Los Angeles County, California, is in a state of emergency due to six wildfires that have consumed more than 11,000 hectares, destroyed 2,000 buildings, displaced nearly 130,000 residents and caused the death of five people. Experts warn that the Santa Ana winds are intensifying the fire and making containment efforts difficult.
The Santa Ana winds are a meteorological phenomenon characteristic of California, United States, which occurs between 10 and 25 times a year during the coldest months. They last an average of one to seven days. They are distinguished by strong air currents that move from the mountains towards the southern coast of the region.
Jon Keeley, a research ecologist with the United States Geological Survey, explains that this atmospheric event “is generated when there are high pressures in the east, in the Great Basin, and low pressures off the coast. Air masses move from high to low pressure. “The more pronounced the pressure difference, the stronger the winds.”
These winds usually reach speeds of between 48 and 64 kilometers per hour (km/h), although in extreme cases they can register gusts of up to 160 km/h. As air moves, it loses moisture and heats up. The effect dries out the vegetation and makes it highly flammable, favoring the generation and rapid spread of fires.
Why do Santa Ana winds affect California so much?
Various studies have shown that autumn rains reduce the risk of fires associated with the Santa Ana winds. Despite this, Southern California is experiencing an exceptionally arid situation. Data from the Climate Prediction Center indicates that only 10% of the state was under some level of drought as of October of last year. However, records released last week show that more than 30% of the state is experiencing dry conditions. The southern zone reports below-average rainfall, with less than 6 millimeters of rain since early July.
Keeley says California is experiencing more destructive forest fires than in the past, a trend also seen globally. A recent study published in the journal Nature Ecology & Evolution reveals that the number and intensity of these events worldwide have doubled in the last two decades.
Scientists attribute these catastrophes to both natural factors and the influence of human activities. However, they agree that global warming is exacerbating the fires. The unprecedented increase in terrestrial temperatures is one of the clearest manifestations of climate change and one of the main causes of the intensification of these disasters.
Mike Flannigan, a professor at the University of Alberta, points out that extreme heat draws moisture out of vegetation more quickly, making it more flammable. “The drier fuels are a critical part of the fire, the drier the material, the easier it is to start a fire,” he states in a statement taken up by the network. cnn.
#Santa #Ana #winds #intensifying #fires #Los #Angeles
