A dense fog blanketing California's Central Valley since Thanksgiving has led to online speculation about a mysterious and dangerous 'radiation fog.' However, scientists explain that the term refers to a common weather phenomenon, not nuclear radiation.
Known locally as 'tule fog,' named after a native marsh plant, this type of fog forms when moist ground cools rapidly at night, causing water vapor to condense. A rainy autumn and a late November high-pressure system have exacerbated conditions, creating a fog bank stretching up to 400 miles.
Residents have described the fog as eerie and unusually thick. David Mas Masumoto, a peach farmer in the San Joaquin Valley, told The New York Times he cannot recall such dense fog in 50 years. Some have reported soot-like particles on their vehicles, prompting health concerns.
Peter Weiss-Penzias, a fog researcher at UC Santa Cruz, explained to The Los Angeles Times that fog readily absorbs pollutants. The Central Valley, with its major highway and agricultural activity, suffers from poor air quality, meaning the particles could be a mix of various contaminants.
The fog is expected to thin as heavy rains move into the region later this week, disrupting the current weather pattern.
