noaa-icecore-38619 eng; USA utf8 dataset NOAA National Centers for Environmental Information ncei.info@noaa.gov https://www.ncei.noaa.gov/contact NCEI Contact Information Information for contacts at NCEI. information pointOfContact NOAA World Data Service for Paleoclimatology Data Center Contact 828-271-4800 303-497-6513 325 Broadway, E/NE31 Boulder CO 80305-3328 USA paleo@noaa.gov pointOfContact 2025-04-21 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) NOAA/WDS Paleoclimatology - Atmospheric CH4, Interpolar Difference and Excesss Methane Data from the WAIS Divide, GISP2, and NEEM Ice Cores, Last Glacial Maximum and Deglaciation 2023-10-05 publication doi:10.25921/f28c-1r24 noaa-icecore-38619 NCEI DSI 1200_02 NCEI DSI 1200_01 Riddell-Young, B. originator Riddell-Young, B. author Rosen, J. originator Rosen, J. author Brook, E.J. originator Brook, E.J. author Buizert, C. originator Buizert, C. author Martin, K. originator Martin, K. author Lee, J.E. originator Lee, J.E. author Edwards, J.S. originator Edwards, J.S. author Mühl, M. originator Mühl, M. author Schmitt, J. originator Schmitt, J. author Fischer, H. originator Fischer, H. author Blunier, T. originator Blunier, T. author NOAA National Centers for Environmental Information publisher tableDigital This archived Paleoclimatology Study is available from the NOAA National Centers for Environmental Information (NCEI), under the World Data Service (WDS) for Paleoclimatology. The associated NCEI study type is Ice Core. The data include parameters of climate forcing|ice cores with a geographic location of Greenland. The time period coverage is from 48100 to 11300 in calendar years before present (BP). See metadata information for parameter and study location details. Please cite this study when using the data. Records of past temperature, precipitation, atmospheric trace gases, and other aspects of climate and environment derived from ice cores drilled on glaciers and ice caps around the world. Parameter keywords describe what was measured in this dataset. Additional summary information can be found in the abstracts of papers listed in the dataset citations. completed NOAA National Centers for Environmental Information ncei.info@noaa.gov https://www.ncei.noaa.gov/contact NCEI Contact Information Information for contacts at NCEI. information pointOfContact NOAA World Data Service for Paleoclimatology Data Center Contact 828-271-4800 303-497-6513 325 Broadway, E/NE31 Boulder CO 80305-3328 USA paleo@noaa.gov pointOfContact https://www.ncei.noaa.gov/pub/data/paleo/webimages/pc-default-icecore.png Paleoclimatology - Ice Core PNG Earth Science > Climate Indicators > Paleoclimate Indicators > Ice Core Records Earth Science > Paleoclimate > Ice Core Records theme Global Change Master Directory (GCMD) Science Keywords 2025 revision 22 Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA) https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords GCMD Keyword Forum Page Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 22. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords information custodian earth science > paleoclimate > climate forcing|ice cores earth science > paleoclimate > climate forcing|ice cores earth science > paleoclimate > climate forcing|ice cores earth science > paleoclimate > climate forcing|ice cores earth science > paleoclimate > climate forcing|ice cores earth science > paleoclimate > climate forcing|ice cores earth science > paleoclimate > climate forcing|ice cores earth science > paleoclimate > climate forcing|ice cores earth science > paleoclimate > ice cores earth science > paleoclimate > ice cores earth science > paleoclimate > climate forcing|ice cores earth science > paleoclimate > climate forcing|ice cores earth science > paleoclimate > climate forcing|ice cores earth science > paleoclimate > climate forcing|ice cores earth science > paleoclimate > climate forcing|ice cores earth science > paleoclimate > ice cores earth science > paleoclimate > ice cores earth science > paleoclimate > climate forcing|ice cores earth science > paleoclimate > climate forcing|ice cores earth science > paleoclimate > climate forcing|ice cores earth science > paleoclimate > climate forcing|ice cores earth science > paleoclimate > climate forcing|ice cores earth science > paleoclimate > climate forcing|ice cores earth science > paleoclimate > climate forcing|ice cores earth science > paleoclimate > climate forcing|ice cores earth science > paleoclimate > ice cores earth science > paleoclimate > climate forcing|ice cores earth science > paleoclimate > climate forcing|ice cores earth science > paleoclimate > climate forcing|ice cores earth science > paleoclimate > climate forcing|ice cores earth science > paleoclimate > climate forcing|ice cores earth science > paleoclimate > climate forcing|ice cores earth science > paleoclimate > climate forcing|ice cores earth science > paleoclimate > ice cores earth science > paleoclimate > ice cores earth science > paleoclimate > climate forcing|ice cores earth science > paleoclimate > climate forcing|ice cores earth science > paleoclimate > ice core > atmospheric gas theme Global Change Master Directory (GCMD) Science Keywords 2025 revision 22 Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA) https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords GCMD Keyword Forum Page Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 22. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords information custodian Atmospheric Gas Reconstruction Last Glacial Maximum Younger Dryas carbon cycle centennial resolution theme What: methane; Material: bulk atmosphere What: methane; Material: bulk atmosphere What: methane; Material: bulk atmosphere What: methane; Material: bulk atmosphere What: methane; Material: bulk atmosphere What: methane; Material: bulk atmosphere What: methane; Material: bulk ice What: methane; Material: bulk ice What: collection date; Material: null What: methane; Material: null What: methane; Material: bulk atmosphere What: gas age; Material: null What: methane; Material: bulk atmosphere What: depth; Material: null What: methane; Material: bulk ice What: depth; Material: null What: methane; Material: null What: methane; Material: bulk atmosphere What: methane; Material: bulk atmosphere What: methane; Material: bulk atmosphere What: depth; Material: null What: depth; Material: null What: methane; Material: bulk atmosphere What: methane; Material: bulk atmosphere What: methane; Material: bulk ice What: calcium; Material: null What: methane; Material: bulk atmosphere What: methane; Material: bulk atmosphere What: methane; Material: bulk atmosphere What: methane; Material: bulk atmosphere What: methane; Material: bulk ice What: methane; Material: bulk atmosphere What: methane; Material: bulk atmosphere What: calcium; Material: null What: depth; Material: null What: gas age; Material: null What: methane; Material: bulk atmosphere theme Paleoenvironmental Standard Terms (PaST) Thesaurus NOAA National Centers for Environmental Information https://www.ncei.noaa.gov/products/paleoclimatology/paleoenvironmental-standard-terms-thesaurus PaST Thesaurus information publisher Continent > North America > Greenland > GISP2 > LATITUDE 72.583333 > LONGITUDE -38.466667 Continent > Antarctica > WAIS Divide > LATITUDE -79.463 > LONGITUDE -112.11 Geographic Region > Global > Global > LATITUDE > LONGITUDE Continent > North America > Greenland > NEEM > LATITUDE 77.45 > LONGITUDE -51.066667 place DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce dataCentre Global Change Master Directory (GCMD) Data Center Keywords 2025 revision 22 Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA) https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords GCMD Keyword Forum Page Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 22. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords information custodian otherRestrictions Cite as: Riddell-Young, B.; Rosen, J.; Brook, E.J.; Buizert, C.; Martin, K.; Lee, J.E.; Edwards, J.S.; Mühl, M.; Schmitt, J.; Fischer, H.; Blunier, T. (2023-10-05): NOAA/WDS Paleoclimatology - Atmospheric CH4, Interpolar Difference and Excesss Methane Data from the WAIS Divide, GISP2, and NEEM Ice Cores, Last Glacial Maximum and Deglaciation. [indicate subset used]. NOAA National Centers for Environmental Information. https://doi.org/10.25921/f28c-1r24. Accessed [date]. otherRestrictions Distribution liability: NOAA and NCEI make no warranty, expressed or implied, regarding these data, nor does the fact of distribution constitute such a warranty. NOAA and NCEI cannot assume liability for any damages caused by any errors or omissions in these data. If appropriate, NCEI can only certify that the