Very interesting work. I wish it included the actual heights chosen to release aerosol (held constant, or varied with location? etc), the dispersion rates, and the granulation in cooling effect.
Gregory Benford On Tue, Jul 10, 2012 at 10:09 AM, Josh Horton <[email protected]>wrote: > Hi all, > > Here is an abstract and link for an interesting manuscript on aerosol > injections to combat regional heatwaves, in this case California. It > touches on both regional schemes and the sometimes blurry line between > geoengineering and weather modification. > > Josh Horton > [email protected] > http://geoengineeringpolitics.blogspot.com/ > > > http://www.atmos.ucla.edu/~qli/publications/Bernstein_2012_ACPD.pdf > > Could aerosol emissions be used for regional heat wave mitigation? > > Abstract. Geoengineering applications by injection of sulfate > aerosols into the stratosphere are under consideration as > a measure of last resort to counter global warming. Here > adaptation to a potential regional-scale application to offset > 5 the impacts of heat waves is critically examined. The effect > of regional-scale sulfate aerosol emission over California > in each of two days of the July 2006 heat wave using the > Weather Research Forecast model with fully coupled chemistry > is used to quantify potential reductions in surface tem10 > perature as a function of emission rates in the lower stratosphere. > Over the range considered, afternoon temperature > reductions scale almost linearly with emissions. Local meteorological > factors yield geographical differences in surface > air temperature sensitivity. For emission rates of approx15 > imately 30 g mô€€€2 sô€€€1 over the region, temperature decreases > of around 7 C result during the middle part of the > day over the Central Valley, one of the hardest hit by the > heatwave. Regions more ventilated with oceanic air such as > Los Angeles have slightly smaller reductions. The length > 20 of the hottest part of the day is also reduced. Advection effects > on the aerosol cloud must be more carefully forecast for > smaller emission regions. Verification of the impacts could > be done via measurements of differences in reflected and surface > downward shortwave. Such regional geoengineering ap25 > plications with specific near-term target effects but smaller > cost and side effects could potentially provide a means of > testing larger scale applications. However, design trade-offs > differ from global applications and the size of the required > emissions and the necessity of emission close to the target > 30 region raise substantial concerns. The evaluation of this regional > scale application is thus consistent with global model > evaluations emphasizing that mitigation via reduction of fossil > fuels remains preferable to considering geoengineering > with sulfate aerosols. > > -- > You received this message because you are subscribed to the Google Groups > "geoengineering" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/geoengineering?hl=en. > > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
