GRIP Acidity, 4000 YearsEntry ID: NOAA_NCDC_PALEO_GRIP_ACIDITY
Abstract: This data set contains the GRIP acidity record, as calculated from electrical
Data consists of:
1) Depth in m below the snow surface at a local maximum in the ECM record.
2) Age at the local acid peak in years BP 1950
3) Number of years of high acidity at the local acid peak.
4,5) The mean acid concentration and background concentration in the years of
high acidity ... in micro equivalent H+ per kg of ice (ueq/kg). The data for the
past 2000 years are shown on Fig. 3b in Clausen,et al. (1997). Hammer, (1980)
and Clausen et al., (1995) describe how the current measured by ECM is
converted into concentration of acid.
6) These data are the difference between the data of #4 and #5. The
concentrations above the background are of course not all of volcanic origin
but they contain the candidates for the major acid producing volcanism.
7) The peak concentration value of strong acid detected in a 1cm sample.
8) The amount of the volcanic acid deposited at the surface during the years of
high acidity (called VAD). The amount is calculated as kg sulphuric acid per
square kilometer over the time period of enhanced acidity from the
concentration in #6 and corrected for the effect of the thinning of the annual
layers due to glacier flow. The VAD is calculated as sulphuric acid,
irrespective of the actual anion. Sulphate is the dominant anion in acid
volcanic fall-out, but in some cases hydrochloric acid and more seldom
hydrofluoric acid are present, and in the case of Dye 3 presence of nitric
acid, which does not have a volcanic origin. These data are shown on Fig. 4a -
4d in Clausen et al., (1997).
9) The magnitude of the eruption (the released amount of acid gases into the
atmosphere) is expressed in Mtons of sulphuric acid. The magnitude is
calculated by comparing the VAD to the deposited amount of total beta-activity
from known atmospheric thermonuclear tests at high northern latitude (HNL) and
low northern latitude (LNL), Refs. 4 and 5. The calculation assumes an eruption
site at HNL for comparative reasons. Some of the data are shown in column (10)
of Table 3 in Clausen et al., (1997).
Data Set Citation
Dataset Originator/Creator: Clausen, H.B., C.U. Hammer, C.S. Hvidberg, D. Dahl-Jensen, J.P. Steffensen, J. Kipfstuhl, and M.R. Legrand
Dataset Title: GRIP Acidity
Dataset Series Name: The Greenland Summit Ice Cores CD-ROM
Dataset Release Date: 1997
Dataset Release Place: Boulder, CO
Dataset Publisher: WDC/Paleoclimatology
Other Citation Details: National Snow and Ice Data Center, University of Colorado at Boulder
Paleo Temporal Coverage
Paleo Start Date: 4000 ybp
Paleo Stop Date: 0 ybp
Data Set Progress
Distribution Media: online ftp, www, CD-ROM
Distribution Format: ascii
Email: hbc at gfy.ku.dk
The Niels Bohr Institute Department of Geophysics University of Copenhagen
City: Juliane Maries Vej 30
Province or State: Copenhagen O
Postal Code: DK2100
Clausen, H.B., C.U. Hammer, C.S. Hvidberg, D. Dahl-Jensen, J.P. Steffensen,
J. Kipfstuhl, and M.R. Legrand. 1997. A comparison of the volcanic records
over the past 4000 years from the Greenland Ice Core Project and Dye 3
Greenland ice cores. Journal of Geophysical Research 102:26707-26723.
Wolff, E.W., J.C. Moore, H.B. Clausen, and C.U. Hammer. 1997. Climatic
implications of background acidity and other chemistry derived from
electrical studies of the Greenland Ice Core Project ice core. Journal of
Geophysical Research 102:26325-26332.
Clausen, H.B., C.U. Hammer, J. Christensen, C.S. Hvidberg, D. Dahl-Jensen,
M.R. Legrand, and J.P. Steffensen. 1995. 1250 years of global volcanism as
revealed by central Greenland ice cores. Ice Core Studies of Global
Biogeochemical cycles, annecy, France, R. Delmas (ed.). NATO Advanced
Sciences Institutes Series 1, 30:175-194.
Wolff, E.W., J.C. Moore, H.B. Clausen, C.U. Hammer, J. Kipfstuhl, and K.
Fuhrer. 1995. Long-term changes in the acid and salt concentrations of the
Greenland Ice Core Project ice core from electrical stratigraphy. Journal
of Geophysical Research 100:16249-16263.
Moore, J.C., E.W. Wolff, H.B. Clausen, C.U. Hammer, M.R. Legrand, and K.
Fuhrer. 1994. Electrical response of the Summit-Greenland ice core to
ammonium, sulphuric acid, and hydrochloric acid. Geophysical Research
Moore, J.C., R. Mulvaney, and J.G. Paren. 1989. Dielectric stratigraphy of
ice: a new technique for determining total ionic concentrations in polar
ice cores. Geophysical Research Letters 16:1177-1180.
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Creation and Review Dates
DIF Creation Date: 2005-05-19
Last DIF Revision Date: 2005-05-19