@article {2460,
	title = {Seasonal variability of organic matter composition in an Alaskan glacier outflow: insights into glacier carbon sources},
	journal = {Environmental Research Letters},
	volume = {9},
	year = {2014},
	month = {Jan-05-2014},
	pages = {055005},
	abstract = {Glacier ecosystems are a significant source of bioavailable, yet ancient dissolved organic carbon
(DOC). Characterizing DOC in Mendenhall Glacier out flow (southeast Alaska) we document a
seasonal persistence to the radiocarbon-depleted signature of DOC, highlighting ancient DOC as
a ubiquitous feature of glacier out flow. We observed no systematic depletion in Δ14C-DOC with
increasing discharge during the melt season that would suggest mobilization of an aged subglacial carbon store. However, DOC concentration, δ13C-DOC,Δ14C-DOC and fluorescence signatures appear to have been in fluenced by runoff from vegetated hillslopes above the glacier during onset and senescence of melt. In the peak glacier melt period, the Δ 14 C-DOC of stream samples at the out flow (-181.7 to-355.3{\textperthousand}) was comparable to the Δ 14 C-DOC for snow samples from the accumulation zone (-207.2 to-390.9{\textperthousand}), suggesting that ancient DOC from the glacier surface is exported in glacier runoff. The pre-aged DOC in glacier snow and runoff is consistent with contributions from fossil fuel combustion sources similar to those documented previously in ice cores and thus provides evidence for anthropogenic perturbation of the carbon cycle. Overall, our results emphasize the need to further characterize DOC inputs to glacier ecosystems, particularly in light of predicted changes in glacier mass and runoff in the coming century.},
	keywords = {alaska, dissolved organic carbon, glacier, organic matter, radiocarbon},
	doi = {10.1088/1748-9326/9/5/055005},
	url = {http://iopscience.iop.org/article/10.1088/1748-9326/9/5/055005/meta},
	author = {Spencer, Robert G M and Vermilyea, Andrew and Fellman, Jason and Raymond, Peter and Stubbins, Aron and Scott, Durelle and Hood, Eran}
}
@article {2459,
	title = {Source and biolability of ancient dissolved organic matter in glacier and lake ecosystems on the Tibetan Plateau},
	journal = {Geochimica et Cosmochimica Acta},
	volume = {142},
	year = {2014},
	month = {Jan-10-2014},
	pages = {64 - 74},
	abstract = {The Tibetan Plateau is the world{\textquoteright}s largest and highest plateau and holds the largest mass of ice on Earth outside the ice-sheets of Greenland and Antarctica, as well as abundant lakes. This study examined the molecular and isotopic signatures of dissolved organic matter (DOM) along with its biolability in glacier ice, glacier-fed streams, and alpine lakes on the Tibetan Plateau. The aim was to assess the sources of DOM and the potential of DOM to provide a carbon subsidy to downstream ecosystems. Tibetan glaciers and glacier streams exhibited low dissolved organic carbon (DOC) concentrations (17.7{\textendash}27.9 μM) and ancient DOC radiocarbon ages (749{\textendash}2350 ybp). The optical properties, stable carbon isotope ratios (δ13C-DOC) and the molecular composition (Fourier transform ion cyclotron resonance mass spectrometry) of Tibetan glacier DOM are consistent with data from other glacier systems around the world. The geochemical signatures and the ancient apparent ages of Tibetan glacier DOM suggest a significant fraction is derived from the atmospheric deposition of pre-aged, possibly fossil fuel derived organics. Within the Tibetan alpine lakes, DOC was also ancient (525{\textendash}675 ybp), due to either inputs of pre-aged organics from glacier runoff, direct deposition, or due to the aging of organics in situ (i.e. a radiocarbon reservoir effect). The glacier ice and glacier stream sites exhibited high biolability of DOC and so provide a carbon subsidy to downstream environments that will change as glaciers on the Tibetan Plateau recede.},
	issn = {00167037},
	doi = {10.1016/j.gca.2014.08.006},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0016703714005018http://api.elsevier.com/content/article/PII:S0016703714005018?httpAccept=text/xmlhttp://api.elsevier.com/content/article/PII:S0016703714005018?httpAccept=text/plain},
	author = {Spencer, Robert G.M. and Guo, Weidong and Raymond, Peter A. and Dittmar, Thorsten and Hood, Eran and Fellman, Jason and Stubbins, Aron}
}
