The world’s rarest clouds appear over the San Francisco Bay Area

Noctilucent clouds — the world’s rarest clouds — appeared over San Francisco Bay in the early hours of Friday, just days after another SpaceX rocket launch.

Rain Hayes, a local photographer, saw the clouds sailing over Oakland’s Lake Merritt around 6:30 a.m. two days ago, before later posting images of the rare sighting to social media.

“Strange bright cloud over Lake Meritt this morning at the end of astronomical twilight,” she wrote, while notifying the National Weather Service’s regional office.

“Great capture of what appears to be a noctilucent cloud over the SF Bay Area this morning!” said UCLA climate scientist Daniel Swain in response to Hayes’ photo.

San Francisco Bay Area resident Rain Hayes announced Friday, April 16

Some scientists believe the increase in noctilucent clouds could be due to excess water vapor in the atmosphere from rocket launches. A launch was organized by Space X on Friday for the launch of a Falcon 9 rocket into space

UCLA climate scientist Daniel Swain called noctilucent clouds “very rare” and said they formed in the atmosphere about 50 miles up in the sky

“Such clouds are very rare at this latitude and even in winter and are the highest and driest clouds on earth, forming in the mesosphere at about 50 miles (!) altitude. Wow!’

The National Weather Service finally confirmed that noctilucent clouds had been present in the Bay Area before sunrise and that their passage was somewhat unusual.

Noctilucent clouds are usually only found at the extreme ends of the earth: the north and south poles. In the US, they are typically found on the West Coast and only in the Pacific Northwest.

Also known as polar mesospheric clouds, noctilucent clouds form between 47 and 53 miles above Earth’s surface (76 to 85 km), according to NASA.

Here, atmospheric circulation pushes air up, which then expands and cools.

Water vapor is then trapped in the clouds, freezing into ice crystals and forming meteorite dust.

Noctilucent clouds, or noctilucent clouds, typically form in late spring and early summer as the lower atmosphere warms. Pictured: Noctilucent clouds in Sweden in 2020

Noctilucent “noctilucent” clouds over Lancashire, UK in 2019. Sightings of this particular type of cloud have increased over the last decade, according to scientists

The clouds are also littered with debris from disintegrating meteors, giving them a “shocking” blue hue as they reflect sunlight. They typically form in late spring and early summer as the lower atmosphere warms.

Noctilucent clouds can even be seen from space, as astronauts from the International Space Station have previously shared images of the phenomenon.

In July, DailyMail.com reported sightings in certain parts of the US, Canada and Europe over a single weekend.

There is a belief that climate change is also contributing to their development and even that they are being seen at latitudes never seen before.

In 2019, for example, they were seen as far away as Joshua Tree, California, suggesting that with more greenhouse gases in the atmosphere, more water vapor is available for the glowing clouds to form.

Cora Randall, a professor at the University of Colorado Boulder, told the Washington Post that the increase in clouds could be due to excess water vapor in the atmosphere from rocket launches.

Noctilucent clouds can even be seen from space, but usually only form at the North or South Pole

A SpaceX Falcon 9 rocket lifts off from Cape Canaveral Space Force Station in Florida on Friday, December. On board were two O3B mPOWER communications satellites for SES Luxembourg

On Friday, a Space X Falcon 9 rocket launched the SWOT water observation satellite for NASA from California’s Vandenberg Space Force Base.

On Saturday, Space X launched another Falcon 9 rocket for the 15th time in a calendar year.

Another study suggests that the appearance of noctilucent clouds varies from year to year and even decade to decade, but that overall they have become “significantly” more visible.

Meanwhile, noctilucent clouds were first described in the mid-19th century after the Krakatoa erupted.

Volcanic ash spread through the atmosphere, making for vivid sunsets around the world and provoking the first known observations by NLCs.

At first people thought they were a side effect of the volcano, but long after Krakatoa’s ash settled, the thin, glowing clouds lingered.