data it distributes are an authentic copy of the records that were accepted for inclusion in the NCEI archives. otherRestrictions Use liability: NOAA and NCEI cannot provide any warranty as to the accuracy, reliability, or completeness of furnished data. Users assume responsibility to determine the usability of these data. The user is responsible for the results of any application of this data for other than its intended purpose otherRestrictions None otherRestrictions 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. Atmospheric methane variability through the Last Glacial Maximum and deglaciation mainly controlled by tropical sources 2023 publication Riddell-Young, Ben; Julia Rosen; Edward Brook; Christo Buizert; Kaden Martin; James Lee; Jon Edwards; Michaela Mühl; Jochen Schmitt; Hubertus Fischer; Thomas Blunier author Nature Geoscience publisher https://doi.org/10.1038/s41561-023-01332-x HTTPS Web Browser Associated Reference published 2023 Riddell-Young, Ben; Julia Rosen; Edward Brook; Christo Buizert; Kaden Martin; James Lee; Jon Edwards; Michaela Mühl; Jochen Schmitt; Hubertus Fischer; Thomas Blunier, 2023: Atmospheric methane variability through the Last Glacial Maximum and deglaciation mainly controlled by tropical sources. Nature Geoscience, 16, 1174–1180, 10.1038/s41561-023-01332-x information crossReference sciencePaper eng; USA geoscientificInformation Date Range: 48100 cal yr BP to 11300 cal yr BP; -180 180 -90 90 -46150 -9350 STUDY NOTES: Site locations - WAIS Divide: -79.468 S, -112.086 W, 1797m; GISP2: 72.583333 N, -38.466667 W, 3200m; NEEM: 77.45 N, -51.066667 W, 2450m. This study includes measurements of atmospheric methane from samples from the NEEM, GISP2 and WAIS Divide ice cores. All measurements were made at the Oregon State University Ice Core and Quaternary Geochemistry Laboratory (Corvallis, OR) using an established analytical system. 433 samples from the NEEM ice core were measured between 1420 and 1560m depths. A measurement uncertainty ranging from 2.8 to 4.2 ppb, depending on the measurement year, was determined from replicate samples. 340 samples from the GISP2 ice core were measured between 1740 and 2060m depths. A measurement uncertainty ranging from 3.1 to 3.4 ppb, depending on the measurement year, was determined from replicate samples. All GISP2 and NEEM data were corrected for excess methane contamination using the established relationship between excess methane and Ca2+ (Lee et al., 2020). Both corrected and uncorrected data are included in the publication. 340 samples from the GISP2 ice core were measured between 1957 and 3081m depths. A measurement uncertainty ranging from 3.1 to 3.4 ppb, depending on the measurement year, was determined from replicate samples. Depths reflect the mid-points of the depth range of each samples, which is typically ~8cm (Lee et al.(2020) DOI: 10.1016/j.gca.2019.11.020). This study includes estimates of the atmospheric methane relative interpolar difference (rIPD) across the Last Glacial Maximum and Deglaciation. The rIPD was calculated using discrete, high-resolution methane measurements from the WAIS Divide, NEEM and GISP2 ice cores. Two independent IPD records were determined: One using NEEM and WAIS and one using GISP2 and WAIS. The dataset includes rIPD values calculated using both Greenland methane data both corrected and uncorrected for excess methane (Lee et al., 2020). The rIPD was calculated by smoothing each methane record and synchronizing them to the WD2014 gas age scale. 1-sigma rIPD uncertainties are included. This dataset also includes the output of the four-box troposphere model used to interpret the rIPD. For both excess methane-corrected records, the model output and 1-sigma uncertainty is provided for northern extratropical (30N - 90N) and total tropical (30S - 30N) sources in Tg yr-1. For the NEEM-derived rIPD, sections of the rIPD where atmospheric methane changed rapidly were deemed untrustworthy were removed from the dataset (Lee et al.