The entire world’s climate is currently being dominated by one thing: The 2022 Hunga Tonga–Hunga Haʻapai volcanic eruption. In modern times it is only comparable to the 1883 eruption of Krakatoa.
That eruption blew so much ash into the stratosphere that sunsets around the world were brightly colored for four years. The ash blocked solar radiation so average temperature around the world also dropped.
However, Hunga Tonga was a giant *underwater* volcano. It blew water all the way through the stratosphere and into the mesosphere (29 to 62 miles). And while ash blocks sunlight coming towards Earth, water keeps radiation trapped on Earth. Water is the most important part of the “Greenhouse Effect”.
The mesosphere is generally very cold. Definitely cold enough to freeze water. So there is now a vast amount of ice crystals in the stratosphere and the mesosphere. And no idea how long they will stay there until they precipitate back to Earth or move out into space.
I agree with your evaluation. And the Stratosphere and Mesosphere normally have almost no water vapor.