2009/08/18

Icecore data CO2 CH4 Dust Temperature

I recently posted this on CA
http://www.climateaudit.org/?p=4804#comment-329759

The plots are from EPICA data, mainly not VOSTOK
The time scales are reversed (years before present)
The plots show temperature rise pretty much co-incident with CO2 rise. (samples are often too widly separated to safely say which came first!

————————
Does temperature precede GHG change?
Some plots
CO2 in most cases rises at the same time as temperature. CH4 seems to terminate the warm period in many cases. Data is from EPICA core as this is more detailed than vostok. BUT core dates can still be spaced at over 2k years per sample in some periods. N2O and O3 have not been plotted.
Where is the data that shows temperature rise precedes CO2?
0 to 40,000 years. GISP2 and EPICA temperatures plotted on this graph. Co2 steady rise is simultaneous with temperature @17500ybp
note that only greenland gisp2 temperature shows a definite younger dryas – the antarctic EPICA data shows a flattening only.The EPICA CH4 data shows a misplaced drop around the younger dryas. Note the dust levels during the low temperature portion.

40k to 100k years Note the dust levels are non zero during this period and high during the low temperature portion.

100k to 200k years Co2 rises simulaneously with temperature @136kybp. Note the dust levels are high during the low temperature portion. CH4 termination of warm period

180k to 260k years Co2 rises simulaneously with temperature @252kybp. the 220kybp is less defined. Note the dust levels are high during the low temperature portion. CH4 and CO2 termination of warm periods
280k to 360k years Co2 rises simulaneously with temperature @341kybp. Note the dust levels are high during the low temperature portion. CH4 termination of warm periods

360k to 460k years Co2 rises simulaneously with temperature @432kybp. Note the dust levels are high during the low temperature portion. CH4 termination of warm period


460k to 560k years Co2 rises simulaneously with temperature @532kybp. Note the dust levels are high during the low temperature portion. CH4 termination of warm period


560k to 650k years Co2 rises simulaneously with temperature @629.5kybp. Note the dust levels are high during the low temperature portion. CO2,CH4 termination of warm period


650k to 760k years Co2 rises simulaneously with temperature @740.5kybp. Note the dust levels are high during the low temperature portion. CO2,CH4 termination of warm period @694kybp. Note dip at 722kybp has no CH4/Co2 driving. It is possible that dust level rises at this time but granularity of dust data is not sufficiently small to line up.


750k to 800k years Co2 rises simulaneously with temperature @796kybp. Note the dust levels are high during the low temperature portion. CO2 termination of warm period

http://img21.imageshack.us/img21/3479/iceage750800kqf1.jpg

Methane data is from:

Loulergue, L., et al.. 2008.
EPICA Dome C Ice Core 800KYr Methane Data.
IGBP PAGES/World Data Center for Paleoclimatology
Data Contribution Series # 2008-054.
NOAA/NCDC Paleoclimatology Program, Boulder CO, USA.

Age scale is gas age

CO2 data is from
0-22 kyr BP: Dome C (Monnin et al. 2001) measured at University of Bern
22-393 kyr BP: Vostok (Petit et al. 1999; Pepin et al. 2001; Raynaud et al. 2005) measured at LGGE in Grenoble
393-416 kyr BP: Dome C (Siegenthaler et al. 2005) measured at LGGE in Grenoble
416-664 kyr BP: Dome C (Siegenthaler et al. 2005) measured at University of Bern
664-800 kyr BP: Dome C (Luethi et al. (sub)) measured at University of Bern

Age scale is gas age

I assume the gas age takes into account the delay in trapping?

The age used is EDC3 and a comparison between dome fuji and vostok is here
The EDC3 chronology for the EPICA Dome C ice core
http://www.clim-past.net/3/485/2007/cp-3-485-2007.pdf

gas to ice age 0-41k
http://www.clim-past.net/3/527/2007/cp-3-527-2007.pdf
“Although the exact causes of the 1arge
overestimate remain unknown, our work implies that the suggested
lag of CO2 on Antarctic temperature at the start of the
last deglaciation has probably been overestimated.”

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