NGRIP CH4 concentration from 120 to 10 kyr before present and its relation to a delta N-15 temperature reconstruction from the same ice coreShow others and affiliations
Responsible organisation
2014 (English)In: Climate of the Past, ISSN 1814-9324, E-ISSN 1814-9332, Vol. 10Article in journal (Refereed) Published
Abstract [en]
During the last glacial cycle, Greenland temperature showed many rapid temperature variations, the so-called Dansgaard-Oeschger (DO) events. The past atmospheric methane concentration closely followed these temperature variations, which implies that the warmings recorded in Greenland were probably hemispheric in extent. Here we substantially extend and complete the North Greenland Ice Core Project (NGRIP) methane record from the Preboreal Holocene (PB) back to the end of the last interglacial period with a mean time resolution of 54 yr. We relate the amplitudes of the methane increases associated with DO events to the amplitudes of the local Greenland NGRIP temperature increases derived from stable nitrogen isotope (delta N-15) measurements, which have been performed along the same ice core (Kindler et al., 2014). We find the ratio to oscillate between 5 parts per billion (ppb) per degrees C and 18 ppb degrees C-1 with the approximate frequency of the precessional cycle. A remarkably high ratio of 25.5 ppb degrees C-1 is reached during the transition from the Younger Dryas (YD) to the PB. Analysis of the timing of the fast methane and temperature increases reveals significant lags of the methane increases relative to NGRIP temperature for DO events 5, 9, 10, 11, 13, 15, 19, and 20. These events generally have small methane increase rates and we hypothesize that the lag is caused by pronounced northward displacement of the source regions from stadial to interstadial. We further show that the relative interpolar concentration difference (rIPD) of methane is about 4.5% for the stadials between DO events 18 and 20, which is in the same order as in the stadials before and after DO event 2 around the Last Glacial Maximum. The rIPD of methane remains relatively stable throughout the full last glacial, with a tendency for elevated values during interstadial compared to stadial periods.
Place, publisher, year, edition, pages
2014. Vol. 10
Keywords [en]
last glacial period comparison project wetchimp atmospheric nitrous-oxide global wetland extent orbital-scale changes abrupt climate-change methane emissions millennial-scale polar ice ocean circulation Geology Meteorology & Atmospheric Sciences
Research subject
SWEDARCTIC 1997, NordGRIP 1997; SWEDARCTIC 1998, NordGRIP 1998; SWEDARCTIC 1999, NordGRIP 1999; SWEDARCTIC 2000, NordGRIP 2000; SWEDARCTIC 2001, NordGRIP 2001; SWEDARCTIC 2002, NordGRIP 2002; SWEDARCTIC 2003, NordGRIP 2003; SWEDARCTIC 2004, NordGRIP 2004
Identifiers
URN: urn:nbn:se:polar:diva-1884DOI: 10.5194/cp-10-903-2014OAI: oai:DiVA.org:polar-1884DiVA, id: diva2:810841
Note
ISI Document Delivery No.: AG4FL Times Cited: 3 Cited Reference Count: 85 Baumgartner, M. Kindler, P. Eicher, O. Floch, G. Schilt, A. Schwander, J. Spahni, R. Capron, E. Chappellaz, J. Leuenberger, M. Fischer, H. Stocker, T. F. Chappellaz, Jerome/A-4872-2011 University of Bern; Swiss National Science Foundation; Prince Albert II of Monaco Foundation; LEFE program of CNRS/INSU; Denmark (SHF); Belgium (FNRS-CFB); France (IPEV); France (INSU/CNRS); Germany (AWI); Iceland (RannIs); Japan (MEXT); Sweden (SPRS); Switzerland (SNF); United States of America (NSF); United States of America (Office of Polar Programs); European Union [243908] This work, which is a contribution to the North Greenland Ice Core Project (NGRIP), was supported by the University of Bern, the Swiss National Science Foundation, and the Prince Albert II of Monaco Foundation. Additional support was provided by the LEFE program of CNRS/INSU. NGRIP is coordinated by the Department of Geophysics at the Niels Bohr Institute for Astronomy, Physics and Geophysics, University of Copenhagen. It is supported by Funding Agencies in Denmark (SHF), Belgium (FNRS-CFB), France (IPEV and INSU/CNRS), Germany (AWI), Iceland (RannIs), Japan (MEXT), Sweden (SPRS), Switzerland (SNF) and the United States of America (NSF, Office of Polar Programs). The research leading to these results has received funding from the European Union's Seventh Framework program (FP7/2007-2013) under grant agreement no. 243908, Past4Future. Climate change - Learning from the past climate. This is Past4Future contribution no. 71. 3 Copernicus gesellschaft mbh Gottingen Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences
2015-05-082015-05-062017-12-04