@article {jiang_comparing_2023,
	title = {Comparing the isotopic and molecular composition of dissolved organic carbon between the oligotrophic South China Sea and the adjacent North Pacific Ocean: Signals of biodegradation, conservative mixing, and terrestrial input},
	journal = {Marine Chemistry},
	volume = {257},
	year = {2023},
	month = {11/2023},
	pages = {104331},
	abstract = {The cycling of oceanic dissolved organic carbon (DOC) is a crucial component of the global carbon cycle, yet the identification of sources and the mechanisms of its molecular transformation remain poorly understood. This study compared the isotopic and molecular composition of DOC between the oligotrophic South China Sea (SCS) and the adjacent North Pacific Ocean (NPO), and traced both its allochthonous and autochthonous sources as well as its dynamic cycling processes. DOC was collected through solid-phase extraction (SPE) from water samples of both the SCS and NPO. Carbon content, isotopic ratios, and high-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) measurements revealed that SPE-DOC contained both labile and refractory fractions. According to our mass balance model, the labile fraction of SPE-DOC exhibited a decline from 11.5 to 12.6~μM in surface waters to a negligible concentration below 1000~m. Conversely, the refractory fraction of SPE-RDOC maintained a relatively consistent value, ranging from 12.7 to 19.0~μM across the entire water column. The vertical distribution patterns of the molecular composition and carbon isotopic ratios jointly indicated that the DOC distributions are shaped by distinct biological and physical processes within different biogeochemical realms of the water column. The production and transformation of the relatively labile DOC fractions were the dominant processes in the epipelagic and mesopelagic zones (upper 1000~m). The extent of diapycnal mixing between the SCS and NPO explained the different vertical distributions of refractory DOC molecules in the bathypelagic oceans. The molecular indices of polyphenol compounds, aromaticity, double bond saturation state, terrestrial mass peaks, and δ13C ratios of SPE-DOC indicated contributions from terrestrial sources, likely riverine input, in the SCS. This study sheds light on the molecular evidence of DOC sources, as well as their transformation and conservative mixing processes along the overturning circulation in marginal seas.},
	keywords = {carbon isotopes, dissolved organic carbon, FT-ICR-MS, North pacific ocean, radiocarbon, south china sea},
	issn = {0304-4203},
	doi = {10.1016/j.marchem.2023.104331},
	url = {https://www.sciencedirect.com/science/article/pii/S0304420323001275},
	author = {Jiang, Peng and Chen, Hongmei and Liu, Zhanfei and Li, Xiaolin}
}
@article {2627,
	title = {Late Pleistocene to Holocene productivity changes in the western equatorial Pacific (Sulu Sea, Philippines) from calcareous nannofossils},
	journal = {Marine Micropaleontology},
	volume = {143},
	year = {2018},
	month = {Jan-09-2018},
	pages = {1 - 11},
	abstract = {We present a new calcareous nannofossil paleoproductivity reconstruction of the southeastern margin of the Sulu Sea to understand how marine productivity varied through time in one of the major fishing grounds of the Philippine archipelago. The study is based on two sediment cores obtained from two different hydrographic locations in the western equatorial Pacific region: an upwelling region off Zamboanga Peninsula (U-GC12) and a non-upwelling area off Panay Island (NU-GC14), covering the past 18,000 years before present (B.P.). Calcareous nannofossil assemblages in the investigated areas were of low diversity and largely dominated by Gephyrocapsa oceanica and Florisphaera profwida, followed by small placolith-bearing taxa, Emiliania hwcleyi, small Gephyrocapsa, and Reticulofenestra minuta. Upwelling episodes off the Zamboanga Peninsula were recorded several times in the past as shown by an increase in the abundance of high productivity indicator species (G. oceanica, small Gephyrocapsa, E. hwcleyi) and of bulk sediment CaCO3 (\%), and a concomitant decline in the total organic carbon (TOC; \%). The high abundance of low surface water productivity species F. profunda and Umbellosphaera irregularis indicates a stratified water column with a deeper nutricline, probably caused by the reduced upwelling intensity. This condition was corroborated by the decrease in CaCO3 (\%) and an increase in TOC (\%). We propose that the modern day high productivity conditions off Zamboanga Peninsula started at 2500 years B.P., whereas the low productivity off Panay Island was recorded from 4000 years B.P., and persists to the present day. Evidence of the Younger Dryas (YD) event was recorded from 11,100 to 10,400 years B.P. in UGC12, synchronous to the YD event reported from other areas in the Northern Hemisphere, and in accordance with the timing in the Sulu Sea as reported from previous studies in this region. This event in the Sulu Sea is characterized by a decrease in total nannofossil abundance and estimated primary productivity, together with an increase in CaCO3 (\%) and a decrease in TOC (\%). We interpreted that dilution caused by the increase in precipitation experienced in the Southeast Asian region during the YD event could have led to the decline of the total calcareous nannofossils whereas the recorded increase in CaCO3 (\%) is attributed to the high abundance of planktonic foraminifera during this interval.},
