[fwlr]

The article mentions both rockets and volcanoes as causes of the increase, but carefully elides any mention of the exact numbers each contributes. I couldn’t easily find any concrete numbers on how much water vapor is involved in a typical rocket launch, but the 2022 Tonga underwater volcano eruption contributed an estimated 150 million tons of water vapor to the atmosphere, which is well beyond the scale of rocket launch contributions. So it’s almost all volcanic and only trivially aeronautic.

[CrazyStat]

According to a random website[1] a Falcon 9 launch uses about 312 tons of liquid oxygen. Assuming that all gets converted into water that’s about 350 tons of water. Wikipedia[2] says there were 223 orbital rocket launch attempts in 2023. Almost half of those were Falcon 9, and if we assume for simplicity that the rest average out to around the same amount of water per launch that would give about 78 thousand tons total.

So about three orders of magnitude less than the one eruption.

[1] https://spaceimpulse.com/2023/06/13/how-much-does-rocket-fue...

[2] https://en.wikipedia.org/wiki/2023_in_spaceflight

[Full_Clark]

Falcon 9 rockets burn RP-1, a hydrocarbon fuel, so the oxygen is being converted to CO2, and CO as well as H2O. [1]

Beyond that, I don't think the direct comparison of mass is definitive. Much of the rocket's fuel is expended at lower altitudes, and much of a volcano's ejecta return quickly to earth as ash or rain. It would be important to understand what percentage of a volcano's ejecta reaches the height of these clouds as well as what percentage of a rocket's exhaust is produced at that height.

Just to throw in some round figures:

noctilucent clouds are formed between 80 and 85 km altitude [2]

large volcanic eruption plumes top out somewhere between 31 and 45 km [3]

Falcon 9 launches stage at 80 km [4], meaning 23% of their propellant mass [5] is converted to exhaust at that altitude or higher.

So while I'm no expert on noctilucent cloud formation and happy to be given more info, the prima facia case seems to favor rocket launches seeding noctilucent clouds much more readily than volcanic eruptions.

[1] https://en.wikipedia.org/wiki/RP-1#Comparison_with_other_fue... [2] https://www.albany.edu/faculty/rgk/atm101/nlc.htm , though other sources give a wider range of 76-85 km. [3] https://volcano.oregonstate.edu/faq/how-high-can-explosive-e... [4] https://www.nasa.gov/wp-content/uploads/2018/07/spacex_nasa_... [5] https://en.wikipedia.org/wiki/Falcon_9#Design