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Xingchen Wang*, Yuwei Wang, Alexandra Auderset, Daniel Sigman, Haojia Ren, Alfredo Martínez-García, Gerald Haug, Zhan Su, Yige Zhang, Birger Rasmussen, Alex Sessions, Woodward Fischer (2022), Oceanic nutrient rise and the late Miocene inception of Pacific oxygen-deficient zones, PNAS, 119 (45) e2204986119

Ting-Yu Chen, Chia-Li Chen, Yi-Chi Chen, Charles C.-K. Chou, Haojia Ren*, and Hui-Ming Hung* (2022), Source Apportionment and Evolution of N-containing Aerosols at a Rural Cloud Forest in Taiwan by Isotope Analysis. Atmos. Chem. Phys. Discuss. 22, 13001–13012, 2022

Patrick Martin*, Molly A. Moynihan, Shuang Chen, Oon Yee Woo, Yongli Zhou, Robert S. Nichols, Kristy Y.W. Chang, Ashleen S.Y. Tan, Ying-Hsuan Chen, Haojia Ren, Mengli Chen (2022). Monsoon-driven biogeochemical dynamics in an equatorial shelf sea: Time-series observations in the Singapore Strait, Estuarine, Coastal and Shelf Science, 270, 107855, ISSN 0272-7714, 

Yuhao Dai*, Jimin Yu, Haojia Ren, and Xuan Ji (2022). Deglacial Subantarctic CO2 outgassing driven by a weakened solubility pump. Nature Communication, 13, 5193.


J. R. Farmer, J. E. Hertzberg, D. Cardinal, S. Fietz, K. Hendry, S. L. Jaccard, A. Paytan, P. A. Rafter, H. Ren, C. J. Somes, J. N. Sutton, GEOTRACESPAGES Biological Productivity Working Group Members (2021).  Assessment of C, N, and Si isotopes as tracers of past ocean nutrient and carbon cycling. Global Biogeochemical Cycles, 35, e2020GB006775.

Horner, T. J.,  Little, S. H.,  Conway, T. M.,  Farmer, J. R.,  Hertzberg, J. E.,  Janssen, D. J., GEOTRACES–PAGES Biological Productivity Working Group Members (2021). Bioactive trace metals and their isotopes as paleoproductivity proxies: An assessment using GEOTRACES-era data. Global Biogeochemical Cycles,  35, e2020GB006814.

Anja S. Studer, Figen Mekik, Haojia Ren, Sergey Oleynik, Alfredo Martínez-García, Gerald H. Haug, Daniel M. Sigman (2021). Foraminifera-bound nitrogen isotope evidence for similar rates of water column denitrification in the eastern equatorial Pacific during the last ice age and the Holocene, Paleoceanography and Paleoclimatology, 36, e2020PA004063.

Daniel M. Sigman, François Fripiat, Anja S. Studer, Preston C. Kemeny, Alfredo Martínez-García, Mathis P. Hain, Xuyuan Ai, Xingchen Wang, Haojia Ren, Gerald H. Haug (2021). The Southern Ocean during the ice ages: A review of the Antarctic surface isolation hypothesis, with comparison to the North Pacific, Quaternary Science Reviews, 254, 106732. 


Run Zhang*, Xingchen T. Wang, Haojia Ren, Jie Huang, Min Chen, and Daniel M. Sigman (2020), Dissolved organic nitrogen cycling in the South China Sea, Global Biogeochemical Cycles 34, e2020GB006551.

Sandi M. Smart*, Sarah E. Fawcett, Haojia Ren, Ralf Schiebel, Emily M. Tompkins, Alfredo Martínez‐García, Luca Stirnimann, Alakendra Roychoudhury, Gerald H. Haug, Daniel M. Sigman (2020).  The nitrogen isotopic composition of tissue and shell‐bound organic matter of planktic foraminifera in Southern Ocean surface waters. Geochemistry, Geophysics, Geosystems, 21, e2019GC008440.

Charlotte LeKieffre*, Howard J. Spero, Jennifer S. Fehrenbacher, Ann D. Russell, Haojia Ren, Emmanuelle Geslin, and Anders Meibom (2020). Ammonium is the preferred source of nitrogen for planktonic foraminifer and their dinoflagellate symbionts. Proc. R. Soc. B. 287: 20200620.



Jimin Yu*, L Menviel, ZD Jin, DJR Thornalley, GL Foster, EJ Rohling, IN McCave, JF McManus, Y Dai, H Ren, F He, F Zhang, PJ Chen, AP Roberts (2019) More efficient North Atlantic carbon pump during the Last Glacial Maximum. Nature Communications, 10 (1), doi:10.1038/s41467-019-10028-z.

