Insight Into Radio‐Isotope ¹²⁹I Deposition in Fresh Snow at a Remote Glacier Basin of Northeast Tibetan Plateau, China

Abstract

We present data of 129I deposition in fresh snow in the Laohugou glacier basin, northeast Tibetan Plateau, in summer 2016 and 2017, and trace its source and elevational distribution in the troposphere. Our results show that the 129I/127I atomic ratios in the fresh snow on the glacier surface are about 2 orders of magnitude larger than those in the Antarctic fresh snow and 4 orders the prenuclear level, indicating a predominantly anthropogenic source of the 129I in the mountain glacier environment of northeast Tibetan Plateau. The 129I level in the Laohugou glacier basin is 1–2 orders of magnitude lower than at representative European locations, and not significantly higher than that observed at other sites in Asia. The 129I/127I atomic ratio and 129I level show clear increases with elevation from 4,300 to 5,100 m above sea level. The 129I in the Laohugou glacier basin is probably deposited from the upper troposphere where there exists a local maximum of 129I. A conceptual model for interpretation of the observed 129I concentration and profile in Laohugou is provided. Thus, this work is of importance in providing a more complete view on the transport, dispersion, and removal of 129I in the atmosphere.

A Complete Isotope (δ15N, δ18O, Δ17O) Investigation of Atmospherically Deposited Nitrate in Glacial‐Hydrologic Systems Across the Third Pole Region

“…Another consideration for the spatial heterogeneity of snow nitrate isotopic composition is the extremely localized meteorological condition and oxidation chemistry. Altitude‐dependent variation of 129 I was observed in the same glacier and was suggested as a result of complex transport, dispersion, and removal processes in the regional and localized atmosphere (Dong et al, 2018), but a clear relationship between altitude and snow nitrate Δ 17 O composition is not found in our limited data. We have demonstrated that postdepositional photolytic loss is negligible at this site, and thus, localized snowpack photolysis and recycling may not explain the high heterogeneity of snow nitrate Δ 17 O composition.…”

Temporal variation in <sup>129</sup>I and <sup>127</sup>I in aerosols from Xi'an, China: influence of East Asian monsoon and heavy haze events

“…A recent study has confirmed that particulate iodine around two coal plants in Nanchang city, China, was greatly increased up to 36 ng m −3 , and iodine concentrations within 9 km from the coal plants were much higher than that in non-coal sites (Duan, 2018). Coal is dominant in energy consumption structure.…”

Contaminant Emissions As Indicators of Chemical Elements in The Snow Along a Latitudinal Gradient in Southern Andes

“…Light absorbing impurities derived from atmospheric pollution cause a darkening effect, reducing the albedo of snow and ice, as found in the remote Tibetan Plateau and Himalayas sites 4,48 . Mechanisms explaining the light-absorption by impurities in the snow of the high Andes Mountains have been found to change with latitude, being dust the main source of albedo reduction in northernmost regions 44 .…”

“…Gaseous and particulate matter contaminants emitted from industrialized areas are easily dispersed in the atmosphere, reaching remote regions worldwide such as the poles and high-altitude mountains [1][2][3] . These atmospheric particles act as dispersal vectors for elements, many of them potentially toxic to plants and animals, with a fraction of them being eventually deposited upon snow 4 . Once the polluted snow melts, depending on their characteristics (e.g., organic or inorganic), these particles can be transported downstream, thus contaminating water used for human consumption or farming 5,6 .…”