	keywords = {arabian sea, EAST-ASIAN MONSOON, GLOBAL YOUNGER-DRYAS, indian-ocean, last deglaciation, OCEANIC PRIMARY PRODUCTION, south china sea, surface sediments, UPWELLING SYSTEM, YR BP},
	issn = {03778398},
	doi = {10.1016/j.marmicro.2018.07.001},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0377839816301219https://api.elsevier.com/content/article/PII:S0377839816301219?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0377839816301219?httpAccept=text/plain},
	author = {Tangunan, Deborah N. and Peleo-Alampay, Alyssa M.}
}
@article {1964,
	title = {Last deglaciation in the Okinawa Trough: Subtropical northwest Pacific link to Northern Hemisphere and tropical climate},
	journal = {Paleoceanography},
	volume = {20},
	year = {2005},
	note = {975ipTimes Cited:53
Cited References Count:55
},
	month = {Oct 7},
	abstract = {[1] Detailed deglacial and Holocene records of planktonic delta O-18 and Mg/Ca - based sea surface temperature (SST) from the Okinawa Trough suggest that at similar to 18 to 17 thousand years before present (kyr B. P.), late spring/ early summer SSTs were approximately 3 degrees C cooler than today, while surface waters were up to 1 practical salinity unit saltier. These conditions are consistent with a weaker influence of the summer East Asian Monsoon (EAM) than today. The timing of suborbital SST oscillations suggests a close link with abrupt changes in the EAM and North Atlantic climate. A tropical influence, however, may have resulted in subtle decoupling between the North Atlantic and the Okinawa Trough/EAM during the deglaciation. Okinawa Trough surface water trends in the Holocene are consistent with model simulations of an inland shift of intense EAM precipitation during the middle Holocene. Millennial-scale alternations between relatively warm, salty conditions and relatively cold, fresh conditions suggest varying influence of the Kuroshio during the Holocene.},
	keywords = {cal kyr bp, deep-ocean circulation, equatorial current, kuroshio current, late pleistocene, oxygen-isotope, planktonic-foraminifera, radiocarbon age calibration, south china sea, surface-water},
	isbn = {0883-8305},
	doi = {10.1029/2004PA001061},
	url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2\&amp;SrcAuth=Alerting\&amp;SrcApp=Alerting\&amp;DestApp=WOS\&amp;DestLinkType=FullRecord;UT=WOS:000232654500001},
	author = {Sun, Y. B. and Oppo, D. W. and Xiang, R. and Liu, W. G. and Gao, S.}
}
@article {2084,
	title = {East Asian monsoon forcing of suborbital variability in the Sulu Sea during Marine Isotope Stage 3: Link to Northern Hemisphere climate},
	journal = {Geochemistry Geophysics Geosystems},
	volume = {4},
	year = {2003},
	note = {631mwTimes Cited:41
Cited References Count:53
},
	month = {Jan 2},
	abstract = {[1] We have generated a new high-resolution record of variations in planktonic foraminiferal oxygen isotopes (delta(18)O) and Mg/Ca from a sediment core (IMAGES 97-2141) in the Sulu Sea located in the Philippine archipelago of western tropical Pacific. This record reveals distinct, suborbital-scale delta(18)O changes, most notably during Marine Isotope Stage 3 (MIS3) (similar to30,000 to 60,000 years B.P.). The amplitudes of these delta(18)O fluctuations (0.4 to 0.7parts per thousand) exceed that which can be attributed to sea level changes and must be due to changes in sea surface conditions. In the same interval, variations in planktonic foraminifera Mg/Ca suggest that suborbital surface ocean temperature variations of 1 to 1.5degreesC in the Sulu Sea were not in phase with delta(18)O. Combined, this evidence indicates that the MIS3 millennial delta(18)O events in the Sulu Sea were primarily the result of changes in surface water salinity, which today is directly related to the East Asian Monsoon (EAM) and its influence on the balance between surface water contributions from the South China Sea and Western Pacific Warm Pool (WPWP). Within dating uncertainties the MIS3 Sulu Sea delta(18)O suborbital variability indicates that times of fresher surface conditions in the Sulu Sea coincide with similar conditions in the WPWP [Stott et al., 2002] and also with intensifications of the summer EAM as recorded in the U-Th dated Chinese (Hulu Cave) speleothem delta(18)O record [Wang et al., 2001] and thus by inference with interstadials in the Greenland Ice core records. Combined, these results indicate that pronounced suborbital variability in the summer EAM and Intertropical Convergence Zone (ITCZ) during MIS3 was tightly coupled with climate conditions in the northern high latitudes.},
	keywords = {1620 global change : climate dynamics (3309), 4267 oceanography : general : paleoceanography, dissolution, equatorial pacific, eurasian snow cover, isotope stage 3, last glacial period, late pleistocene, Mg/Ca, millennial-scale climate change, oxygen isotopes, paleoceanography, planktonic-foraminifera, records, se asian monsoon, south china sea, summer monsoon, surface temperature-variations},
	isbn = {1525-2027},
	doi = {10.1029/2002GC000390},
	author = {Dannenmann, S. and Linsley, B. K. and Oppo, D. W. and Rosenthal, Y. and Beaufort, L.}
}
