noaa-icecore-17879 GRIP Ice Core 40KYr Methane Data Blunier, T.; Chappellaz, J.A.; Schwander, J.; Stauffer, B.; Raynaud, D. GRIP Ice Core 40KYr Methane Data 1997-11-30 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/17879 Investigator T. Blunier Investigator J.A. Chappellaz Investigator J. Schwander Investigator B. Stauffer Investigator D. Raynaud earth science paleoclimate climate forcing|ice cores methane,bulk atmosphere,two standard deviations lower bound,parts per billion,null,climate forcing|ice cores,corrected,gas chromatography|wet extraction,N,null earth science paleoclimate climate forcing|ice cores methane,bulk atmosphere,two standard deviations upper bound,parts per billion,null,climate forcing|ice cores,corrected,gas chromatography|wet extraction,N,null earth science paleoclimate climate forcing|ice cores methane,bulk atmosphere,two standard deviations lower bound,parts per billion,null,climate forcing|ice cores,corrected,gas chromatography|mechanical dry extraction,N,null earth science paleoclimate climate forcing|ice cores methane,bulk atmosphere,null,parts per billion,null,climate forcing|ice cores,corrected,gas chromatography|wet extraction,N,null earth science paleoclimate climate forcing|ice cores methane,bulk atmosphere,two standard deviations upper bound,parts per billion,null,climate forcing|ice cores,corrected,gas chromatography|mechanical dry extraction,N,null earth science paleoclimate ice cores depth,null,null,meter,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,corrected,gas chromatography|mechanical dry extraction,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 ice core atmospheric gas geoscientificInformation 39408 cal yr BP 175 cal yr BP Complete 72.58 72.58 -37.63 -37.63 Continent North America Greenland GRIP>LATITUDE 72.58>LONGITUDE -37.63 None Please cite original publication, online resource, dataset and publication DOIs (where available), and date accessed when using downloaded data. If there is no publication information, please cite investigator, title, online resource, and date accessed. The appearance of external links associated with a dataset does not constitute endorsement by the Department of Commerce/National Oceanic and Atmospheric Administration of external Web sites or the information, products or services contained therein. For other than authorized activities, the Department of Commerce/NOAA does not exercise any editorial control over the information you may find at these locations. These links are provided consistent with the stated purpose of this Department of Commerce/NOAA Web site. 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

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Boulder CO 80305-3328 USA online ASCII T. Blunier, J. Chappellaz, J. Schwander, B. Stauffer and D. Raynaud 1995 Nature 374 6517 46-49 10.1038/374046a0 http://www.nature.com/nature/journal/v374/n6517/abs/374046a0.html

Records of the variation in atmospheric methane concentration have been obtained from ice cores for the past 1,000 years and for the period 8,000-220,000 yr BP, but data for the intervening period, spanning most of the present interglacial period (Holocene), are patchy. Here we present a continuous, high-resolution record of atmospheric methane from 8,000 to 1,000 yr BP, from the GRIP ice core in central Greenland. Unlike most other climate proxies from ice cores (such as oxygen isotope composition and electrical conductivity), methane concentrations show significant variations - up to 15% - during the Holocene. We have proposed that variations in the hydrological cycle at low latitudes are the dominant control on past levels of atmospheric methane. This is now supported by the observation that the lowest methane concentrations in our new record occur in the mid-Holocene, when many tropical lakes dried up. The concentration increases during the Late Holocene, probably owing to an increasing contribution from northern wetlands. STUDY NOTES: The measurements presented have been performed in Bern with a dry extraction technique and in Grenoble with a melting-refreezing method. In both laboratories the extracted air is analysed by gas chromatography.

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/grip/gases/gripch4.txt Data File; GRIP Methane Data USA/NOAA DIF Version 9.8.4 2018-12-11 2018-12-11