@article {2508,
	title = {Export of submicron particulate organic matter to mesopelagic depth in an oligotrophic gyre},
	journal = {Proceedings of the National Academy of Sciences},
	volume = {110},
	year = {2013},
	month = {Jun-07-2015},
	pages = {12565 - 12570},
	abstract = {Sixty percent of the world ocean by area is contained in oligotrophic gyres [Longhurst A (1995) Prog Oceanog 36:77-16], the biomass of which is dominated by picophytoplankton, including cyanobacteria and picoeukaryotic algae, as well as picoheterotrophs. Despite their recognized importance in carbon cycling in the surface ocean, the role of small cells and their detrital remains in the transfer of particulate organic matter (POM) to the deep ocean remains disputed. Because oligotrophic marine conditions are projected to expand under current climate trends, a better understanding of the role of small particles in the global carbon cycle is a timely goal. Here we use the lipid profiles, radiocarbon, and stable carbon isotopic signatures of lipids from the North Pacific Subtropical Gyre to show that in the surface ocean, lipids from submicron POM (here called extra-small POM) are distinct from larger classes of suspended POM. Remarkably, this distinct extra-small POM signature dominates the total lipids collected at mesopelagic depth, suggesting that the lipid component of mesopelagic POM primarily contains the exported remains of small particles. Transfer of submicron material to mesopelagic depths in this location is consistent with model results that claim the biological origin of exported carbon should be proportional to the distribution of cell types in the surface community, irrespective of cell size [Richardson TL, Jackson GA (2007) Science 315:838-840]. Our data suggest that the submicron component of exported POM is an important contributor to the global biological pump, especially in oligotrophic waters. 
},
	keywords = {Biogeochemistry, biomarkers, carbon isotopes, Oceanography},
	issn = {0027-8424},
	doi = {10.1073/pnas.1217514110},
	url = {http://www.pnas.org/cgi/doi/10.1073/pnas.1217514110https://syndication.highwire.org/content/doi/10.1073/pnas.1217514110},
	author = {Close, H. G. and Shah, S. R. and Ingalls, A. E. and Diefendorf, A. F. and Brodie, E. L. and Hansman, R. L. and Freeman, K. H. and Aluwihare, L. I. and Pearson, A.}
}
@article {180,
	title = {Holocene Southern Ocean surface temperature variability west of the Antarctic Peninsula},
	journal = {Nature},
	volume = {470},
	year = {2011},
	note = {id: 2053; PT: J; UT: WOS:000287144200042},
	pages = {250-254},
	abstract = {The disintegration of ice shelves, reduced sea-ice and glacier extent, and shifting ecological zones observed around Antarctica(1,2) highlight the impact of recent atmospheric(3) and oceanic warming(4) on the cryosphere. Observations(1,2) and models(5,6) suggest that oceanic and atmospheric temperature variations at Antarctica{\textquoteright}s margins affect global cryosphere stability, ocean circulation, sea levels and carbon cycling. In particular, recent climate changes on the Antarctic Peninsula have been dramatic, yet the Holocene climate variability of this region is largely unknown, limiting our ability to evaluate ongoing changes within the context of historical variability and underlying forcing mechanisms. Here we show that surface ocean temperatures at the continental margin of the western Antarctic Peninsula cooled by 3-4 degrees C over the past 12,000 years, tracking the Holocene decline of local (65 degrees S) spring insolation. Our results, based on TEX(86) sea surface temperature (SST) proxy evidence from a marine sediment core, indicate the importance of regional summer duration as a driver of Antarctic seasonal sea-ice fluctuations(7). On millennial timescales, abrupt SST fluctuations of 2-4 degrees C coincide with globally recognized climate variability(8). Similarities between our SSTs, Southern Hemisphere westerly wind reconstructions(9) and El Nino/Southern Oscillation variability(10) indicate that present climate teleconnections between the tropical Pacific Ocean and the western Antarctic Peninsula(11) strengthened late in the Holocene epoch. We conclude that during the Holocene, Southern Ocean temperatures at the western Antarctic Peninsula margin were tied to changes in the position of the westerlies, which have a critical role in global carbon cycling(9,12).},
	issn = {0028-0836},
	doi = {10.1038/nature09751},
	author = {Shevenell, A. E. and Ingalls, A. E. and Domack, E. W. and Kelly, C.}
}
@article {1942,
	title = {Quantifying archaeal community autotrophy in the mesopelogic ocean using natural radiocarbon},
	journal = {Proc. Natl. Acad. Sci. USA},
	volume = {103},
	year = {2006},
	note = {id: 502},
	month = {2006},
	pages = {6442-6447},
	author = {Ingalls, A. E. and Shah, S. R. and Hansman, R. L. and Aluwihare, L. I. and Santos, G. M. and Druffel, E. R. M. and Pearson, A.}
}
@article {1990,
	title = {Ten years of compound-specific radiocarbon analysis},
	journal = {Oceanography},
	volume = {18},
	year = {2005},
	note = {id: 504},
	month = {2005},
	pages = {18-31},
	author = {Ingalls, A. E. and Pearson, A.}
}
@article {577,
	title = {Radiocarbon dating of diatom-bound organic compounds},
	journal = {Marine Chemistry},
	volume = {92},
	year = {2004},
	note = {882iaTimes Cited:34Cited References Count:33},
	month = {Dec 1},
	pages = {91-105},
	abstract = {Here we present a new method for obtaining radiocarbon dates for the organic compounds intrinsic to diatom frustules. This method will improve age models for sediment cores that lack calcium carbonate and improve current interpretations of diatom-based paleoproxies. In preparation for radiocarbon dating by Accelerator Mass Spectrometry, compounds intrinsic to diatom frustules are released from their opal matrix by dissolution in HF and then purified using preparative liquid chromatography-mass spectrometry (LC-MS). The method was applied to one sample from each of three cores (NBP9802 Station 7 GC2; TN057-13 PC4; Ell-2) and a plankton tow (CRS 746, FOODBANCS) collected in the Southern Ocean. In each sample, radiocarbon ages of diatom-bound organic compounds differed from those obtained from foraminiferal CaCO3. Agreement between the foraminifera and compound-specific date was best in cores Ell-2 and TN057-13. In contrast, compound-specific C-14 ages obtained from NBP9802 differed substantially from those measured for foraminiferal CaCO3. The influence of background contamination was assessed throughout all stages of the method and cannot be responsible for the discrepancy observed. Possible reasons for the disagreement between the ages of foraminifera and diatom-bound compounds are discussed in the context of sediment dynamics. These preliminary results suggest that our diatom-based dating method represents a major step forward in our ability interpret sediment records in the Southern Ocean and therefore our understanding of the role of the Southern Ocean in past climate. (C) 2004 Elsevier B.V. All rights reserved.},
	issn = {0304-4203},
	doi = {10.1016/j.marchem.2004.06.019},
	author = {Ingalls, A. E. and Anderson, R. F. and Pearson, A.}
}
