Hostname: page-component-586b7cd67f-t7czq Total loading time: 0 Render date: 2024-11-26T10:16:22.509Z Has data issue: false hasContentIssue false
  • English
  • Français

Causes and climatic influence of centennial-scale denitrification variability in the southeastern Arabian Sea since the last glacial period

Published online by Cambridge University Press:  29 January 2021

Sidhesh Nagoji  and
Manish Tiwari Open the ORCID record for Manish Tiwari [Opens in a new window]
Sidhesh Nagoji
Affiliation:
National Centre for Polar and Ocean Research, Ministry of Earth Sciences, Vasco-da-Gama, Goa403804, India
Manish Tiwari*
Affiliation:
National Centre for Polar and Ocean Research, Ministry of Earth Sciences, Vasco-da-Gama, Goa403804, India
*
*Corresponding author e-mail address: [email protected](M. Tiwari)
Get access Rights & Permissions [Opens in a new window]

Abstract

Denitrification occurring in the oxygen minimum zone of the Arabian Sea produces nitrous oxide, a powerful greenhouse gas. Therefore, it is important to understand the mechanisms controlling denitrification's intensity and evaluate its influence on the global climate at various timescales. We studied multiple geochemical and isotopic proxies in a sediment core from the southeastern Arabian Sea (SEAS) at a high (centennial-scale) resolution. We find that since the last glacial period, both the ventilation and the productivity caused by the South Asian summer monsoon played a major role in controlling the denitrification variability in SEAS. During the Last Glacial Maximum (LGM) and since the Holocene, denitrification increased in SEAS despite reduced monsoon-induced productivity. During the LGM, weakened thermohaline circulation resulted in reduced ventilation of the intermediate waters of SEAS, causing increased denitrification. During the Holocene, the increase in denitrification is caused by an enhanced inflow of oxygen-depleted Red Sea and Persian Gulf waters into the intermediate depth of SEAS owing to a rising sea level that prohibited ventilation by the Antarctic Intermediate Water. We further find millennial-scale synchronicity between denitrification in SEAS, global monsoons, and the North Atlantic climate, implying systematic linkages via greenhouse gases abundance.

Keywords

QuaternaryPaleoceanographyPaleoclimatologyGlobalStable IsotopesMonsoonDenitrificationArabian SeaTeleconnectionVentilation
Type
Research Article
Information
Quaternary Research , Volume 101 , May 2021 , pp. 156 - 168
Check for updates
Copyright
Copyright © University of Washington. Published by Cambridge University Press, 2021

