| Both sides previous revisionPrevious revisionNext revision | Previous revision |
| pmip3:wg:degla:bc:ghg [2015/03/02 11:22] – ruza | pmip3:wg:degla:bc:ghg [2025/05/15 17:51] (current) – jypeter |
|---|
| |
| /* Uncomment the following ~~DISCUSSION~~ line if you want to | /* Uncomment the following ~~DISCUSSION~~ line if you want to |
| allow users (including users who have NO write access to the page) to discuss | allow users (including users who have NO write access to the page) to discuss |
| More info here: http://wiki.splitbrain.org/plugin:discussion */ | More info here: http://wiki.splitbrain.org/plugin:discussion */ |
| | |
| ~~DISCUSSION|Discussion on core experiment greenhouse gases~~ | ~~DISCUSSION:closed|Discussion on core experiment greenhouse gases~~ |
| |
| ====== Last Deglaciation Greenhouse Gases ====== | ====== Last Deglaciation Greenhouse Gases ====== |
| The data will be provided on the AICC2012 timescale of [[http://www.clim-past.net/9/1733/2013/cp-9-1733-2013.html | Veres et al. (2013)]]<sup>[2]</sup>. \\ | The data will be provided on the AICC2012 timescale of [[http://www.clim-past.net/9/1733/2013/cp-9-1733-2013.html | Veres et al. (2013)]]<sup>[2]</sup>. \\ |
| \\ | \\ |
| **EPICA Dome C and the PMIP3 LGM** ((Plot produced by Lauren Gregoire, Feb 2015)) \\ | **EPICA Dome C and the PMIP3 LGM** ((Plot produced by Lauren Gregoire, April 2015)) \\ |
| {{ http://homepages.see.leeds.ac.uk/~earri/pmip_deglac/CH4.png? | EPICA Dome C CH4 }} \\ | {{ :pmip3:wg:degla:bc:ch4.png | EPICA Dome C CH4 }} \\ |
| Also note how the new AICC2012<sup>[2]</sup> age model affects the 'LGM' (21 ka; vertical dashed line) CH<sub>4</sub> value.\\ | Also note how the new AICC2012<sup>[2]</sup> age model affects the 'LGM' (21 ka; vertical dashed line) CH<sub>4</sub> value.\\ |
| |
| |
| ---- | ---- |
| |
| ===== Nitrous Oxide ===== | ===== Nitrous Oxide ===== |
| |
| |
| 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>.** \\ \\ |
| |
| ---- | ---- |
