A 400-mile blanket of fog lingered for weeks in California’s Central Valley. Scientists and meteorologists say the conditions are ripe for persistent cloud cover: an early rainy season, cold temperatures and a stable, stationary high-pressure system.
But take a trip through X, Instagram or TikTok, and you’ll see that not everyone is sanguine.
People report that this fog has a strange consistency and is full of black and white particles that don’t seem normal. They called it “mysterious” and emphasized the term “radiation” fog, which is the scientific description of such natural fog events — not an indication that they contain radioactive material.
X user with the handle Wall Street Apes posted a video of a man who said he was from Northern California drawing his finger near the fog on the grill of his truck. His finger is covered in white.
“What is this—right here?” The man said as the camera zoomed in on his finger. “There’s a fog that I can’t explain … Look everyone … you’re crazy … What’s going on? They’ve got asbestos in there.”
Another user, @wesleybrennan87, posted a photo of two planes crossing the sky during fog.
“For anyone following the thick Tule (Radiation) fog in the California Valley, it lifted for a while today, just to see if they were working properly over our heads…” posted a user.
Scientists confirm that there are objects in the fog. But what it is and where it comes from, they say, is disappointing.
The Central Valley is known for some of the worst air pollution in the country.
And “haze is very susceptible to pollutants,” says Peter Weiss-Penzias, a haze researcher at UC Santa Cruz.
Fog “droplets have a lot of surface area and are suspended in the air for a long time – days or weeks – so during that time the water droplets can absorb a lot of gases and particles, otherwise known as pollutants,” he said.
He said that although he has not done anything to analyze the fog in the Central Valley in this recent event, it is not difficult to imagine what is hidden in the droplets.
“It can be an alphabet soup of different things.” With all kinds of agriculture in this area, factories, cars, wood smoke, there are a lot of people competing, Weiss-Penzias said.
Reports that fog turns into gelatinous goo when left to settle aren’t surprising, he said, considering all the airborne organisms — mold particles, nutrients and algae — float around and can stick to water droplets like Velcro.
He said what is interesting is that although the main route of exposure for people to this substance is inhalation, the mist droplets are relatively large. That means that when you breathe them in, they won’t get too deep into the lungs – not like the particles we inhale during sunny, dry days. Those things can go down into the lung tissue.
The main concern is food, as the fog covers crops or open water sources, he said.
So make sure you wash your vegetables, and anything you leave out that you might end up doing later.
Dennis Baldocchi, a fog researcher at UC Berkeley, agreed with Weiss-Penzias’ assessment, saying that a storm system predicted to move in this weekend could clear up the fog and relieve the valley of its cold, dirty blanket.
But, if a high pressure system returns in the coming weeks, it won’t be surprising to see the region covered in fog again.
