noaa-icecore-20528 NEEM Ice Core 120,000 Year Bromine and Sodium Data Spolaor, A.; Vallelonga, P.; Turetta, C.; Maffezzoli, N.; Cozzi, G.; Gabrieli, J.; Barbante, C.; Goto-Azuma, K.; Saiz-Lopez, A.; Cuevas, C.A.; Dahl-Jensen, D. NEEM Ice Core 120,000 Year Bromine and Sodium Data 2016-09-23 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/20528 Investigator A. Spolaor Investigator P. Vallelonga Investigator C. Turetta Investigator N. Maffezzoli Investigator G. Cozzi Investigator J. Gabrieli Investigator C. Barbante Investigator K. Goto-Azuma Investigator A. Saiz-Lopez Investigator C.A. Cuevas Investigator D. Dahl-Jensen earth science paleoclimate ice cores bromine,bulk ice,null,nanogram per gram,null,ice cores,null,inductively-coupled plasma field sector mass spectrometry,N,null earth science paleoclimate ice cores depth,null,null,meter,null,ice cores,null,null,N,null earth science paleoclimate ice cores delta 18O,bulk ice,null,per mil SMOW,null,ice cores,null,cavity ring-down spectroscopy,N,null earth science paleoclimate ice cores sodium,bulk ice,null,nanogram per gram,null,ice cores,null,inductively-coupled plasma field sector mass spectrometry,N,null earth science paleoclimate ice cores bromine,bulk ice,null,dimensionless,null,ice cores,null,null,N,bromine enrichment value earth science paleoclimate ice core chemistry geoscientificInformation sea ice 120295 cal yr BP -24 cal yr BP Complete 77.45 77.45 -51.06 -51.06 Continent North America Greenland NEEM>LATITUDE 77.45>LONGITUDE -51.06 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 Andrea Spolaor, Paul Vallelonga, Clara Turetta, Niccolo Maffezzoli, Giulio Cozzi, Jacopo Gabrieli, Carlo Barbante, Kumiko Goto-Azuma, Alfonso Saiz-Lopez, Carlos A. Cuevas, and Dorthe Dahl-Jensen 2016 Scientific Reports 33925 6 10.1038/srep33925 http://dx.doi.org/10.1038/srep33925

Reconstructing the past variability of Arctic sea ice provides an essential context for recent multi-year sea ice decline, although few quantitative reconstructions cover the Holocene period prior to the earliest historical records 1,200 years ago. Photochemical recycling of bromine is observed over first-year, or seasonal, sea ice in so-called "bromine explosions" and we employ a 1-D chemistry transport model to quantify processes of bromine enrichment over first-year sea ice and depositional transport over multi-year sea ice and land ice. We report bromine enrichment in the Northwest Greenland Eemian NEEM ice core since the end of the Eemian interglacial 120,000 years ago, finding the maximum extension of first-year sea ice occurred approximately 9,000 years ago during the Holocene climate optimum, when Greenland temperatures were 2 to 3C above present values. First-year sea ice extent was lowest during the glacial stadials suggesting complete coverage of the Arctic Ocean by multi-year sea ice. These findings demonstrate a clear relationship between temperature and first-year sea ice extent in the Arctic and suggest multi-year sea ice will continue to decline as polar amplification drives Arctic temperatures beyond the 2C global average warming target of the recent COP21 Paris climate agreement. STUDY NOTES: Bromine, sodium and bromine enrichment data used to reconstruct Canadian Arctic sea ice over the past 120 ky

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/neem/neem2016br.txt Data File; NEEM Ice Core Bromine, Sodium, and Bromine Enrichment Data USA/NOAA DIF Version 9.8.4 2019-03-19 2019-03-19