cc: wg1-ar4-ch06@joss.ucar.edu date: Thu, 28 Jul 2005 01:17:13 +0200 from: Fortunat Joos subject: [Wg1-ar4-ch06] introduction 6.2.1 - 6.4.1 holocene solar. to: Jonathan Overpeck , Eystein Jansen Hi Peck and Eystein, here my general comment on the introduction and specific comments on section 6.2.1 and 6.4.1. 6.1 and 6.2.1: Well done! (1) Perhaps, words such as 'significant' and other value judgment terms could be used somewhat less. e.g. 'With proper care, current methodologies alloww more accurate age models' more accurate than what? We always hope that things are done with proper care. (2) The following sentence must in my opinion be deleted: 'but also note that new work reveals that cosmogeninc-isotope-derived estimates of solar forcing for the Holocene are not likely as well-constrained as commonly thought.' This is a very sweeping statement that is not backed up by the chapter text. It is also a very policy sensitive statement. We are either able to firmly support that or to drop it. I suspect that the paleo community would be divided about this. Scott Lehmann has just shown me a plot with a really nice correlatin between d18O in N-pachy in the Norht-Atlatnic and sunspots over the past 400 years. Yes, there appears to be a link. I also doubt that some of the existing work, e.g. Fleitman etc can be dismissed so easily. section 6.4.1: (3) I also think that the Holocene text on solar needs some readjustments. Linking the studies suggesting solar changes and those with NADW variations seems a somewhat improper comparison. The present text reads: 'Based on the correlation between changes in atmospheric concentrations of cosmogenic isotopes (10Be or 14C) and climate proxy records, some authors argue that solar activity may be the driver for an organised centennial to millennial scale variability (e.g., (Bond et al., 2001; Fleitmann et al., 2003) (Karlen, 1996) (Wang et al., 2005b), whereas others point to modes of variability driven by processes within the climate system, for instance related to the deep ocean circulation (Bianchi and McCave, 1999) (Duplessy et al., 2001) (Oppo et al., 2003) (Marchal et al., 2002).' I suggest to change it to something along the following line. "'Based on the correlation between changes in atmospheric concentrations of cosmogenic isotopes (10Be or 14C) and climate proxy records, many studies suggest that solar activity may be a driver for centennial to millennial scale variability (e.g., (Bond et al., 2001; Fleitmann et al., 2003) (Karlen, 1996) (Wang et al., 2005b). The importance of (forced or unforced) modes of variability within the climate system, for instance related to the deep ocean circulation has been pointed out (Bianchi and McCave, 1999) (Duplessy et al., 2001) (Oppo et al., 2003) (Marchal et al., 2002)." With best regards, Fortunat Quoting Fortunat Joos : > Hi Stefan, Peck and all, > > Here an update on the abrupt event figure and the figure caption. There were > some lost lines in the one send yesterday - please delete. I have now also > numbered some of the D/O events and the A1 to A4 events. > > The purpose of the figure is to demonstrate the asynchrounous evolution of NH > and SH temperatuere and the magnitude of the GHG changes during abrupt > events. > > Clearly, it would be great if the figure could be amended by other > information, > e.g. from the land or sediment records. We may also think about indicating > the > local Greenland temperatre change for the bigger events. > > Any ideas, suggestions, comments are welcomed. > > Peck: please include ERIC MONNIN as a Contributing author. > > Eric has synchronized the Taylor Dome and Dome C data on the GRIP time scale > and > helped me greatly to put toghether the records for the abrupt event and for > the > LGM-box figures. > > With best regards, > > Fortunat > > Quoting Fortunat Joos : > > > Hi, > > > > Here finally the abrupt event figure plus an update of the LGM-box figure. > > Will provide figure caption, section 6.6. text and shortened LGM-box > > tomorrow. > > > > With best regards, > > > > Fortunat > > > > -- > > e-mail: joos@climate.unibe.ch; > > > > Until November 23 > > National Centre for Atmospheric Research, Terrestrial Sciences, CGD > > 1850 Table Mesa Drive, Boulder, CO, 80305 > > ++1-303 497 13 44 (office) > > > > home address: > > 3655 Emerson Avenue, Boulder, CO, 80305 > > ++1-303 494 69 52 (home) > > > > After November 24 > > Climate and Environmental Physics > > Sidlerstr. 5, CH-3012 Bern > > Phone: ++41(0)31 631 44 61 Fax: ++41(0)31 631 87 42 > > Internet: http://www.climate.unibe.ch/~joos/ > > > > > > > -- > e-mail: joos@climate.unibe.ch; > > Until November 23 > National Centre for Atmospheric Research, Terrestrial Sciences, CGD > 1850 Table Mesa Drive, Boulder, CO, 80305 > ++1-303 497 13 44 (office) > > home address: > 3655 Emerson Avenue, Boulder, CO, 80305 > ++1-303 494 69 52 (home) > > After November 24 > Climate and Environmental Physics > Sidlerstr. 5, CH-3012 Bern > Phone: ++41(0)31 631 44 61 Fax: ++41(0)31 631 87 42 > Internet: http://www.climate.unibe.ch/~joos/ > > -- e-mail: joos@climate.unibe.ch; Until November 23 National Centre for Atmospheric Research, Terrestrial Sciences, CGD 1850 Table Mesa Drive, Boulder, CO, 80305 ++1-303 497 13 44 (office) home address: 3655 Emerson Avenue, Boulder, CO, 80305 ++1-303 494 69 52 (home) After November 24 Climate and Environmental Physics Sidlerstr. 5, CH-3012 Bern Phone: ++41(0)31 631 44 61 Fax: ++41(0)31 631 87 42 Internet: http://www.climate.unibe.ch/~joos/ _______________________________________________ Wg1-ar4-ch06 mailing list Wg1-ar4-ch06@joss.ucar.edu http://www.joss.ucar.edu/mailman/listinfo/wg1-ar4-ch06