The Role of Photochemistry in Driving the Composition of Dissolved Organic Matter Found in Glacier Environments ...
Dissolved organic matter (DOM) in glacier environments is aliphatic-rich, yet studies have proposed DOM originates from allochthonous, aromatic and often aged material. Allochthonous organic matter (OM) is exposed to ultraviolet radiation both in atmospheric transport and post-deposition on the glac...
Main Authors: | , , , , , , , |
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Format: | Dataset |
Language: | English |
Published: |
Interdisciplinary Earth Data Alliance (IEDA)
2021
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Subjects: | |
Online Access: | https://dx.doi.org/10.26022/ieda/111996 https://ecl.earthchem.org/view.php?id=1996 |
Summary: | Dissolved organic matter (DOM) in glacier environments is aliphatic-rich, yet studies have proposed DOM originates from allochthonous, aromatic and often aged material. Allochthonous organic matter (OM) is exposed to ultraviolet radiation both in atmospheric transport and post-deposition on the glacier surface. Thus, we evaluate photochemistry as a mechanism to account for the compositional disconnect between allochthonous OM sources and glacier DOM composition. Six solid endmember OM sources were leached in ultrapure water and photo-irradiated for 28-days in a solar simulator, until > 90 % of initial chromophoric DOM was removed. Ultrahigh-resolution mass spectrometry was used to compare the molecular composition of leachates pre- and post-irradiation to DOM sampled from supraglacial and bulk runoff from the Greenland Ice Sheet and Juneau Icefield, respectively. Photo-irradiation drove molecular level convergence between the initially aromatic-rich leachates and aromatic-poor glacial samples, selectively ... |
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