(2020) DOI: 10.1016/j.gca.2019.11.020). This study includes new measurements of in-situ, non-atmospheric methane release during the melt-refreeze analysis of ice samples for atmospheric methane measurement, also known as excess methane (CH4xs). All measurements were made at the Oregon State University Ice Core Laboratory and followed the methods of Lee et al., 2020 and Mitchell et al., 2013. Measurements were made using ice from the GISP2 and NEEM ice cores in 2018, 2019, and 2021. In total, 70 new measurements were made on NEEM ice and 406 measurements on GISP2 ice. The Ca2+ content of the ice was calculated using the published Ca2+ concentration records, and the mass and depth ranges of each sample. For GISP2, the year the measurement was made is included. Provided Keywords: Methane, Last Glacial Maximum, Deglaciation, Greenhouse gases, terrestrial biogeochemistry ABSTRACT SUPPLIED BY ORIGINATOR: Constraining the causes of past atmospheric methane variability is important for understanding links between methane and climate. Abrupt methane changes during the last deglaciation have been intensely studied for this purpose, but the relative importance of high-latitude and tropical sources remains poorly constrained. The methane interpolar concentration difference reflects past geographic emission variability, but existing records suffered from subtle but considerable methane production during analysis. Here, we report an ice-core-derived interpolar difference record covering the Last Glacial Maximum and deglaciation, with substantially improved temporal resolution, chronology and a critical correction for methane production in samples from Greenland. Using box models to infer latitudinal source changes, we show that tropical sources dominated abrupt methane variability of the deglaciation, highlighting their sensitivity to abrupt climate change and rapidly shifting tropical rainfall patterns. Northern extratropical emissions began increasing ~16,000 years ago, probably through wetland expansion and/or permafrost degradation induced by high-latitude warming, and contributed at most 25 Tg yr−1 (45% of the total emission increase) to the abrupt methane rise that coincided with rapid northern warming at the onset of the Bølling–Allerød interval. These constraints on deglacial climate–methane cycle interactions can improve the understanding of possible present and future feedbacks. NOAA National Centers for Environmental Information ncei.info@noaa.gov https://www.ncei.noaa.gov/contact NCEI Contact Information Information for contacts at NCEI. information distributor In most cases, electronic downloads of the data are free. However, fees may apply for custom orders, data certifications, copies of analog materials, and data distribution on physical media. Contact NCEI for other distribution options and instructions. Native Format(s) https://doi.org/10.25921/f28c-1r24 HTTPS Landing Page Metadata Landing Page NCEI landing page with general information and links to access the data. information https://www.ncei.noaa.gov/access/paleo-search/study/38619 HTTPS Web Browser NOAA Study Page Study page with data access information. search https://www.ncei.noaa.gov/products/paleoclimatology/ice-core HTTPS Information NCEI Ice Core Page General information for this data type. information https://www.ncei.noaa.gov/pub/data/paleo/icecore/riddell-young2023/riddell-young2023-ripd-ch4-wais-neem.txt HTTPS Download NCEI Direct Download Direct download links for dataset files. download https://www.ncei.noaa.gov/pub/data/paleo/icecore/riddell-young2023/riddell-young2023-ripd-ch4-wais-gisp2.txt HTTPS Download NCEI Direct Download Direct download links for dataset files. download https://www.ncei.noaa.gov/pub/data/paleo/icecore/riddell-young2023/riddell-young2023-ch4xs-neem.txt HTTPS Download NCEI Direct Download Direct download links for dataset files. download https://www.ncei.noaa.gov/pub/data/paleo/icecore/riddell-young2023/riddell-young2023-ch4xs-gisp2.txt HTTPS Download NCEI Direct Download Direct download links for dataset files. download https://www.ncei.noaa.gov/pub/data/paleo/icecore/riddell-young2023/riddell-young2023-atmos-ch4-wais.txt HTTPS Download NCEI Direct Download Direct download links for dataset files. download https://www.ncei.noaa.gov/pub/data/paleo/icecore/riddell-young2023/riddell-young2023-atmos-ch4-neem.txt HTTPS Download NCEI Direct Download Direct download links for dataset files. download https://www.ncei.noaa.gov/pub/data/paleo/icecore/riddell-young2023/riddell-young2023-atmos-ch4-gisp2.txt HTTPS Download NCEI Direct Download Direct download links for dataset files. download asNeeded This ISO metadata record was translated from DIF metadata using dif-9x-to-iso-19115-2.xsl Version: 2022-06-21