Dome Fuji, Antarctica Core DF1 1-cm Electrical Conductivity Measurements (ECM) Fujita, S.; Azuma, N.; Motoyama, H.; Kameda, T.; Narita, H.; Fujii, Y.; Watanabe, O. Fujita, S. Azuma, N. Motoyama, H. Kameda, T. Narita, H. Fujii, Y. Watanabe, O. earth science/paleoclimate/ice cores (electrical conductivity,bulk ice,null,dimensionless,null,ice cores,null,alternating current electrical conductivity measurement,N,AC loss factor) earth science/paleoclimate/ice cores (depth,null,null,meter,null,ice cores,null,null,N,null) earth science/paleoclimate/ice cores (electrical conductivity,bulk ice,null,microampere,null,ice cores,null,direct current electrical conductivity measurement,N,null) earth science/paleoclimate/ice core (Dome Fuji>LATITUDE -77.32>LONGITUDE 38.7) The 320 kyr climatic record from the 2503 m Dome Fuji (Antarctica) ice core was analyzed using two electrical methods: AC-ECM and ECM (electrical conductivity measurements). AC-ECM is a method to detect the complex admittance between electrodes dragged on the ice surface with mm-scale resolution and uses 1V and 1MHz. The ratio of the real to imaginary part of the admittance is the AC loss factor, which responds linearly to the amount of sulfuric acid and hydrogen ions. Both the AC loss factor and the ECM current respond to acid, but the ECM signal tends to saturate at high acidities. Dome Fuji ice was measured to be highly acidic, with background values of 2-7 uM, and had >500 major peaks with acidities of up to 90 uM. This ice-core evidence and earlier snow-chemistry survey around the dome region indicates that Dome F may have a better connection to the stratosphere than have sites at lower altitude, which allows more stratospheric aerosol and gases to reach the snow surface. Acidity tends to be high in interglacial periods, but correlation between acidity and d18O is not straightforward. Electrical signals decreased and smoothed out with increasing depth; the diffusion coefficients deduced from this smoothing were 10-102 times greater than in solid ice. The ice core exhibited electromechanical effects and expelling effects from sulfate peaks. STUDY NOTES: The climatic record from the 2503m Dome Fuji (Antarctica) ice core was analyzed using ECM (electrical conductivity measurements). The ECM current respond to acid. Dome Fuji ice was measured to be highly acidic, with background values of 2-7 micro M, and had 4500 major peaks with acidities of up to 90 micro M. Method is as follows. After equilibrating for 1 day at the cold-room temperature at Dome F, all core sections, which were 93mm in diameter and about 1.7m long, were cut parallel to their central axes into 60% and 40% portions by volume. The cut surfaces of the 60% portions were further finished with a microtome knife to make fresh, smooth surfaces. Immediately after a surface was cut and finished, two ECM electrodes were dragged along the surface with a 1250V d.c. potential difference. The entire ice core from depths of 112.65 to 2503.07m was covered by the measurements. Although the signal was sampled every 2mm, we plot only 10mm running averages of the data to remove noise. The ECM electrodes were manually dragged along the ice. The electrodes were aligned perpendicular to the core axis and 15mm apart. The effective resolution of the electrodes approximately equaled the distance between the electrodes (15mm); based on a physical principle that the electrical field decreases inversely proportional to the distance from a given location to each electrode. Within this distance, about 65% of the lines of electrical force cross. Measurement temperature is described in Fujita et al.(2002). All of the measured data were converted to values equivalent to -25C. For details, please see Fujita et al.(2002). NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Fujita, S. Investigator : Azuma, N. Investigator : Motoyama, H. Investigator : Kameda, T. Investigator : Narita, H. Investigator : Fujii, Y. Investigator : Watanabe, O. 2015-05-15 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/18676 https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/domefuji/df1ac-ecm1cm.txt https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/domefuji/df1ecm1cm.txt https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/domefuji/df1ac-ecm1cm.txt https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/domefuji/df1ecm1cm.txt English https://www.ncdc.noaa.gov/paleo/study/18676 https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/domefuji/df1ac-ecm1cm.txt https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/domefuji/df1ecm1cm.txt Fujita, Shuji; Azuma, Nobuhiko; Motoyama, Hideaki; Kameda, Takao; Narita, Hideki; Fujii, Yoshiyuki; Watanabe, Okitsugu2002Electrical measurements from the 2503-m Dome F antarctic ice coreAnnals of Glaciology351313-32010.3189/172756402781816951http://www.ingentaconnect.com/content/igsoc/agl/2002/00000035/00000001/art00052 START YEAR: 341096 cal yr BP * END YEAR: 2530 cal yr BP 38.7 -77.32 38.7 -77.32