Dear Jim, In the “younger dryas” period, the surface heating was different in Northern and Southern Henispheres with interesting consequences. Worth looking at again.
Any way injecting in one hemisphere will spread to other hemisphere , albeit slowly, but obs suggest faster than low resolution models indicate as don’t include small scale and mixing processes such as gravity waves et al . regards Alan T --- Alan Gadian, UK. Tel: +44 / 0 775 451 9009 T --- > On 12 Jan 2022, at 09:57, Haywood, James <[email protected]> wrote: > > > Hi All, > > I'm with Doug on this one. It would be pathological to inject solely into one > hemisphere. The original paper that looked at this (almost a decade ago, > Haywood et al., 2013 although there are plenty of papers before this > examining impacts of explosive volcanic eruptions - e.g. Luke Oman and Alan > Robock's work) showed that there are important detrimental impacts on the > ITCZ and associated rainfall should injections occur in one hemisphere. There > are a bunch of other papers that look at the energetics of preferential > heating one hemisphere in the HadGEM3 model (Haywood et al., and Hawcroft et > al papers), plus a whole host of others with other models that show that > perturbing the energy balance and hence the temperature in one hemisphere > will lead to shifts in the ITCZ. > > In many ways the "injections in one hemisphere only" simulations were > designed to head-off the idea that was mooted at the time that the current > fleet of civil aircraft could be used as an effective climate intervention > strategy. Having worked in this area for a while, I should stress that such > injection strategies are rather pathological. > > What Doug (and others) have done is to develop feedback controllers that > inject at multiple latitudes, and one of the primary objectives is to ensure > that the northern and southern hemisphere coolings are similar to prevent any > such detrimental impacts on the ITCZ and associated rainfall. > > Best Regards > > Jim > > > From: [email protected] <[email protected]> on > behalf of Cush Ngonzo Luwesi <[email protected]> > Sent: 12 January 2022 09:41 > To: [email protected] <[email protected]> > Cc: geoengineering <[email protected]>; Geoeng Info > <[email protected]>; Andrew Lockley <[email protected]> > Subject: Re: [geo] SG and Tropical Monsoons > > CAUTION: This email originated from outside of the organisation. Do not click > links or open attachments unless you recognise the sender and know the > content is safe. > > Dear Bala et Al. > These predictions are acurate and concur with many recent experiments > following the famous Robock (2008): ''Twenty reasons why Geoengineering is a > Bad idea''. Now We need strong policy measures to prevent Such catastrophies > at a global scale. > Kudos! > > Le dim. 9 janv. 2022 à 07:03, Govindasamy Bala <[email protected]> a écrit : > Dear All, > > In this paper that came out last week in Climate Dynamics, we looked at the > changes in mean precipitation in tropical monsoon regions for sulfate > injections at different latitudes. > > Key message: India could experience persistent droughts if aerosols are > injected at 15 or 30 deg N. The result is interpreted from planetary > energetics and interhemispheric asymmetry in energy balance. > > Many of you may be aware that Ben Kravitz, Doug, Simone and others have > worked on ideas such as controlled injections at several locations > simultaneously to avoid such catastrophes, but I am not sure we can really > have such precise control on the climate system.... > > -- > 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 > ------------------------------------------------------------------- > -- > 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/CAD7fhVk1OSANz7esABWgM%2BNFG9P%2BAo57Nuvecx27k9VF_Duvwg%40mail.gmail.com. > -- > 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/CAKo_7aoUOtkNrtFAFMV-TnUZDy%3DQu5EH1XgW0mmY56ABWufi%2BQ%40mail.gmail.com. > -- > 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/LOYP265MB21256EB125C91E53FFD7290799529%40LOYP265MB2125.GBRP265.PROD.OUTLOOK.COM. -- You received this message because you are subscribed to the Google Groups "geoengineering" group. 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