What is going on
Over the past few days, high-altitude clouds have formed at the fastest rate since 2007.
Why it matters
Rocket exhaust may be the cause, but climate change is also known to make clouds more visible.
Nightly Luminous Clouds are the rarest and tallest type of cloud on Earth, and recently scientists have recorded more of them than at any time in the past 15 years.
They can look a bit like an impressionist painting of ocean waves, but with the evening sky as the canvas and real clouds as the paint. Nighttime clouds form high in the sky during the summer months when water molecules freeze around dust particles in the atmosphere, creating ethereal and artistic landscapes high above the land that tend to ripple and ripple as if reflecting a troubled sea somewhere.
Most nocturnal (the name literally means “nightly shining”) clouds form in the mesosphere, about 50 to 85 km above us, where you might assume that there is probably very little dust floating around so that water vapor can condense and freeze in the vicinity. Most of the material that causes these clouds comes from the smoke from meteors which burn as they blast through the upper atmosphere.
Easily one of the most vivid displays of nightly luminescent clouds we’ve seen in years here at NWS Seattle. There is really nothing else like them. We managed to capture the Pleiades star cluster and its nocturnal animals in one of the photos below.
What a way to start July!#wawx pic.twitter.com/oarVsuPU9q
— NWS Seattle (@NWSSeattle) July 1, 2022
But something else could also facilitate the recent dramatic rise of these clouds.
NASA has a spacecraft called AIM (for “aeronomy of ice in the mesosphere”) that helps study all the fascinating things that happen in the upper deck of our skies.
Cora Randall, a scientist and professor who works at the University of Colorado, Boulder, works with AIM data and was one of the first to verify that NLCs are way up.
“Over the past few days we saw a huge spike in the clouds,” she told Spaceweather.com last week.
In late June, there was a spike in the frequency of nighttime clouds that far surpassed previous peaks, going all the way back to 2007. One possible cause is the significant increase in rocket launches, led by SpaceX and others.
“We speculate that the spike may be due to additional water vapor being transported to higher latitudes by rocket launches,” Randall added.
According to astronomer Tony Phillips, it would take about 10 days for the water vapor that many rocket engines repel as exhaust fumes to drift to the mesophere. This means that the late June NLC peak Randall reports could be linked to a June 19 SpaceX launch that will also put on a show at lower altitudes immediately after blowing off.
Randall cautions that much more analysis needs to be done to confirm whether SpaceX actually plays a role in creating more rare clouds.
SpaceX did not immediately respond to a request for comment.
This animation shows the NASA AIM spacecraft’s view of the beginning of the Arctic night cloud season in 2020.
NASA/HU/VT/CU-LASP/AIM/Joy Ng
Research has also shown that nighttime clouds are sensitive to climate changeand their increased visibility may also be a byproduct of our warming planet.
Your best chance of spotting them for yourself is when conditions are clear, dry and summery. In the Northern Hemisphere, July is the peak of the NLC season. Go outside about 30 minutes after sunset and look west for those ethereal brushstrokes of ice in the sky. The higher your latitude, the more likely you are to see something and the longer these clouds last well into the night.
If you have great photos share them with me Twitter @EricCMack†
#mesmerizing #clouds #years #high #SpaceX #reason