@article {white_refractory_2023,
	title = {Refractory Dissolved Organic Matter has Similar Chemical Characteristics but Different Radiocarbon Signatures With Depth in the Marine Water Column},
	journal = {Global Biogeochemical Cycles},
	volume = {37},
	number = {4},
	year = {2023},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2022GB007603},
	month = {04/2023},
	pages = {e2022GB007603},
	abstract = {The >5,000-year radiocarbon age (14C-age) of much of the 630 {\textpm} 30 Pg C oceanic dissolved organic carbon (DOC) reservoir remains an enigma in the marine carbon cycle. The fact that DOC is significantly older than dissolved inorganic carbon at every depth in the ocean forms the basis of our current framing of the marine DOC cycle, where some component persists over multiple cycles of ocean mixing. As a result, 14C-depleted, aged DOC is hypothesized to be present as a uniform reservoir with a constant 14C signature and concentration throughout the water column. However, key requirements of this model, including direct observations of DOC with similar 14C signatures in the surface and deep ocean, have never been met. Despite decades of research, the distribution of Δ14C values in marine DOC remains a mystery. Here, we applied a thermal fractionation method to compare operationally defined refractory DOC (RDOC) from different depths in the North Pacific Ocean. We found that RDOC shares chemical characteristics (as recorded by OC bond strength) throughout the water column but does not share the same 14C signature. Our results support one part of the current paradigm{\textemdash}that RDOC is comprised of structurally related components throughout the ocean that form a {\textquotedblleft}background{\textquotedblright} reservoir. However, in contrast to the current paradigm, our results are consistent with a vertical concentration gradient and a vertical and inter-ocean Δ14C gradient for RDOC. The observed Δ14C gradient is compatible with the potential addition of pre-aged DOC to the upper ocean.},
	keywords = {marine dissolved organic matter, radiocarbon, ramped pyrolysis oxidation},
	issn = {1944-9224},
	doi = {10.1029/2022GB007603},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2022GB007603},
	author = {White, Margot E. and Nguyen, Tran B. and Koester, Irina and Lardie Gaylord, Mary C. and Beman, J. Michael and Smith, Kenneth L. and McNichol, Ann P. and Beaupr{\'e}, Steven R. and Aluwihare, Lihini I.}
}
@article {2760,
	title = {A late Holocene subfossil Atlantic white cedar tree-ring chronology from the northeastern United States},
	journal = {Quaternary Science Reviews},
	volume = {228},
	year = {2020},
	month = {Jan-01-2020},
	pages = {106104},
	abstract = {Tree-rings provide precise annually dated climate information, but their application can be limited by the relatively short lifespan of many trees. To overcome this limitation, tree-ring records can be extended over longer time periods by connecting living trees with older {\textquotedblleft}sub-fossil{\textquotedblright} trees, which can provide information on longer timescales throughout the Holocene. These long chronologies are proxy records of past climate, provide precise chronological information for extreme events, and give insight into the range of natural climate variability prior to the instrumental period. In the densely populated northeastern United States, few tree-ring records are longer than 500 years, and there are no millennial-length tree-ring chronologies for the region. Here, we use a combination of standard dendrochronological and radiocarbon techniques, including use of the 774 CE radiocarbon excursion, to generate an absolutely dated 2500 year-long tree ring record from living, archaeological, and subfossil Atlantic white cedar (Chamaecyparis thyoides) found in the coastal northeastern United States. Our chronology demonstrates the potential to develop multi-millennial Chamaecyparis thyoides tree-ring records to address previously unanswered questions regarding late Holocene hydroclimate, extreme events, and temperature variability in New England.},
	keywords = {coastal, Geomorphology, Holocene, North America, paleoclimatology, radiogenic isotopes, Tree-rings},
	issn = {02773791},
	doi = {10.1016/j.quascirev.2019.106104},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0277379119308108},
	author = {Pearl, Jessie K. and Anchukaitis, Kevin J. and Donnelly, Jeffrey P. and Pearson, Charlotte and Pederson, Neil and Lardie Gaylord, Mary C. and McNichol, Ann P. and Cook, Edward R. and Zimmermann, George L.}
}
