noaa-icecore-13398
NGRIP and EDML Ice Core 32-11KYrBP Methane Data
Baumgartner, M.; Schilt, A.; Eicher, O.; Schmitt, J.; Schwander, J.; Spahni, R.; Fischer, H.; Stocker, T.F.
NGRIP and EDML Ice Core 32-11KYrBP Methane Data
2012-10-17
NCDC-Paleoclimatology
ONLINE Files
Pending
https://www.ncdc.noaa.gov/paleo/study/13398
Investigator
M.
Baumgartner
Investigator
A.
Schilt
Investigator
O.
Eicher
Investigator
J.
Schmitt
Investigator
J.
Schwander
Investigator
R.
Spahni
Investigator
H.
Fischer
Investigator
T.F.
Stocker
earth science
paleoclimate
ice cores
notes,null,null,null,null,ice cores,null,null,C,null
earth science
paleoclimate
climate forcing|ice cores
methane,bulk atmosphere,one standard deviation,parts per billion,null,climate forcing|ice cores,null,null,N,null
earth science
paleoclimate
ice cores
depth,null,null,meter,null,ice cores,null,null,N,null
earth science
paleoclimate
ice cores
gas age,null,null,calendar year before present,null,ice cores,null,null,N,null
earth science
paleoclimate
climate forcing|ice cores
methane,bulk atmosphere,null,parts per billion,null,climate forcing|ice cores,null,null,N,null
earth science
paleoclimate
ice core
atmospheric gas
geoscientificInformation
Last Glacial Maximum
31924 cal yr BP
11067 cal yr BP
Complete
-75
75.1
-42.33
.07
2892
2917
Continent
Antarctica
EPICA Dronning Maud Land>LATITUDE -75>LONGITUDE .07
Continent
North America
Greenland
NGRIP>LATITUDE 75.1>LONGITUDE -42.33
None
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English
DOC/NOAA/NESDIS/NCEI
National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
https://www.ncdc.noaa.gov/data-access/paleoclimatology-data
DATA Center Contact
Bruce
Bauer
bruce.a.bauer@noaa.gov
paleo@noaa.gov
303-497-6280
303-497-6513
325 Broadway, E/NE31
Boulder
CO
80305-3328
USA
online
ASCII
Baumgartner, M., A. Schilt, O. Eicher, J. Schmitt,
J. Schwander, R. Spahni, H. Fischer and T.F. Stocker. 2012.
High-resolution interpolar difference of atmospheric methane
around the Last Glacial Maximum.
Biogeosciences, Vol. 9, pp. 3961-3977.
doi:10.5194/bg-9-3961-2012
Reconstructions of past atmospheric methane concentrations
are available from ice cores from both Greenland
and Antarctica. The difference observed between the two polar
methane concentration levels represents a valuable constraint
on the geographical location of the methane sources.
Here we present new high-resolution methane records from
the North Greenland Ice Core Project (NGRIP) and the European
Project for Ice Coring in Antarctica (EPICA) Dronning
Maud Land (EDML) ice cores covering Termination 1,
the Last Glacial Maximum, and parts of the last glacial back
to 32 000 years before present. Due to the high resolution of
the records, the synchronisation between the ice cores from
NGRIP and EDML is considerably improved, and the interpolar
concentration difference of methane is determined with
unprecedented precision and temporal resolution. Relative
to the mean methane concentration, we find a rather stable
positive relative interpolar difference throughout the record
with its minimum value of 3.7±0.7% between 21 900–
21 200 years before present, which is higher than previously
estimated in this interval close to the Last Glacial Maximum.
This implies that Northern Hemisphere boreal wetland
sources were never completely shut off during the peak
glacial, as suggested from previous bipolar methane concentration
records. Starting at 21 000 years before present, i.e.
several millennia prior to the transition into the Holocene,
the relative interpolar difference becomes even more positive
and stays at a fairly stable level of 6.5±0.8% during
Termination 1. We thus find that the boreal and tropical
methane sources increased by approximately the same factor
during Termination 1. We hypothesise that latitudinal shifts
in the Intertropical Convergence Zone (ITCZ) and the monsoon
system contribute, either by dislocation of the methane
source regions or, in case of the ITCZ, also by changing the
relative atmospheric volumes of the Northern and Southern
Hemispheres, to the subtle variations in the relative interpolar
concentration difference on glacial/interglacial as well as
on millennial time scales.
STUDY NOTES: Methane (CH4) record from the EPICA Dronning Maud Land ice core, Antarctica, and the North Greenland Ice Sheet Project (NGRIP) ice core, Greenland, covering 32-11KYrBP.
GET DATA
https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/maud/edml2012ch4.txt
GET DATA
https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/ngrip/gases/ngrip2012ch4.txt
USA/NOAA
DIF
Version 9.8.4
2018-12-11
2018-12-11