Insight into atmospheric deposition and spatial distribution of bioavailable iron in the glaciers of northeastern Tibetan Plateau

Jie Di; Zhiwen Dong; Eric J R Parteli; Ting Wei; Augusto Marcelli; Jiawen Ren; Xiang Qin; Shifeng Chen

doi:10.1016/j.scitotenv.2022.153946

Insight into atmospheric deposition and spatial distribution of bioavailable iron in the glaciers of northeastern Tibetan Plateau

Sci Total Environ. 2022 Jun 15:825:153946. doi: 10.1016/j.scitotenv.2022.153946. Epub 2022 Feb 18.

Authors

Jie Di¹, Zhiwen Dong², Eric J R Parteli³, Ting Wei⁴, Augusto Marcelli⁵, Jiawen Ren⁶, Xiang Qin⁶, Shifeng Chen¹

Affiliations

¹ State Key Laboratory of Cryosphere Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China.
² State Key Laboratory of Cryosphere Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing 100101, China. Electronic address: dongzhiwen@lzb.ac.cn.
³ Faculty of Physics, University of Duisburg-Essen, Duisburg 47057, Germany.
⁴ State Key Laboratory of Cryosphere Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: weiting@lzb.ac.cn.
⁵ INFN - LNF, Via E. Fermi 54, 00044 Frascati, RM, Italy; CNR - Istituto Struttura della Materia and Elettra-Sincrotrone Trieste, Basovizza Area Science Park, 34149 Trieste, Italy.
⁶ State Key Laboratory of Cryosphere Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; Qilian Mountain Glacier and Ecological Environment Research Station, Chinese Academy of Sciences, Lanzhou, China.

PMID: 35189209
DOI: 10.1016/j.scitotenv.2022.153946

Abstract

Iron (Fe) is an essential micronutrient in glacial ecosystems and modulates global biogeochemical cycles. To find out the deposition concentration, multiple origins and release form of iron in various glacier areas of central Asia, this study investigated the total Fe (TFe) and dissolved-Fe (dFe, diameter < 0.45 or <0.2 μm) deposition in glaciers and snowpack of northeast Tibetan Plateau, based on snow and meltwater sampling in ablation period of 2014-2017. The composition and concentration of dFe in the samples were measured, and the spatial distribution and temporal variations of dFe in glacial surface snow and meltwater runoff were investigated. Results showed that average TFe and dFe contents exhibited a generally heterogeneous geographic distribution that varied from north to south. The northern locations in eastern Tianshan Mountains (e.g. Miaoergou Glacier) showed the highest TFe and dFe values, followed by Yuzhufeng Glacier of eastern Kunlun Mountains, whereas the Qilian Mountains locations displayed relatively lower TFe and dFe contents spanning a wide range. Based on the good correlation between TFe and dFe, we infer that aeolian dust and anthropogenic aerosols, and their chemical interactions are likely the important origins for dFe deposition. In meltwater runoff the peak values of dFe release flux appeared in July, with maximum appeared earlier (the early of July) than TFe (the end of July). Moreover, the annual dFe release flux from Laohugou glacier terminus meltwater runoff is estimated to be 1740 kg yr^-1 (with 9256 kg yr^-1 for TFe), and meltwater showed higher mean concentration of dFe than that of glacier snowpack. We also provided a conceptual framework showing the multiple origins and transport dynamics of dissolved Fe along the atmosphere-glacier-meltwater runoff path. Compared to Fe release in other global glacier/ice-sheet, the TP glacier is an important potential dFe reservoir and may have a profound effect on regional downstream ecosystem through Fe biochemistry cycle.

Keywords: Bioavailable iron; Glacier and meltwater; Multiple origins; Northeast Tibetan Plateau; Spatial distribution.

MeSH terms

Ecosystem*
Environmental Monitoring / methods
Ice Cover* / chemistry
Iron
Tibet

Substances

Iron