Heat Dome

Subject: Geography

Section: Climatology

Context: ‘Heat domes’ have also been associated with unusually warm periods in India, Bangladesh, China and some other Asian countries.

More on the News:

Places across the southwest and eastern parts of the United States recorded temperatures as warm as those seen in late June or early July, and the unusual warming was caused by a phenomenon known as ‘heat domes’
‘Heat domes’ are natural phenomena that have also been associated with unusually warm periods in India, Bangladesh, China and some other Asian countries.
This season’s first heat dome set off heatwaves in as many as 48 states in the US and fears of wildfires loom large.
Over the years, heat domes have created some of the most fatal heat waves in North America, among other regions. Creating records for some of the highest temperatures ever recorded in the continent, these waves have caused thousands of deaths.
Stopping heat domes from forming altogether is not possible, as they are a natural weather phenomenon. But as the threat of climate change continues to creep up, heat domes are getting more intense.

Heat Dome:

A heat dome is a type of high-pressure system that forms over a large area in the atmosphere, and causes extremely hot and dry weather conditions. The system traps hot air and prevents it from flowing to rise and cool.
This air then becomes compressed and heats up, leading to a dome-shaped area of hot air that can persist for several days or even weeks.
Heat domes can cause dangerous heat waves causing the temperatures to shoot up.
Due to climate change, heat domes have not only become more frequent but also a lot more intens The rising temperatures and changes in weather patterns are creating conditions that are assisting their formation.

Causes of Heat Dome:

Change in Atmospheric Pressure: Heat waves begin when high pressure in the atmosphere moves in and pushes warm air toward the ground.
- High-pressure systems often bring clear skies, which means there is less reflection of sunlight and more absorption of heat. Locations with a lot of land and relatively dry air, such as plains and deserts, serve as a favourable condition for heat domes to form as well.
Change in Ocean Temperature:
- In the process known as convection, the gradient causes more warm air, heated by the ocean surface, to rise over the ocean surface.
- As prevailing winds move the hot air east, the northern shifts of the jet stream trap the air and move it toward land, where it sinks, resulting in heat waves.
Climate Change: Climate change has led to warmer background temperatures, exacerbating the high-pressure system.

Impact of Heat Dome:

Heat-related illnesses: Heat domes can cause a spike in heat-related illnesses such as heat exhaustion, heat cramps, and heatstroke. Vulnerable populations such as the elderly, children, and those with pre-existing medical conditions are at a higher risk.
Wildfires: The high temperatures and dry conditions caused by heat domes can increase the risk of wildfires. The heat can also exacerbate the spread of fires.
Crop damage: Heat domes can cause crop damage due to high temperatures and drought conditions. This can lead to lower crop yields and economic losses for farmers.
Infrastructure damage: High temperatures can cause damage to infrastructure such as roads, buildings, and power lines.
Water shortages: Heat domes can lead to drought conditions, which can cause water shortages and impact water supplies for both people and wildlife.
Air pollution: High temperatures can lead to increased levels of air pollution, which can exacerbate respiratory problems and other health issues.

Combating Heat Dome:

Reducing greenhouse emissions: Transitioning to renewable energy sources, improving energy efficiency and promoting sustainable transportation, can be measures in achieving a reduction of greenhouse gas emissions, as it is critical to mitigating the impacts of heat domes in long terms.
Investing in green infrastructure: Cities can invest in green infrastructure, such as parks, green roofs, and tree planting, which can help reduce the urban heat island effect and provide cooling benefits.
Implementing building codes and standards: Building codes and standards can help ensure that new buildings are designed to withstand extreme heat and maintain indoor comfort during heat waves.
Reducing heat-trapping surfaces: Cities can take steps to reduce the amount of heat-trapping surfaces, such as asphalt and concrete, which can exacerbate the urban heat island effect.
Enhancing public education and outreach: Educating the public about the risks of extreme heat and how to stay safe during heat waves can help reduce the incidence of heat-related illness and mortality.