 |
| Titel |
Centennial to millennial variations of atmospheric methane during the early Holocene |
| VerfasserIn |
Ji-woong Yang, Jinho Ahn, Edward Brook |
| Konferenz |
EGU General Assembly 2015
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250108390
|
| Publikation (Nr.) |
 EGU/EGU2015-8144.pdf |
|
|
|
|
|
| Zusammenfassung |
| Atmospheric CH4 is one of the most important greenhouse gases. Ice core studies revealed
strong correlations between millennial CH4 variations and Greenland climate during the last
glacial period. However, millennial to sub-millennial CH4 variations during interglacial
periods are not well studied. Recently, several high-resolution data sets have been produced
for the late Holocene, but it is difficult to distinguish natural- from anthropogenic
changes. In contrast, the methane budget of the early Holocene is not affected by
anthropogenic disturbances, thus may help us better understand natural CH4 control
mechanisms under interglacial climate boundary conditions. Here we present our new
high-precision and high-resolution atmospheric CH4 record from Siple Dome ice core,
Antarctica that covers the early Holocene. We used our new wet extraction system at
Seoul National University that shows a good precision of ~1 ppb. Our data show
several tens of ppb of centennial- to millennial CH4 variations and an anti-correlative
evolution with Greenland climate on the millennial time scale. The CH4 record
could have been affected by many different types of forcing, including temperature,
precipitation (monsoon intensity), biomass burning, sea surface temperature, and solar
activity. According to our data, early Holocene CH4 is well correlated with records
of hematite stained grains (HSG) in North Atlantic sediment records, within age
uncertainties. A red-noise spectral analysis yields peaks at frequencies of ~1270 and ~80
years, which are similar to solar frequencies, but further investigations are needed to
determine major controlling factor of atmospheric CH4during the early Holocene. |
|
|
|
|
|
|