@article {2826,
	title = {Unifying Concepts Linking Dissolved Organic Matter Composition to Persistence in Aquatic EcosystemsUnifying Concepts Linking Dissolved Organic Matter Composition to Persistence in Aquatic Ecosystems},
	journal = {Environmental Science \& Technology},
	volume = {52},
	year = {2018},
	month = {Jun-03-2018},
	pages = {2538 - 2548},
	abstract = {The link between composition and reactivity of dissolved organic matter (DOM) is central to understanding the role aquatic systems play in the global carbon cycle; yet, unifying concepts driving molecular composition have yet to be established. We characterized 37 DOM isolates from diverse aquatic ecosystems, including their stable and radiocarbon isotopes (δ13C-dissolved organic carbon (DOC) and Δ14C-DOC), optical properties (absorbance and fluorescence), and molecular composition (ultrahigh resolution mass spectrometry). Isolates encompassed end-members of allochthonous and autochthonous DOM from sites across the United States, the Pacific Ocean, and Antarctic lakes. Modern Δ14C-DOC and optical properties reflecting increased aromaticity, such as carbon specific UV absorbance at 254 nm (SUVA254), were directly related to polyphenolic and polycyclic aromatic compounds, whereas enriched δ13C-DOC and optical properties reflecting autochthonous end-members were positively correlated to more aliphatic compounds. Furthermore, the two sets of autochthonous end-members (Pacific Ocean and Antarctic lakes) exhibited distinct molecular composition due to differences in extent of degradation. Across all sites and end-members studied, we find a consistent shift in composition with aging, highlighting the persistence of certain biomolecules concurrent with degradation time.},
	issn = {0013-936X},
	doi = {10.1021/acs.est.7b0551310.1021/acs.est.7b05513.s001},
	url = {https://pubs.acs.org/doi/10.1021/acs.est.7b05513},
	author = {Kellerman, Anne M. and Guillemette, Fran{\c c}ois and Podgorski, David C. and Aiken, George R. and Butler, Kenna D. and Spencer, Robert G. M.}
}
@article {2458,
	title = {Anthropogenic aerosols as a source of ancient dissolved organic matter in glaciers},
	journal = {Nature Geoscience},
	volume = {5},
	year = {2012},
	month = {Jul-02-2013},
	pages = {198 - 201},
	abstract = {Glacier-derived dissolved organic matter represents a quantitatively significant source of ancient, yet highly bioavailable carbon to downstream ecosystems1. This finding runs counter to logical perceptions of age{\textendash}reactivity relationships, in which the least reactive material withstands degradation the longest and is therefore the oldest2. The remnants of ancient peatlands and forests overrun by glaciers have been invoked as the source of this organic matter1, 3, 4. Here, we examine the radiocarbon age and chemical composition of dissolved organic matter in snow, glacier surface water, ice and glacier outflow samples from Alaska to determine the origin of the organic matter. Low levels of compounds derived from vascular plants indicate that the organic matter does not originate from forests or peatlands. Instead, we show that the organic matter on the surface of the glaciers is radiocarbon depleted, consistent with an anthropogenic aerosol source. Fluorescence spectrophotometry measurements reveal the presence of protein-like compounds of microbial or aerosol origin. In addition, ultrahigh-resolution mass spectrometry measurements document the presence of combustion products found in anthropogenic aerosols. Based on the presence of these compounds, we suggest that aerosols derived from fossil fuel burning are a source of pre-aged organic matter to glacier surfaces. Furthermore, we show that the molecular signature of the organic matter is conserved in snow, glacier water and outflow, suggesting that the anthropogenic carbon is exported relatively unchanged in glacier outflows.},
	keywords = {Atmospheric chemistry, Biogeochemistry, Cryospheric science},
	issn = {1752-0894},
	doi = {10.1038/ngeo1403},
	url = {http://www.nature.com/doifinder/10.1038/ngeo1403},
	author = {Stubbins, Aron and Hood, Eran and Raymond, Peter A. and Aiken, George R. and Sleighter, Rachel L. and Hernes, Peter J. and Butman, David and Hatcher, Patrick G. and Striegl, Robert G. and Schuster, Paul and Abdulla, Hussain A. N. and Vermilyea, Andrew W. and Scott, Durelle T. and Spencer, Robert G. M.}
}
