The heat in parts of Mexico, Central America and the Caribbean has reached sweltering levels in recent days. And this largely due to an extreme phenomenon: a heat dome. The inhabitants of Mexico City have experienced an unusual heat wave that has brought temperatures to near record high levels.
Last Thursday, the forecast of 33°C is close to the historical maximum of 33.8°C, recorded in 1998. In other cities in the Mexican southeast, where high temperatures are usually recorded more regularly, the thermometer even exceeds 40°C.
Similar forecasts have been given for cities in Central America and the Caribbean
In San Juan, Puerto Rico, their authorities issued an “excessive heat alert” last Thursday due to the high temperatures and dry weather that, together with the humidity, generated a thermal sensation of more than 40°C.
A kind of “triggered” thermometer
Although there are several factors that explain these temperatures in each region, a phenomenon that has crossed the northern hemisphere known as a “heat dome” has caused temperatures to soar in the affected areas, according to experts. “The dome is what produces such a severe heat wave”, meteorologist Alberto Hernández Unzón explained to the press in Mexico last Wednesday. “It is an express pot”.
A heat dome forms in an area of high atmospheric pressure when hot air is pushed downward and becomes trapped in one place. This causes temperatures to soar in a wide region where it is produced; it is essentially a hot air mass stubbornly rooted in place, trapping those inside at ground level in a prolonged heat wave.
Scientists believe that these events are caused by a sudden change in ocean temperatures. In turn, rising water temperatures warm the air, and winds push that heat onto land.
Once the hot air reaches land, it is trapped by a high-pressure system, forming a dome flanked by low-pressure systems on either side. The high pressure further heats the air column by compressing it, effectively acting as a dome. Extreme heat events occur within the natural variation of climate due to changes in global weather patterns.
Global warmingeffect
However, the scientists point out that the increase in the frequency, duration and intensity of these events in recent decades is clearly related to the observed warming of the planet and can be attributed to human activity.
Emissions caused by burning fossil fuels have been trapping heat in the atmosphere since the dawn of the industrial age. This extra heat is not distributed evenly around the world and causes extreme weather events, such as intense heat waves. And unless global emissions are reduced, this cycle will continue.
