Temporal variations of mineral dust, biogenic tracers, and anthropogenic species during the past two centuries from Belukha ice core, Siberian Altai

Abstract

In July 2001, a 140 m long ice core was recovered from the Belukha glacier (49°48′26″N, 86°34′43″E, 4062 m a.s.l.) in the Siberian Altai. The ion chemistry of the upper 86 m, covering the last two centuries, is characterized by biogenic emissions (ammonium and formate), aeolian dust (calcium, magnesium, chloride, and sodium) and anthropogenic species (sulfate, nitrate, and ammonium). Particularly high ammonium and formate concentrations indicate pronounced emissions from Siberian forests. The inferred fire frequency does not show a long‐term trend but distinct periods of enhanced activity. Sulfate has the highest industrial to preindustrial ratio and an anthropogenic contribution of more than 80%. Variations in this record reflect sulfur dioxide emissions in Siberia and Kazakhstan. Sulfate concentrations remained low until 1950, then sharply increased and peaked in the 1970s. The decrease in the 1980s is attributed to the economic, political, and social crises and to the replacement of coal with gas. Rising nitrate concentrations since 1960 reflect traffic growth and enhanced fertilizer application. Increasing ammonium concentrations since the 1950s are attributable to population inflow in southern Siberia with the associated enhancement of agricultural activity. A nitrate peak of short duration in 1908 is thought to be the atmospheric signature from the Tunguska event on 30 June 1908.

Microbial nitrogen cycling on the Greenland Ice Sheet

“…7a) and that NO − 3 deposition on the GrIS has doubled since preindustrial times, most likely due to fossil fuel burning (Olivier et al, 2006). The impact of anthropogenic nitrogen deposition on the total nitrogen budget of the western GrIS ablation zone is however likely to be lower than that on some high Arctic glaciers, such as those in Svalbard.…”

“…Deposition of NO − 3 on Svalbard glaciers has increased 65 % since preindustrial times due to anthropogenic deposition (largely from fossil fuel burning; Kekonen et al, 2005), substantially increasing the total nitrogen deposition on the glaciers (Hodson et al, 2005(Hodson et al, , 2010c. While NO − 3 deposition from precipitation on the GrIS has increased even more over the same period (Olivier et al, 2006), the impact as a percentage of total nitrogen inputs is likely to be ameliorated in part by the dominance of icemelt as a nitrogen input (Fig. 7a).…”

“…There have been significant increases in nitrogen deposition from anthropogenic sources on Arctic glaciers and the GrIS since preindustrial times (Kekonen et al, 2005;Olivier et al, 2006), and its impact on the nutrient-poor supraglacial environment has yet to be well established .…”

Ice sheets and nitrogen

“…factor 3 increase, 1960-1990) [19], East Rongbuk Glacier ( factor 2, 1950-1980) [38] and Belukha (factor 1.6, 1950-1980, followed by plateau) [33]. Modelling work is needed to separate out the influence of higher emissions from that of increased concentrations of sulfate and nitrate that may neutralize gaseous NH 3 , leading to greater NH 4 þ deposition.…”

Biological proxies recorded in a Belukha ice core, Russian Altai

“…The time scale was derived using the 210 Pb record, a three-parameter annual layer-counting methodology, and a nonlinear regression (Haefeli, 1961) (1963 -3 H maximum) and different volcanic eruptions Olivier et al, 2006;Eichler et al, 2009a). Volcanic horizons are marked by nondust SO 4 2− (exSO 4 2− ) concentration maxima and corresponding minima in the temperature record.…”