If the effect is unavoidably year round, what's the sign on the sea ice net effect? Thus may be different to temp.
A On Sep 11, 2012 10:03 AM, "Stephen Salter" <[email protected]> wrote: > Hi All > > Six out of the eight models in the Driscoll et al paper show near > surface-warming in Arctic winters following volcanic eruptions. This is in > line with figure 2a the Jones Hayward Boucher Robock 2010 paper in > Atmospheric Chemistry and Physics. The obvious mechanisms are blanketing of > outgoing radiation and side-scatter of high solar rays that might have > missed the polar regions. Given the concerns about the loss of Arctic ice > and increased methane release we will have to be very careful not to let > any geo-engineering sulphur that we inject at low latitudes reach the > Arctic in winter. > > Stephen > > On 10/09/2012 16:52, Simon Driscoll wrote: > > Dear all, > > the published version (no longer PiP) is now available here: > > http://www.agu.org/pubs/crossref/2012/2012JD017607.shtml > > Warm regards, > > Simon > > ________________________________________________ > > Simon Driscoll > Atmospheric, Oceanic and Planetary Physics > Department of Physics > University of Oxford > > Office: 01865 272930 > Mobile: 07935314940 > > http://www2.physics.ox.ac.uk/contacts/people/driscoll > http://www.geoengineering.ox.ac.uk/people/who-are-we/simon-driscoll/ > ------------------------------ > *From:* [email protected] [[email protected]] > on behalf of Andrew Lockley [[email protected]] > *Sent:* 14 August 2012 02:06 > *To:* geoengineering > *Subject:* [geo] Coupled Model Intercomparison Project 5 (CMIP5) > simulations of climate following volcanic eruptions > > http://www.agu.org/pubs/crossref/pip/2012JD017607.shtml > > The ability of the climate models submitted to the Coupled Model > Intercomparison Project 5 (CMIP5) database to simulate the Northern > Hemisphere winter climate following a large tropical volcanic eruption is > assessed. When sulfate aerosols are produced by volcanic injections into > the tropical stratosphere and spread by the stratospheric circulation, it > not only causes globally averaged tropospheric cooling but also a localized > heating in the lower stratosphere, which can cause major dynamical > feedbacks. Observations show a lower stratospheric and surface response > during the following one or two Northern Hemisphere (NH) winters, that > resembles the positive phase of the North Atlantic Oscillation (NAO). > Simulations from 13 CMIP5 models that represent tropical eruptions in the > 19th and 20th century are examined, focusing on the large-scale regional > impacts associated with the large-scale circulation during the NH winter > season. The models generally fail to capture the NH dynamical response > following eruptions. They do not sufficiently simulate the observed > post-volcanic strengthened NH polar vortex, positive NAO, or NH Eurasian > warming pattern, and they tend to overestimate the cooling in the tropical > troposphere. The findings are confirmed by a superposed epoch analysis of > the NAO index for each model. The study confirms previous similar > evaluations and raises concern for the ability of current climate models to > simulate the response of a major mode of global circulation variability to > external forcings. This is also of concern for the accuracy of > geoengineering modeling studies that assess the atmospheric response to > stratosphere-injected particles.Received 13 February 2012; accepted 24 July > 2012. > -- > 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. > > > > -- > Emeritus Professor of Engineering Design School of Engineering University > of Edinburgh Mayfield Road Edinburgh EH9 3JL Scotland [email protected] +44 > (0)131 650 5704 Cell 07795 203 195 WWW.see.ed.ac.uk/~shs > > The University of Edinburgh is a charitable body, registered in > Scotland, with registration number SC005336. > > -- > 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.
