Hi Stan + others.
Around one year after my post on the issue, another study was flagged to me: “Latent Heating Is Required for Firestorm Plumes to Reach the Stratosphere” (https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2022JD036667). The study raises another very important firestorm dynamic, that a dry firestorm plume has significantly less lofting versus a wet one due to the latent heat released as water moves from vapor to liquid—which is the primary process for generating large lofting storm cells. However, if significant moisture can be assumed in the plume (and this seems likely due to the conditions at its inception) lofting is therefore much higher and a nuclear winter more likely.
The Los Alamos analysis only assesses a dry plume—and this may be why they found so little risk of a nuclear winter—and in the words of the authors: “Our findings indicate that dry simulations should not be used to investigate firestorm plume lofting and cast doubt on the applicability of past research (e.g., Reisner et al., 2018) that neglected latent heating”.
This has pushed me further towards being concerned about nuclear winter as an issue, and should also be considered in the context of other analysis that relies upon the Reisner et al studies originating at Los Alamos (at least until they can add these dynamics to their models). I think this might have relevance for your assessments, and the article here in general.
Dear Tedd,
Thanks for the comment and engagement, but I’m not sure the sources you list demonstrate that there was a firestorm at Nagasaki (which, if true, would raise the concern about nuclear winter at the margin).
Certainly, there was a huge fire at Nagasaki—much like large scale forest fires and other mass conflagrations—and your sources support that fact. However, such fires do not seem to inject stratospheric soot in the absence of a firestorm—it was predicted for both Iraqi oil well fires and conventional mass forest fires where ultimately a stratospheric soot injection/climate shock did not manifest.
Instead, it really seems to need a firestorm. This is not just a big fire that kills many people and burns many things—as a nuclear weapon is certain to do over a city. A rolling fire may burn the same area or event kill as many people, but it will not inject the same soot, it is the self reinforcing firestorm “cell” that is the key here.
Claiming Nagasaki was not a firestorm is an observation about the nature of the fire that formed, and the resulting soot lofting (notice, the iconic photo of Hiroshima’s soot “anvil” was not matched to my knowledge by a similar photo from Nagasaki—as there wasn’t a firestorm to loft it, just a massive conflagration). I carried out no battle damage assessment at Nagasaki—and I have no basis to do so, I’m simply going on what was reported—if you have a source that explicitly reports a firestorm cell forming above Nagasaki I would be very interested to read it. However, the academic consensus seems to be that there was not one—and from what I understand planners were even disappointed by the fact, there doesn’t seem to be any form of coverup if that was your concern?
If you do think that Nagasaki resulted in a firestorm and soot lofting however, that would push concerns upwards for a climate shock in the event of a nuclear conflict—which I am certainly concerned about too.