A thick fog blanketing California's Central Valley since Thanksgiving has sparked online concerns about a harmful 'radiation fog,' but scientists say the term is misunderstood. The fog, known locally as 'tule fog,' forms when moist ground cools rapidly at night, causing water vapor to condense. The term 'radiation' refers to energy radiation, not nuclear radiation.
The fog has been exacerbated by a rainy autumn and winter, as well as a late November high-pressure system, creating a fog bank stretching up to 400 miles. Residents describe the fog as cold and eerie, with some reporting soot-like particles on their vehicles.
David Mas Masumoto, a peach farmer in the San Joaquin Valley, told The New York Times the fog feels like 'going into a dream stage where you can’t see anything around you.' He noted he hasn't seen such thick fog in 50 years.
Peter Weiss-Penzias, a fog researcher at UC Santa Cruz, explained to The Los Angeles Times that fog is highly susceptible to pollutants, which could explain the particles. The Central Valley is known for poor air quality due to traffic and agriculture. The fog is expected to thin as heavy rains arrive.
