stationary air forms a dome-like structure, which prevents heatwaves from dissipating and causes temperatures to soar. The geographical features surrounding an area, such as mountains or coastal ranges, can also advance the formation and persistence of a heat dome by restricting cool airflow from nearby regions.

Effect on human life

The effects of the presence of a heat dome are far reaching. Humans, particularly vulnerable populations such as the elderly, children, and those with pre-existing conditions, can sustain serious injuries from prolonged exposure to extreme heat. Heat exhaustion and heatstroke are just some of the many heat-related illnesses these spikes in heat waves can cause. Additionally, heat domes worsen air quality, as the static trapped air stops pollutants from dissipating, which can be detrimental to respiratory health.

Effect on ecosystems

Heat domes also negatively effect Earth's ecosystems. Intensified heat waves increase the likelihood of forest fires, which poses a threat to the habitats of animals, plants, and humans alike. The drastic change in temperature also distresses plants, which can diminish plant yields and water supply, and therefore have long-lasting effects on biodiversity and food security.

Effect on infrastructure

Heat domes significantly strain infrastructure systems, primarily because they create an overload of demand for electricity and other materials to counter act the heat. Increased demands for air conditioning, for example, can overload power grids and lead to widespread blackouts, further deepening the problem. In the same vein, increased demands for water can deplete already strained water resources. Additionally, prolonged heat causes almost all solid material to expand, which can lead to the structural damaging of roads, bridges, and buildings.

Exacerbation due to climate change

With the onset of a rapidly warming Earth, heat domes, along with other severe weather events, have become more frequent and more intense. Climate change directly facilitates worsening heat domes for a variety of reasons. Firstly, the heightened amount of greenhouse gases in the atmosphere trap more heat on the Earth's surface, which increase the likelihood of extreme weather events and prolongs them. Additionally, the increase in heat leads to the melting of regions of snow and ice, which vastly decreases the surface area meant to reflect sun light back into space (known as the albedo effect). A decreased albedo effect in turn leads to even more heat trapped on the Earth's surface, further exacerbating the rising temperature and extreme weather. Climate change also alters atmospheric circulation patterns such as the jet stream, which directly effects heat domes in particular because of their connection to patterns of air movements. According to meteorologist Randy Adkins, as the temperature climbs, it will likely cause the jet stream to become more “wavy,” meaning that it will linger in certain places longer rather than just continuing on its original path with no detours. This “lingering” will no doubt lead to more heat domes, and thus more disastrous heat waves.

Conclusion

To conclude, heat domes are a phenomenon that occurs when a high pressure system stays in one area for an extended period of time, trapping warm air at the surface and leading to sustained spikes in temperature. These spikes pose huge risks for the people and animals living in affected areas, as well as city infrastructure. Though other factors such as the natural climate variability and local weather patterns also contribute to the formation of heat domes, it is important to highlight their magnification due to climate change. Therefore, in order to address heat domes and their effects, it is imperative that governments, businesses, and individuals take meaningful steps toward ameliorating the swiftly heating temperature of Earth. In the meantime, communities should better prepare themselves to handle heatwaves, including the implementation of early warning systems, heat safety campaigns, and social support networks. Additionally, it is imperative to establish of cooling centers in urban areas to both equitably assist those who do not have access to air conditioning, as well as diminish demand to prevent widespread blackouts. Cities should also seek to implement urban planning strategies aimed at dealing with extreme heat, such as increasing green spaces and increasing natural ventilation in buildings.