This is an old revision of the document!
Go back to the main core experiment design page.
Go back to the main working group page.
Please note, this page is a work in progress and is not ready for discussion yet.
Please use the Discussion section below to specifically comment on the choice of greenhouse gases for the core experiment.
The composite record (EPICA Dome C, Vostok and Taylor Dome) from Lüthi et al. (2008)[1] provides CO2 data spanning 800 ka to present.
The data will be provided on the timescale of Veres et al. (2013)[2]
Comparison of CO2 records and the PMIP3 LGM 1)
In particular, note how the new AICC2012[2] age model affects the timing of the record and the 'LGM' CO2 value; now 188 ppm compared to 185 ppm in PMIP3. There are also differences in timing with the Marcott et al. (2014) record.
We are proposing to use the composite record of Lüthi et al. (2008)[1].
The EPICA Dome C record from Loulergue et al. (2008)[3] provides CH4 data also spanning 800 ka to present.
The data will be provided on the timescale of Veres et al. (2013)[2]
EPICA Dome C and the PMIP3 LGM 2)
Work in progress!
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.]
[ PMIP3 Wiki Home ] - [ Help! ] - [ Wiki syntax ]
Discussion on core experiment greenhouse gases
I think it makes sense to not use the Marcott data - they are offset from other Antarctic ice core values by about 4 ppm, consistently. The cause for this is still unresolved. Given that it wouldn't be easily spliced into a longer record, and the fact it is only between 23-9 ka, it is probably best to stick with the Luthi et al record.
For the N2O I agree that the 200 ppb looks representative of the LGM state and should be used.
I agree that 185 ppm CO2 and 350 ppb CH4 are underestimates on the new timescales. I think the record values at 21 ka look more representative of the LGM state.