Wildfires have exploded in the Los Angeles area since the evening of January 7 (local time) until now, causing at least six deaths, nearly 180,000 people being evacuated, and more than 9,000 structures damaged in the process. when the fire power is still struggling to extinguish the spreading fire, NBC News reported on January 10.
The main cause of the fires is believed to be the prolonged dry conditions in this area, combined with the strong winds of the Santa Ana wind storm with speeds of up to 160km/h, making the situation worse. Fires spread quickly, making firefighting difficult.
“We know that the vegetation was already very dry, combined with dry and gusty Santa Ana winds, which made the risk of wildfires very high,” said Luca Carmignani, an associate professor at the University of San Diego and former consultant. wildfires in southern California said. “So once the fire started, it was no surprise that it spread so quickly.”
Authorities predict that fires will continue to rage in the next few days, posing a major threat to this area.
Santa Ana winds – the agent that fanned the fire
According to USA Today, Santa Ana winds often appear in the fall and winter, pushing dry air from California’s inland deserts and the southwest toward the coast.
As high pressure systems move east to west over the Santa Ana Mountains in southern California, winds are forced down, compressed and causing temperatures to rise.
The high pressure area in the Great Basin (plateau east of the Sierra Nevada mountains) combined with the storm in northwest Mexico has created conditions for strong winds to appear in southern California since January 7, according to experts. AccuWeather meteorologist Gwen Fieweger.
The Santa Monica and San Gabriel Mountains also have canyons and valleys that can act as conduits for Santa Ana winds, strengthening winds and accelerating the spread of wildfires in the area. mountain.
In addition, scientist Janice Coen working at the National Center for Atmospheric Research in Boulder (Colorado) said these winds also dry grass and trees on mountain slopes and can carry fire embers far away. causing fires to spread faster.
Lack of rain, low humidity
In addition to the Santa Ana winds, California’s previous severe dry season also contributed to the rapid spread of fires.
According to the latest report of the US Drought Index, 83% of Los Angeles is experiencing drought. AccuWeather, a private American media company specializing in providing weather forecast services globally, also said that the region has recorded extremely low rainfall since
Many wet winters over the years in Los Angeles have helped trees grow, but the current drought has turned them into an abundant source of dry fuel, said Heather Zehr, a senior meteorologist with AccuWeather.
Extremely low humidity also dries out trees, making them a source of fuel for fires.
“It is the drastic change from very wet to extremely dry that creates extreme situations like the fires in California, and this can be influenced by climate change,” Ms Zehr said.
