noaa-icecore-17845 GRIP Ice Core Dielectric Profiling and Electrical Conductivity Data Wolff, E.W.; Moore, J.C.; Clausen, H.B.; Hammer, C.U. GRIP Ice Core Dielectric Profiling and Electrical Conductivity Data 1997-11-30 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/17845 Investigator E.W. Wolff Investigator J.C. Moore Investigator H.B. Clausen Investigator C.U. Hammer earth science paleoclimate ice cores depth at sample start,null,null,meter,null,ice cores,null,null,N,null earth science paleoclimate ice cores ice age at sample start,null,null,calendar year before present,null,ice cores,null,null,N,null earth science paleoclimate ice cores electrical conductivity,bulk ice,null,micromole,null,ice cores,null,direct current electrical conductivity measurement,N,null earth science paleoclimate ice cores electrical conductivity,bulk ice,null,microequivalent per kilogram,null,ice cores,null,direct current electrical conductivity measurement,N,null earth science paleoclimate ice cores electrical conductivity,bulk ice,null,microsiemens per meter,null,ice cores,null,dielectric profiling,N,null earth science paleoclimate ice core physical properties geoscientificInformation 247618 cal yr BP 466 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 Eric W. Wolff, John C. Moore, Henrik B. Clausen, Claus U. Hammer 1997 Journal of Geophysical Research: Oceans 102 C12 26325-26332 10.1029/96JC02223 http://onlinelibrary.wiley.com/enhanced/doi/10.1029/96JC02223/

High-resolution continuous profiles were obtained on the Greenland Ice Core Project (GRIP) ice core using two different electrical methods. After correction for temperature and density, the electrical conductivity method (ECM) technique responds only to acidity, while dielectric profiling (DEP) responds to acid, ammonium, and chloride. Detailed chemistry on a section of glacial-age ice allows us to confirm the calibration factor for chloride in DEP. Acidity dominates the DEP variability in the Holocene, Allerod/Bolling, and larger interstadials; ammonium dominates in the Younger Dry as, while chloride is the major contributor in cold periods including smaller interstadials. From the electrical signals plotted on a linear timescale we can deduce the background (nonvolcanic) acidity of the ice, varying from always acidic in the Holocene to always alkaline in the cold periods. In the interstadials, the ice is close to neutral, with most of it acidic in larger interstadials, most of it alkaline in smaller ones, and rapid alternations within interstadials. It is not clear whether neutralization of individual acidic particles occurred in the atmosphere or whether acid and alkaline particles coexisted until deposition in the snowpack. The changes in acidity observed at GRIP apply at least to all of Greenland and probably to much of North America. There would have been ecological effects and important changes in the uptake of some chemicals onto ice. If acidic sulfate particles were neutralized and removed from the atmosphere, which remains uncertain, then there are atmospheric chemistry and radiative effects that require further investigation. STUDY NOTES: GRIP Ice Core Dielectric Profiling (DEP) and Electrical Conductivity (ECM) Data. The files dep1.dat, dep2.dat, etc. contain DEP (dielectric profiling) data from the GRIP ice core drilled at Summit, Greenland at 2 cm resolution. The file gripdep.dat contains averages over a 55 cm interval. The ECM values were originally gathered continuously for every 1 cm of the core, but in file are averaged in 55cm intervals.

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/grip/ecm/ Data Folder; GRIP Dielectric Profiling (DEP) and Electrical Conductivity (ECM) 2 cm Data Files GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/grip/ecm/dep1.dat GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/grip/ecm/dep10.dat GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/grip/ecm/gripecm.txt Data File; GRIP Electrical Conductivity (ECM) GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/grip/ecm/dep3.dat GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/grip/ecm/dep7.dat GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/grip/ecm/gripdep.txt Data File; GRIP Dielectric Profiling (DEP) and Electrical Conductivity (ECM) Averaged GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/grip/ecm/dep5.dat GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/grip/ecm/dep8.dat GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/grip/ecm/depinfo.txt Information File; GRIP Dielectric Profiling (DEP) and Electrical Conductivity (ECM) Readme File GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/grip/ecm/dep2.dat GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/grip/ecm/dep9.dat GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/grip/ecm/dep4.dat GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/grip/ecm/dep6.dat USA/NOAA DIF Version 9.8.4 2018-12-11 2018-12-11