• A heat dome occurs when the atmosphere traps hot ocean air like a lid or cap.
• As per National Oceanic and Atmospheric Administration (NOAA), USA, a heat dome is created when strong high-pressure atmospheric conditions combine with weather patterns like La Niña.

Causes of Heat Dome Formation:

1. Ocean Temperature Gradient: Heat domes originate from significant changes in ocean temperatures, promoting convection. This leads to warm air rising over the ocean surface.
2. Jet Stream Effect: Prevailing winds transport the heated air eastward, where the jet stream's northward shift traps and directs it toward land. Here, the air sinks, resulting in heat waves.
3. Atmospheric Pressure Shifts: High-pressure systems in the atmosphere drive warm air downward, intensifying heat. Heat rising from the ocean amplifies this effect, altering weather patterns, reducing wind and cloud cover, and creating stifling conditions.
4. Climate Change Impact: Global warming has exacerbated heat waves, making them hotter, longer-lasting, and more frequent. Scientists attribute today's severe heat waves to human-induced climate change.

Heat Domes and their impact on Human Beings

• A heat dome can have serious impacts on people, because the stagnant weather pattern that allows it to exist usually results in weak winds and an in- crease in humidity. Both factors make the heat feel worse - and become more dangerous because the human body is not cooled as much by sweating.
• All these, increases the risk of heat illnesses and deaths with global warming, temperatures are already higher, too.
• The heat index, a combination of heat and humidity, is often used to convey this danger by indicating what the temperature will feel like to most people. The high humidity also reduces the amount of cooling at night.
  One of the worst recent examples of the impacts from a heat dome with high temperatures and humidity in the U.S. occurred in the summer of 1995, when an estimated 739 people died in the Chicago area over five days.

Study

• A 2022 study found that this heat dome was amplified by climate change and it could become a once-in-10-year event if global temperatures aren't kept under two degree Celsius above pre-industrialization levels.