In an unexpected twist for mid-November, an unusual surge of intensity is scorching Brazil and various corners of South America amid an unprecedented bout of sizzling weather gripping the planet.
The fervor in Rio de Janeiro, a bustling city of nearly 7 million souls, has proven to be both challenging and deadly. As temperatures soared on a scorching Friday night, a tragic incident unfolded at a Taylor Swift concert, where a woman lost her life. The heat was so relentless on Saturday that Swift had to postpone her scheduled performance for the evening.
Despite the calendar signaling spring in the Southern Hemisphere, temperatures have skyrocketed well beyond the norms, even for the impending summer, which is over a month away.
A stagnant high-pressure zone, the influence of El Niño, and the repercussions of human-induced climate change have converged to create this extraordinary outburst of intensity.
Now, let's dive into the thermometer's report...
Rio has been steeping in an oppressive blend of heat and humidity for an extended period. On the fateful Friday, when tragedy struck at the concert, midday temperatures soared above 100 degrees, with dew points, a measure of humidity, reaching the upper 70s. Any dew point exceeding 75 degrees signifies oppressive humidity.
At a dew point of 77, about 23 grams of water, or roughly 1.55 tablespoons, saturate each cubic meter of the atmosphere – a weight equivalent to approximately nine pennies.
Heat indices on Friday, a measure of how it feels factoring in humidity, exceeded 120 degrees. Weather historian Maximiliano Herrera tweeted that the intensity record reached a staggering 137 degrees in Rio's suburbs on Saturday.
The higher the intensity index, the less our bodies can rely on perspiration to cool down. This is due to the air being closer to its moisture-holding capacity. Elevated intensity indices hinder the evaporation of sweat, making it challenging to regulate internal body temperature. Left unchecked, this can lead to heat exhaustion and heatstroke.
Saturday's temperatures around Rio were not only dangerously high but also unprecedented. Rio's Jacarepaguá-Roberto Marinho Airport recorded an intensity peak of 131 degrees on Saturday morning, a result of a temperature nearing 97 degrees and a dew point of 86. Other airports in the city reported high temperatures ranging between 105 and 107 degrees.
According to Herrera, the town of Seropédica, a suburb around 25 miles west-northwest of Rio, and 15 miles inland, reached a scorching 108.7 degrees – a November record.
Record-high temperatures also swept into Peru and Bolivia. On Saturday, Tingo de Ponaza, Peru, experienced highs of 102.6 degrees, and Cobija, Bolivia, recorded 102.2 degrees – both setting November standards, as per Herrera.
The intensity first swept into Brazil about a week ago. Reports from the BBC indicated that high alerts were issued for nearly 3,000 towns and cities due to "intolerable" heat. On November 12, Rio hit 108.5 degrees, marking a record for the month.
The grip of this intensity is forecasted to ease somewhat after Sunday, but temperatures are anticipated to remain warmer than usual through the following week in central South America.
Now, let's dissect the factors fueling this extraordinary intensity...
Adding to the intensity is a counterclockwise-turning surface high-pressure system just offshore of Brazil. This system has induced warm, moist northerly winds, bringing in the kind of humidity characteristic of the Amazon rainforest. There's also a "heat dome," or a border of hot, descending air at higher altitudes. By steering away the jet stream and any inclement weather conditions, and dispersing cloud cover, it's facilitating the onslaught of scorching sunlight.
The Amazon drought also plays a role in this meteorological drama...
The intensity is further propelled by a strengthening El Niño, the weather pattern associated with warmer-than-average sea waters in the tropical Pacific Ocean.
Moreover, the frequency, intensity, and duration of extreme weather events, such as this one, are on the rise due to human-induced climate change. The planet recently witnessed its hottest recorded period, and the past five months have consecutively held the title of the warmest observed.
According to the United Nations, Brazil has warmed by 0.9 degrees in just the past few decades. Changes in land use, including the deforestation of the Amazon, are believed to accelerate this warming trend.
So, the next time you contemplate attending a concert or any outdoor event, it might be prudent to check the weather forecast or prepare to face the elements. Stay informed to avoid unforeseen consequences and ensure a safe experience amidst the elements.