Emma R. Kast*, Daniel A. Stolper, Alexandra Auderset, John A. Higgins, Haojia Ren, Xingchen T. Wang, Alfredo Martínez-García, Gerald H. Haug, Daniel M. Sigman (2019), Nitrogen isotope evidence for expanded ocean suboxia in the early Cenozoic, Science, 364, 6438, 386-389, DOI: 10.1126/science.aau5784. 


Ralf Schiebel, Sandi M. Smart, Anna Jentzen, Lukas Jonkers, Raphaël Morard, Julie Meilland, Elisabeth Michel, Helen K. Coxall, Pincelli M. Hull, Thibault de Garidel-Thoron, Tracy Aze, Frédéric Quillévéré, Haojia Ren, Daniel M. Sigman, Hubert B. Vonhof, Alfredo Martínez-García, Michal Kučera, Jelle Bijma, Howard J. Spero, Gerald H. Haug (2018), Advances in planktonic foraminifer research: New perspectives for paleoceanography, Revue de Micropaléontologie, 61, 3–4, 113-138, ISSN 0035-1598,

Xingchen T. Wang*, Anne L. Cohen, Victoria Luu, Haojia Ren, Zhan Su, Gerald H. Haug, and Daniel M. Sigman (2018), Natural forcing of the North Atlantic nitrogen cycle in the Anthropocene, PNAS, doi/10.1073/pnas.1801049115. Download 

Sandi M. Smart*, Haojia Ren, Sarah E. Fawcett, Ralf Schiebel, Maureen Conte, Patrick A. Rafter, Karen K. Ellis, Mira A. Weigand, Sergey Oleynik, Gerald H.Haug, Daniel M.Sigman (2018), Ground-truthing the planktic foraminifer-bound nitrogen isotope paleo-proxy in the Sargasso Sea, Geochimica et Cosmochimica Acta, 235, 463-482.

Tingting Wang, Ana Christina Ravelo, Haojia Ren, Haowen Dang, Haiyan Jin, Jingjing Liu, Zhimin Jian* (2018), Nitrogen isotope variations in the northern South China Sea since marine isotopic stage 3: reconstructed from foraminifera-bound and bulk sedimentary nitrogen, Paleoceanography and Paleoclimatology, 33.

Thomas DeCarlo*, Haojia Ren, Gabriela Farfan (2018), The Origin and Role of Organic Matrix in Coral Calcification: Insights From Comparing Coral Skeleton and Abiogenic Aragonite, Frontiers in Marine Science, 5:170. doi: 10.3389/fmars.2018.00170. 


Haojia Ren*, Daniel M. Sigman, Alfredo Martinez-Garcia, Robert F. Anderson, Min-Te Chen, Ana Christina Ravelo, Marietta Straub, George T.F. Wong, Gerald Haug (2017), Impact of glacial/interglacial sea level change on the ocean nitrogen cycle, PNAS, 114(33), 6759-6766. Download

Haojia Ren*, Yi-Chi Chen, Xingchen T. Wang, George T.F. Wong, Anne L. Cohen, Thomas M. DeCarlo, Mira A. Weigand, Horng-Sheng Mii, Daniel M. Sigman (2017), 21st Century Rise in Anthropogenic Nitrogen Deposition on a Remote Coral Reef, Science, 356, 749-752. Download  Highlighted by Science   In the news

Yige Zhang*, Mark Pagani, Jorijintje Henderiks, Haojia Ren (2017), A long history of equatorial deep-water upwelling in the Pacific Ocean, Earth and Planetary Science Letters, 467: 1-9. Download


Xingchen T. Wang*, Daniel M. Sigman, Anne L. Cohen, Daniel J. Sinclair, Robert M. Sherrell, Kim M. Cobb, Dirk V. Erler, Jaroslaw Stolarski, Marcelo V. Kitahara, Haojia Ren (2016), Influence of open ocean nitrogen supply on the skeletal of modern shallow-water scleractinian corals, Earth and Planetary Science Letters, 441, 125-132. Download

Kassandra M. Costa*, Jerry F. McManus, Robert F. Anderson, Haojia Ren, Daniel M. Sigman, Gisela Winckler, M. Q. Fleisher, F. Marcantonio, A. C. Ravelo (2016), No iron fertilization in the Equatorial Pacific during the Last Ice Age, Nature, 529, 519-522. Download


Haojia Ren*, Anja S. Studer, Sascha Serno, Daniel M. Sigman, Gisela Winckler, Robert F. Anderson, Sergey Oleynik, Rainter Gersonde, and Gerald H. Haug (2015), Glacial-to-interglacial changes in nitrate supply and consumption in the subarctic North Pacific from microfossil-bound N isotopes at two trophic levels, Paleoceanography, 30, 1217–1232. Download

