Dear Stephen, I would not put much faith in this highly idealized model, unless it could be shown to actually simulate past monsoon variations. It is a nice intellectual exercise, but ignores many of the important processes of the climate system.
Alan Alan Robock, Professor II Director, Meteorology Undergraduate Program Associate Director, Center for Environmental Prediction Department of Environmental Sciences Phone: +1-732-932-9800 x6222 Rutgers University Fax: +1-732-932-8644 14 College Farm Road E-mail: rob...@envsci.rutgers.edu New Brunswick, NJ 08901-8551 USA http://envsci.rutgers.edu/~robock Stephen Salter wrote: > Hi All > > The attached paper by Zickfeld et al shows, in figure 2, what might > happen to the Indian Monsoon if we do nothing. Cooling the sea > relative to the land should move things in the opposite direction. > > Stephen > > Emeritus Professor of Engineering Design > School of Engineering and Electronics > University of Edinburgh > Mayfield Road > Edinburgh EH9 3JL > Scotland > tel +44 131 650 5704 > fax +44 131 650 5702 > Mobile 07795 203 195 > s.sal...@ed.ac.uk > http://www.see.ed.ac.uk/~shs > > > Alan Robock wrote: >> Dear Ken, >> >> I agree. We need several models to do the same experiment so we can >> see how robust the ModelE results are. That is why we have proposed >> to the IPCC modeling groups to all do the same experiments so we can >> compare results. Nevertheless, observations after large volcanic >> eruptions, including 1783 Laki and 1991 Pinatubo, show exactly the >> same precip reductions as our calculations. >> >> Even if precip in the summer monsoon region goes down, how important >> is it for food production? It will be countered by increased CO2 and >> increased diffuse solar radiation, both of which should make plants >> grow more. We need people studying impacts of climate change on >> agriculture to take our scenarios and analyze them. >> >> Alan >> >> Alan Robock, Professor II >> Director, Meteorology Undergraduate Program >> Associate Director, Center for Environmental Prediction >> Department of Environmental Sciences Phone: +1-732-932-9800 x6222 >> Rutgers University Fax: +1-732-932-8644 >> 14 College Farm Road E-mail: rob...@envsci.rutgers.edu >> New Brunswick, NJ 08901-8551 USA http://envsci.rutgers.edu/~robock >> >> >> >> Ken Caldeira wrote: >> >>> A few questions re claims about monsoons: >>> >>> 1. How well is the monsoon represented in the model's base state? Is >>> this a model whose predictions about the monsoon are to be trusted? >>> >>> 2. Since the believability of climate model results for any small >>> region based on one model simulation is low, for some reasonably >>> defined global metrics (e.g., rms error in temperature and precip, >>> averaged over land surface, cf. Caldeira and Wood 2008) is the >>> amount of mean climate change reduced by reasonable aerosol forcing? >>> (I conjecture yes.) >>> >>> Alan is interpreting as significant his little brown blotches in the >>> right side of Fig 7 in a model with 4 x 5 degree resolution (see >>> attachment). >>> >>> How does the GISS ModelE do in the monsoon region? If you look at >>> Fig 9 of Jiandong et al (attached), at least in cloud radiative >>> forcing, GISS ModelE is one of the worst IPCC AR4 models in the >>> monsoon region. >>> >>> So, while Alan may ultimately be proven right, it is a little >>> premature to be implying that we know based on Alan's simulations >>> how these aerosol schemes will affect the Indian monsoon. >>> >>> If you look at Caldeira and Wood (2008), we find that idealized >>> Arctic solar reduction plus CO2, on average precipitation is >>> increased relative to the 1xCO2 world. >>> >>> >>> ___________________________________________________ >>> Ken Caldeira >>> >>> Carnegie Institution Dept of Global Ecology >>> 260 Panama Street, Stanford, CA 94305 USA >>> >>> kcalde...@ciw.edu <mailto:kcalde...@ciw.edu>; kcalde...@stanford.edu >>> <mailto:kcalde...@stanford.edu> >>> http://dge.stanford.edu/DGE/CIWDGE/labs/caldeiralab >>> +1 650 704 7212; fax: +1 650 462 5968 >>> >>> >>> >> >> >> >> >> > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to geoengineering@googlegroups.com To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en -~----------~----~----~----~------~----~------~--~---
