The heat dome turns America and Europe into a pan of fire

A heat dome is a meteorological phenomenon that occurs when an area of ​​high pressure in the atmosphere forms a dome over a large area and remains there for days or even weeks. According to AccuWeather meteorologist Brandon Buckingham, this dome acts like a lid, preventing heat from escaping and blocking clouds from forming, leading to persistently high temperatures that are difficult to cool down. As warm air rises, it is blocked by a dome of high pressure. As it sinks, it compresses and heats up, creating extremely high temperatures near the surface in areas hundreds of kilometers wide.

According to the Weather Prediction Center of the US National Oceanic and Atmospheric Administration (NOAA), two heat domes are preparing to merge, which could push temperatures higher across the United States this week. The first heat dome is developing in the southwest and the second heat dome is forming over the subtropical Atlantic Ocean. They are expected to combine to form a larger heat dome covering the eastern United States on the Fourth of July holiday with temperatures above 32.2 degrees Celsius in the Great Lakes and Minnesota, while southern states such as Texas will record temperatures above 37.8 degrees Celsius. From the mid-south region to the Gulf of Mexico, the heat index could reach 43.3 degrees Celsius.

Theo USA Todaya powerful heat dome is also covering Europe, trapping the super-hot air mass blowing from the Sahara desert, causing an unusual heat wave extending from the Iberian Peninsula to Western Europe. On June 23, France experienced its hottest night since 1947, after the hottest afternoon ever recorded nationwide (37.8 degrees Celsius).

Causes of heat dome

Theo National Geographicunlike heat waves, which can stem from many factors, heat domes require specific weather conditions and often originate from changes in atmospheric patterns. When these patterns disrupt the jet stream, a stream of strong winds that move quickly from west to east in a wavy pattern, areas can experience extreme weather such as heat, floods, cold, rainstorms and drought. When the north and south loops of the jet stream get too large, they slow down or stand still, causing the high-pressure system to stagnate and form a heat dome.

Ocean climate models like El Nino and La Nina could lay the groundwork for a heat dome as warmer-than-normal sea surface temperatures change air circulation. High pressure systems prevent warm air from rising, inhibiting cloud formation, creating long-lasting hot and dry weather. As more and more solar radiation reaches the ground, the amount of heat poured into the dome increases.

How does the heat dome move?

Heat domes tend to be stationary or move slowly, covering large areas. Its direction of movement and duration are influenced by atmospheric circulation patterns, especially the jet stream. According to Buckingham, the location of the jet stream often determines how long an area experiences a heat dome and whether cool air from higher latitudes can rush in. When the jet stream changes or weakens, the heat dome can expand in size or move to a new area. When the high pressure band is broken, the temperature will gradually decrease and the heat dome will quickly disappear.

Impact of climate change on heat dome

According to the 2023 report of the Intergovernmental Panel on Climate Change, extreme heat events, including heat domes, have become more frequent and more intense in almost every landmass since the 1950s. As ocean and land temperatures warm, the effects of heat domes are amplified. Additionally, heat and drought also drain soil moisture, leading to less evaporation and cooling.

Theo New York Timesalthough high pressure systems or heat domes are part of natural weather fluctuations, scientists warn that climate change is increasing the frequency and intensity of these extreme events. Hannah Cloke, professor of meteorology and climate science at the University of Reading, explained that warmer atmospheres act as a springboard, as heat domes develop, they come from hotter conditions and easily create heat waves.

Effects of heat dome on the human body

Hot and humid conditions inside heat domes can pose serious health risks, including clogging the body’s main cooling system, the sweat glands, according to Mostafijur Rahman, an expert at Tulane University who studies the effects of extreme weather on human health. The body cools down as sweat evaporates from the skin, but high humidity in the air prevents sweat from evaporating effectively, leading to increased body temperature, causing dehydration, exhaustion and stroke.