Yeah, thanks for highlighting this. I started writing about it but realised I was out of my depth (even further out of my depth than for the rest of the post!) so I scrapped it.
Thanks for clarifying with Robert Rohde!
I reached roughly the conclusion you did. When water vapour is injected into the troposphere (the lowest level of the atmosphere) it is quickly rained out, as you point out. However, the power of the Hunga-Tonga explosion meant that the water vapour was injected much higher, into the stratosphere (what the diagram calls the ‘upper atmosphere’). For some reason, water vapour in the stratosphere doesn’t move back down and get rained out as easily so it sits there. Which is why ‘upper atmosphere’ water vapour levels are still elevated almost two years after the explosion.
Yeah, thanks for highlighting this. I started writing about it but realised I was out of my depth (even further out of my depth than for the rest of the post!) so I scrapped it.
Thanks for clarifying with Robert Rohde!
I reached roughly the conclusion you did. When water vapour is injected into the troposphere (the lowest level of the atmosphere) it is quickly rained out, as you point out. However, the power of the Hunga-Tonga explosion meant that the water vapour was injected much higher, into the stratosphere (what the diagram calls the ‘upper atmosphere’). For some reason, water vapour in the stratosphere doesn’t move back down and get rained out as easily so it sits there. Which is why ‘upper atmosphere’ water vapour levels are still elevated almost two years after the explosion.