Polar ice cores

Neftel, A., Moor, E., Oeschger, H. and Stauffer, B. (1985). Evidence from polar ice cores for the... 

The application of glaciochemical horizons to ice core dating is a recent and rapidly evolving development. A concerted search is under way to determine the impact of known events on the chemical composition of polar snow. So far, two types of universally applicable horizons have been detected in polar ice cores volcanic eruptions and Late Wisconsin dust. 

Paleoceanography The study of the ancient oceans that seeks to reconstruct past environmental condihons by examining chemical and fossil records left in the sediments and polar ice cores. 

Plastic containers must be washed before use. Table 28-1 shows that manganese in blood serum samples increased by a factor of 7 when stored in unwashed polyethylene containers prior to analysis. In the most demanding trace analysis of lead at 1 pg/g in polar ice cores, it was observed that polyethylene containers contributed a measurable flux of 1 fg of lead per cm2 per day even after they had been soaked in acid for 7 months.4 Steel needles are an avoidable source of metal contamination in biochemical analysis. 

Sr/ Sr isotopes ratios were measured in polar ice cores of varying sample size. The 95% confidence interval, expressed as a percentage of the mean 87Sr/M Sr isotope ratio, decreased with increasing quantity of Sr measured ... 

Atmospheric concentrations of carbon dioxide have varied naturally throughout Earth s history. Present C02 concentrations, however, are now higher than any seen in at least the past 450,000 years. Recent direct measurements combined with sampling of air trapped in polar ice cores shows that the recent rise in CO, correlates well with industrialization, which began in the early 1800s, as revealed in the following graph ... 

Raisbeck GM, Yiou F, Jouzel J, Petit JR (1990) 10Be and d2H in polar ice cores as a probe of the solar variability s influence on climate. Phil Trans Royal Soc London A 330 471-480 Reedy RC, Nishiizumi K, Lai D, Arnold JR, Englert PAJ, Klein J, Middleton R, Jull AJT, Donahue DJ (1994) Simulations of terrestrial in-situ cosmogenic nuclide production. Nucl Instrum Methods Phys Res B 92 297-300... 

Fig. 9. The temporal variation in atmospheric CH4 as deduced from analysis of air bubbles trapped in polar ice cores (stars) and analysis of air samples (squares). After Craig and Chou (1983).

Staffelbach T. A., Neftel A., Stauffer B., and Jacob D. J. (1991) Formaldehyde in polar ice cores a possibility to characterize the atmospheric sink of methane in the past Nature 349, 603-605. 

Water Stable Isotopes Atmospheric Composition and Applications in Polar Ice Core Studies... 

I grand M., Jouzel J., and Raynaud D. (1994) Past climate and trace gas content of the atmosphere inferred from polar ice cores. In ERCA Publication (eds.), pp. 453-477. 

Table 2(a) Carbon dioxide data from polar ice cores. Carbon dioxide concentrations and carbon isotope values (in per mil relative to the PDB standard) are listed for the LGM ( 18-24 ka), the Holocene Epoch (1-10 ka), and the most recent pre-industrial part of the Holocene Epoch (1000-1800 AD). Key references for the CO2 data from each core site are hsted in the right-hand colunrn. The superscript letters in the data table indicate the references from which the indicated values were derived. Values for Vostok (LGM and Holocene)... 

Air bubbles and clathrate hydrates in polar ice cores have attracted considerable interest because they provide the most direct record of past atmospheric gas compositions (e.g., Raynaud et However, the processes of air clathration in polar ice sheets should be taken into account when considering gas analyses. It is known that extreme fractionation of gases in air inclusions occurs when air bubbles change into clathrate hydrates by the diffusive mass transfer of air molecules between bubbles and hydrates. To estimate the effects of hydrate formation on the distribution of atmospheric gases in deep ice, it is essential to understand the structure and physical properties of natural air hydrates. 

Polar deep ice. Polar deep ice is made of snow under a compressing process. The dielectric properties of polar ice core samples have been reported as having small values of relaxation time rand activation energy.The observation of small rvalues for the core ice samples suggests that Bjerrum defects are more numerous in polar ice than in ordinary ice. The impurity concentration of polar ice is not sufficiently high to decrease the rvalue the HCl concentration is about 2x10 mol/1 for Byrd core ice. Since we know that polar deep ice has structures of clathrate gas hydrate, imperfection in the structures and the existence of gas molecules in the ice lattice seem to affect the dielectric properties.It is well known that the dielectric properties of ice samples derived from polar deep ice that has melted and refrozen are similar to those of ordinary ice. ... 

Staffelbach T, Neftel A, Stauffer B, et al. 1991. A record of the atmospheric methane sink from formaldehyde in polar ice cores. Nature 349 603-605. 

Siegenthaler U., Friedli H., Loetscher H., Moor E., NeftelA., Oeschger H., Stauffer B. (1988) Stable-isotope ratios and concentration of C02 in air from polar ice cores. Annals Glaciol. 10, 1—6. 

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