My understanding is that current consensus is that adding black carbon to the stratosphere would be a bad idea, so the paper proposing using it for lofting is unlikely to be implemented.
But what if we used forest fires as a natural(ish) source of black carbon for lofting? Are there enough such fires that this could be a viable option for lifting sulfur to the stratosphere, without deliberately adding more? Andrew On Wed, 19 Oct 2022, 07:10 Govindasamy Bala, <[email protected]> wrote: > > Besides the effects on stratospheric circulation and chemistry, > stratospheric warming caused by sulfate aerosols reduces the effectiveness > of what we are trying to achieve. The main intent is to increase sunlight > reflection. Part of this cooling effect is offset by stratospheric warming. > In a 2019 ESD paper, we show this by prescribing volcanic aerosols at 16, > 19, and 22 km. In all these 3 cases, there is stratospheric warming. > However, in the case of 16km which is close to the troposphere, the > stratospheric warming leads to more water vapor in the stratosphere which > could further offset the originally intended cooling. > > https://doi.org/10.5194/esd-10-885-2019 > > Cheers, > Bala > > On Wed, Oct 19, 2022 at 8:52 AM 'Adrian Hindes' via geoengineering < > [email protected]> wrote: > >> I'm not an expert on atmospheric dynamics, but am aware of some relevant >> papers in that general direction. >> >> Gao et al. (2021) looked at "practical" SAI using solar powered lofting >> from black carbon particles, partly inspired by the dynamics seen from >> large bushfires: https://www.science.org/doi/10.1126/sciadv.abe3416 >> >> More broadly related, Christian et al. (2019) looked at the radiative >> forcing and stratospheric warming impacts of pyrocumulonimbus clouds: >> https://doi.org/10.1029/2019GL082360 >> Along the same lines, Peterson et al. (2021) looked specifically at the >> Black Summer bushfires in Australia from 2019-20: >> http://www.nature.com/articles/s41612-021-00192-9 >> >> Similar methods from those studies would presumably be applicable to >> studying SAI injection, and/or the potential dynamics between artificially >> injected sulphur (or other) aerosols with stratospheric warming events, >> pyroCb clouds and the like. I imagine there would be quite a lot of >> complexity with potentially compounding effects, maybe increasing aerosol >> lifetime, mixing and regional hydroclimatic changes, etc. >> >> Speaking of which, Simpson et al. (2019) specifically looked at the >> regional hydroclimatic effects of SAI, and how stratospheric heating plays >> into it: 10.1029/2019JD031093 <https://doi.org/10.1029/2019JD031093>. >> >> My understanding from reading that paper and others is stratospheric >> heating dynamics of SAI is one of those areas where there's still quite a >> lot of uncertainty, and an area of active research. Maybe other folks in >> the group here who have more experience with ESMs and atmospheric dynamics >> can comment further. I know the perspective paper by Ben Kravitz and >> Doug MacMartin <http://dx.doi.org/10.1038/s43017-019-0004-7> on >> uncertainty in solar geo research picked out stratospheric heating impacts >> on tropospheric and surface climate as one of the key outstanding >> uncertainties. >> >> On Wednesday, 19 October 2022 at 6:35:43 am UTC+11 [email protected] >> wrote: >> >>> Hi all, >>> Do people know of the impact of stratospheric warming that SRM causes on >>> the injection of other aerosols into the stratosphere, say from wildfire >>> events or volcanic eruptions? Like, how does a warm stratosphere effect how >>> these aerosols rise into the stratosphere and the dynamics of them within >>> the stratosphere >>> Best Wishes >>> Gideon >>> >> -- >> You received this message because you are subscribed to the Google Groups >> "geoengineering" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/geoengineering/7c0da4f8-f39e-41bb-90ba-ad2615ea8a68n%40googlegroups.com >> <https://groups.google.com/d/msgid/geoengineering/7c0da4f8-f39e-41bb-90ba-ad2615ea8a68n%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > > > -- > With Best Wishes, > > ------------------------------------------------------------------- > G. Bala > Professor > Center for Atmospheric and Oceanic Sciences > Indian Institute of Science > Bangalore - 560 012 > India > > Tel: +91 80 2293 3428; +91 80 2293 2505 > Fax: +91 80 2360 0865; +91 80 2293 3425 > Email: [email protected]; [email protected] > Google Scholar <https://scholar.google.com/citations?user=eurjQPwAAAAJ> > ------------------------------------------------------------------- > > -- > You received this message because you are subscribed to the Google Groups > "geoengineering" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/geoengineering/CAD7fhVn_DJ4my7aDit6GPU7OXzPMozsHoZeG0%2BKaO_ubwCovPg%40mail.gmail.com > <https://groups.google.com/d/msgid/geoengineering/CAD7fhVn_DJ4my7aDit6GPU7OXzPMozsHoZeG0%2BKaO_ubwCovPg%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. 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