Images taken from space show vast plumes of smoke billowing from the wildfires burning on the outskirts of Los Angeles, filling the air with particulate pollution.

The Line Fire in San Bernardino County threw out so much smoke and heat that it generated “fire clouds”—also known as pyrocumulus or flammagenitus—in the sky above it, which were snapped from space.

The smoke from this fire, as well as from the Bridge Fire and Airport Fire nearby, have wreaked havoc on the air quality between the eastern edge of L.A. and the Coachella Valley, sparking warnings for residents to stay indoors.

Pyrocumulus clouds are formed when extreme heat rises into the atmosphere, often from a wildfire or volcanic eruption. The intense heat causes the air near the ground to rise rapidly, eventually cooling and condensing into water droplets, forming a towering cumulus cloud.

In the case of wildfires or volcanic eruptions, pyrocumulus clouds often contain large amounts of ash, soot, and other particles that are lofted into the air along with the water vapor, giving the cloud a dark, dirty appearance.

These images of the fire clouds rising above the Line Fire were captured from space by the OLI (Operational Land Imager) on Landsat 8.

On Tuesday, the smoke from this fire and the others burning nearby caused “Moderate to Unhealthy” Air Quality Index (AQI) levels in Palm Springs and Indio.

“Windblown dust will add to the current smoke pollution and is expected to cause Air Quality Index (AQI) values to reach Unhealthy for Sensitive Groups or worse in the Coachella Valley and Banning pass between Tuesday evening and Thursday morning,” the South Coast AQMD said in a statement.

The South Coast AQMD warns residents to “limit your exposure by remaining indoors with windows and doors closed or seeking alternate shelter,” avoid physical activity and use AC or air purifiers.

The AQI is calculated based on several key air pollutants regulated by health standards, including PM10 and PM2.5 particulate matter, ozone, carbon monoxide, sulfur dioxide, and nitrogen dioxide. At “Unhealthy for Sensitive Groups” levels, members of sensitive groups —like children, the elderly, and people with respiratory or heart conditions—may experience health effects.

The Line Fire, which started near Highland on September 5, has now burned 34,659 acres as of about 7 a.m. local time on September 11 and is only about 14 percent contained. Over 65,600 structures are at risk from the blaze, and several neighborhoods have Evacuation Orders and Evacuation Warnings in place. The smoke from other nearby fires has actually helped slow the spread of the blaze.

“In the overnight hours of the Line Fire Wednesday, fire activity was moderated due to smoke shading and cooler weather. However, the fire grew on the north and east sides due to slope and vegetation driven runs,” Cal Fire said in a report this morning.

“Today elevated winds and continued dry conditions will allow the fire to grow. Smoke from fires across the region will help moderate fire activity unless the skies clear and the smoke thins. That would allow for more slope and vegetation aligned runs. There are 3,179 personnel assigned to the fire. Limited resource availability continues to hamper control efforts.”

To the west of the Line Fire, just north of Glendora, is the Bridge Fire. Burning across both Los Angeles and San Bernardino Counties, this blaze is 47,904 acres in area and 0 percent contained.

“Excessive heat and Red Flag Warning until Wednesday afternoon due to hot, dry, and unstable conditions with gusty onshore winds. Winds will shift to the west and northwest on Wednesday, which may impact higher elevation areas. Temperatures will remain high, however humidity will improve and increase slightly. Large vertical plume growth and visible smoke columns will be expected again for this fire,” an Inciweb update said.

To the south of both of these fires, near Trabuco Canyon, the Airport Fire has grown from 5,432 acres on Tuesday to 22,376 acres as of Wednesday morning. This fire is also 0 percent contained.

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