Sascha Serno*, Gisela Winckler, Robert F. Anderson, E. Maier, Haojia Ren, Rainer Gersonde, and Gerald H. Haug (2015), Comparing dust flux records from the Subarctic North Pacific and Greenland: Implications for atmospheric transport to Greenland and for the application of dust as a chronostratigraphic tool, Paleoceanography, 30. Download


Xingchen T. Wang*, Daniel M. Sigman, Anne L. Cohen, Daniel J. Sinclair, Robert M. Sherrell, Mira A. Weigand, Dirk V. Erler, and Haojia Ren (2014), Isotopic composition of skeleton-bound organic nitrogen in reef-building symbiotic corals: A new method and proxy evaluation at Bermuda, Geochimica et Cosmochimica Acta, 148, 179-190. Download

Sascha Serno*, Gisela Winckler, Robert F. Anderson, Christopher T. Hayes, Haojia Ren, Rainer Gersonde, Gerald H. Haug (2014), Using the natural spatial pattern of marine productivity in the Subarctic North Pacific to evaluate paleoproductivity proxies, Paleoceanography, 29(5), 438-453. Download

Xingchen T. Wang*, Maria G. Prokopenko, Daniel M. Sigman, Jess F. Adkins, Laura F. Robinson, Haojia Ren, Sergey Oleynik, Branwen Williams, Gerald H. Haug (2014), Isotopic composition of carbonate-bound organic nitrogen in deep-sea scleractinian corals: A new window into past biogeochemical change, Earth and Planetary Science Letters, 400, 243-250. Download

Sascha Serno*, Gisela Winckler, Robert F. Anderson, Christopher T. Hayes, David McGee, Bjorn Machalett, Haojia Ren, Susanne M. Straub, Rainer Gersonde, Gerald H. Haug (2014), Eolian dust input to the Subarctic North Pacific, Earth and Planetary Science Letters, 387, 252-263. Download

Alfredo Martinez-Garcia*, Daniel M. Sigman, Haojia Ren, Robert F. Anderson, Marietta Straub, David A. Hodell, Samuel L. Jaccard, Timothy I. Eglinton, Gerald H. Haug (2014), Iron fertilization of the Subantarctic Ocean during the last ice age, Science, 343, 6177. Download


Marietta Straub*, Daniel M. Sigman, Haojia Ren, Alfredo Martinez-Garcia, A. Nele Meckler, and Gerald H. Haug (2013), Changes in North Atlantic nitrogen fixation controlled by ocean circulation, Nature, 501, 200-203. Download

Haojia Ren*, Brigitte G. Brunelle, Daniel M. Sigman, and Rebecca S. Robinson (2013), Diagenetic aluminum uptake into diatom frustules and the preservation of diatom-bound organic nitrogen, Marine Chemistry, 155, 92-101. Download

Marietta Straub*, Marissa Tremblay, Daniel M. Sigman, Anja S. Studer, Haojia Ren, Satish Myneni, J. Robert Toggweiler, and Gerald H. Haug (2013), Nutrient conditions in the subpolar North Atlantic during the last glacial period reconstructed from foraminifera-bound nitrogen isotopes, Paleoceanography, 28(1), 79-90. Download


Haojia Ren*, Daniel M. Sigman, Robert C. Thunell, and Maria G. Prokopenko (2012), Nitrogen isotopic composition of planktonic foraminifera from the modern ocean and recent sediments, Limnology and Oceanography, 57(4), 1011-1024. Download

Haojia Ren*, Daniel M. Sigman, Min-Te Chen, and Shuh-ji Kao (2012), Elevated Foraminifera-bound Nitrogen Isotopic Composition During the Last Ice Age in the South China Sea and Its Global and Regional Implications, Global Biogeochemical Cycles, 26, GB1031, doi:10.1029/2010GB004020. Download

Shuh-Ji Kao*, Jin-Yu Yang, Kon-Kee Liu, Minhan Dai, Wen-Chen Chou, Hui-Ling Lin, and Haojia Ren (2012), Isotope constraints on particulate nitrogen dynamics in the upper water column of the oligotrophic South China Sea, Global Biogeochemical Cycles, 26, GB2033, doi:10.1029/2011GB004091.


Anna Nele Meckler*, Haoija Ren, Daniel M. Sigman, Birgit Plessen, Schubert, and Gerald H. Haug (2011), Deglacial nitrogen isotope changes in the Gulf of Mexico: Evidence from bulk sedimentary and foraminifera-bound nitrogen in Orca Basin sediments, Paleoceanography, 26, PA4216, doi:10.1029/2011PA002156.


Haojia Ren*, Daniel M. Sigman, Anna Nele Meckler, Birgit Plessen, and Rebecca S. Robinson, Yair Rosenthal, and Gerald H. Haug (2009), Foraminiferal isotope evidence of reduced nitrogen fixation in the Ice Age Atlantic Ocean, Science, 323, 244. Download

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