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pmip3:wg:degla:bc:ghg [2015/04/09 09:03]
lauren [Methane]
pmip3:wg:degla:bc:ghg [2015/10/21 13:42] (current)
ruza
Line 64: Line 64:
  
 Please think about the following points and add any comments on these or any other aspects of the experiment design to the discussion section below: [Topics will be added here as they are raised below or by email.] Please think about the following points and add any comments on these or any other aspects of the experiment design to the discussion section below: [Topics will be added here as they are raised below or by email.]
-  * With the new AICC2012<​sup>​[2]</​sup>​ age model, the LGM values for CO<​sub>​2</​sub><​sup>​[1]</​sup>​ and CH<​sub>​4</​sub><​sup>​[4]</​sup>​ are inaccurate, as can be seen from the plots above. Do we need a new PMIP LGM definition for these greenhouse gases in accordance with the records? \\ \\ +  ​* **RESOLVED** With the new AICC2012<​sup>​[2]</​sup>​ age model, the LGM values for CO<​sub>​2</​sub><​sup>​[1]</​sup>​ and CH<​sub>​4</​sub><​sup>​[4]</​sup>​ are inaccurate, as can be seen from the plots above. Do we need a new PMIP LGM definition for these greenhouse gases in accordance with the records? ​**DECISION (Oct 2015): We have used the new, up to date CO<​sub>​2</​sub>​ (188 ppm) and CH<​sub>​4</​sub>​ (375 ppb) values for our LGM equilibrium-type 21 ka spinup. We do not know what the LGM group'​s decision will be.**\\ \\ 
-  * N<​sub>​2</​sub>​O<​sup>​[1]</​sup>​ values take a dive in the lead up to 21 ka. The PMIP3 value of 200 ppb looks fairly representative of the LGM state, even though this is a bit higher than the actual 21 ka value. We recommend that groups spin-up with 200 ppb N<​sub>​2</​sub>​O,​ and begin the transient simulation from 21 ka in the record (as shown in the plot above). ​ \\ \\ +  ​* **RESOLVED** N<​sub>​2</​sub>​O<​sup>​[1]</​sup>​ values take a dive in the lead up to 21 ka. The PMIP3 value of 200 ppb looks fairly representative of the LGM state, even though this is a bit higher than the actual 21 ka value. We recommend that groups spin-up with 200 ppb N<​sub>​2</​sub>​O,​ and begin the transient simulation from 21 ka in the record (as shown in the plot above). ​**DECISION (Oct 2015): We have stuck with the old, more representative N<​sub>​2</​sub>​O value of 200 ppb. However, the transient '​spinup'​ 26-21 ka and the transient run (21-9 ka) should use the chronologically accurate values, as plotted above. We do not know what the LGM group'​s decision will be.** \\ \\ 
-  * Should the core experiment use the [[http://​www.nature.com/​nature/​journal/​v514/​n7524/​full/​nature13799.html | Marcott et al. (2014)]]<​sup>​[3]</​sup>​ CO<​sub>​2</​sub>​ records? \\ For example, these newer data are higher resolution than [[http://​www.nature.com/​nature/​journal/​v453/​n7193/​full/​nature06949.html | Lüthi et al. (2008)]]<​sup>​[1]</​sup>,​ but are restricted to 23-9 ka. Therefore more consistency may be be gained from using the older [[http://​www.nature.com/​nature/​journal/​v453/​n7193/​full/​nature06949.html | Lüthi et al. (2008)]]<​sup>​[1]</​sup>​ CO<​sub>​2</​sub>​ records, if longer simulations are planned by groups. Also, CH<​sub>​4</​sub>​ and N<​sub>​2</​sub>​O data are not yet available in such high resolution. \\ \\+  ​* **RESOLVED** Should the core experiment use the [[http://​www.nature.com/​nature/​journal/​v514/​n7524/​full/​nature13799.html | Marcott et al. (2014)]]<​sup>​[3]</​sup>​ CO<​sub>​2</​sub>​ records? \\ For example, these newer data are higher resolution than [[http://​www.nature.com/​nature/​journal/​v453/​n7193/​full/​nature06949.html | Lüthi et al. (2008)]]<​sup>​[1]</​sup>,​ but are restricted to 23-9 ka. Therefore more consistency may be be gained from using the older [[http://​www.nature.com/​nature/​journal/​v453/​n7193/​full/​nature06949.html | Lüthi et al. (2008)]]<​sup>​[1]</​sup>​ CO<​sub>​2</​sub>​ records, if longer simulations are planned by groups. Also, CH<​sub>​4</​sub>​ and N<​sub>​2</​sub>​O data are not yet available in such high resolution. ​**DECISION (Oct 2015): We have chosen to use the older data from [[http://​www.nature.com/​nature/​journal/​v453/​n7193/​full/​nature06949.html | Lüthi et al. (2008)]]<​sup>​[1]</​sup>​.** ​\\ \\
  
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pmip3/wg/degla/bc/ghg.1428570213.txt.gz · Last modified: 2015/04/09 09:03 by lauren