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES CITED

Agnihotri, R., Bhattacharya, S.K., Sarin, M.M., Somayajulu, B.L.K., 2003. Changes in surface productivity and subsurface denitrification during the Holocene: a multiproxy study from the eastern Arabian Sea. The Holocene 13, 701–713.CrossRefGoogle Scholar
Altabet, M.A., Francois, R., Murray, D.W., Prell, W.L., 1995. Climate related variations in denitrification in the Arabian Sea from sediment 15N/14N ratios. Nature 373, 506–509.CrossRefGoogle Scholar
Altabet, M.A., Higginson, M.J., Murray, D.W., 2002. The effect of millennial-scale changes in Arabian Sea denitrification on atmospheric CO2. Nature 415, 159–162.CrossRefGoogle ScholarPubMed
Altabet, M.A., Murray, D.W., Prell, W.L., 1999. Climatically linked oscillations in Arabian Sea denitrification over the past 1 m.y.: implications for the marine N cycle. Paleoceanography 14, 732–743.CrossRefGoogle Scholar
Anand, P., Kroon, D., Singh, A.D., Ganeshram, R.S., Ganssen, G., Elderfield, H., 2008. Coupled sea surface temperature-seawater δ18O reconstructions in the Arabian Sea at the millennial scale for the last 35 ka. Paleoceanography 23, 4207.CrossRefGoogle Scholar
Anderson, D.M., Baulcomb, C.K., Duvivier, A.K., Gupta, A.K., 2010. Indian summer monsoon during the last two millennia. Journal of Quaternary Science 25, 911–917.CrossRefGoogle Scholar
Anil Kumar, A., Rao, V.P., Patil, S.K., Kessarkar, P.M., Thamban, M., 2005. Rock magnetic records of the sediments of the eastern Arabian Sea: evidence for late Quaternary climatic change. Marine Geology 220, 59–82.CrossRefGoogle Scholar
Banse, , 1987. Seasonality in phytoplankton chlorophyll in the central and northern Arabian Sea. Deep Sea Research I 34, 713–723.CrossRefGoogle Scholar
Banse, K., Naqvi, S.W. A., Narvekar, P.V., Postel, J.R., Jayakumar, D.A., 2014. Oxygen minimum zone of the open Arabian Sea: variability of oxygen and nitrite from daily to decadal timescales. Biogeosciences 11, 2237–2261.CrossRefGoogle Scholar
Bé, A.W.H., Tolderlund, D.S., 1971. Distribution and ecology of living planktonic foraminifera in surface waters of the Atlantic and Indian Oceans. In: Funnell, B.M., Riedel, W.R. (Eds.), The Micropaleontology of Oceans. Cambridge University Press, Cambridge, U.K., pp. 105–149.Google Scholar
Bhattathiri, P.M.A., Pant, A., Sawant, S., Gauns, M., Matondakar, S.G.P., Mohanraju, R., 1996. Phytoplankton production and chlorophyll distribution in the eastern and central Arabian Sea in 1994–1995. Current Science 71, 857–862.Google Scholar
Blunier, T., Brook, E.J., 2001. Timing of millennial-scale climate change in Antarctica and Greenland during the last glacial period. Science 291, 109–112.CrossRefGoogle ScholarPubMed
Brandes, J.A., Devol, A.H., 2002. A global marine-fixed nitrogen isotopic budget: implications for Holocene nitrogen cycling. Global Biogeochemical Cycles 16, 1–14.CrossRefGoogle Scholar
Brandes, J.A., Devol, A.H., Yoshinari, T., Jayakumar, D.A., Naqvi, S.W.A., 1998. Isotopic composition of nitrate in the central Arabian Sea and eastern tropical North Pacific: a tracer for mixing and nitrogen cycles. Limnology and Oceanography 43, 1680–1689.CrossRefGoogle Scholar
Brodie, C.R., Casford, J.S.L., Lloyd, J.M., Leng, M.J., Heaton, T.H.E., Kendrick, C.P., Zong, Y.Q., 2011. Evidence for bias in C/N, δ13C and δ15N values of bulk organic matter, and on environmental interpretation, from a lake sedimentary sequence by pre-analysis acid treatment methods. Quaternary Science Review 30, 3076–3087.CrossRefGoogle Scholar
Broecker, W.S., Peteet, D.M., Rind, D., 1985. Does the ocean- atmosphere system have more than one mode of operation? Nature 315, 21–26.CrossRefGoogle Scholar
Brunner, B., Contreras, S., Lehmann, M.F., Matantseva, O., Rollog, M., Kalvelage, T., Klockgether, G., et al. ., 2013. Nitrogen isotope effects induced by anammox bacteria. Proceedings of the National Academy of Sciences 110, 18994–18999.CrossRefGoogle ScholarPubMed
Butzin, M., Prange, M., Lohmann, G., 2005. Radiocarbon simulations for the glacial ocean: the effects of wind stress, southern ocean sea ice and Heinrich events. Earth Planetary Science Letters 235, 45–61.CrossRefGoogle Scholar
Calvert, S.A.E., Pedersen, T.F., 1993. Geochemistry of recent oxic and anoxic sediments: implications for the geological record. Marine Geology 113, 67–88.CrossRefGoogle Scholar
Cao, L., Fairbanks, R.G., Mortlock, R.A., Risk, M.J., 2007. Radiocarbon reservoir age of high latitude North Atlantic surface water during the last deglacial. Quaternary Science Review 26, 732–742.CrossRefGoogle Scholar
Capone, D.G., Subramaniam, A., Montoya, J.P., Voss, M., Humborg, C., Johansen, A.M., Siefert, R.L., Carpenter, E.J., 1998. An extensive bloom of the N2-fixing cyanobacterium Trichodesmium erythraeum in the central Arabian Sea. Marine Ecology Progress 172, 281–292.CrossRefGoogle Scholar
Charles, C.D., Fairbanks, R.G., 1992. Evidence from southern ocean sediments for the effect of North Atlantic deep water flux on climate. Nature 355, 416–419.CrossRefGoogle Scholar
Cheng, H.R., Edwards, L., Sinha, A., Spötl, C., Yi, L., Chen, S., Kelly, M., et al. , 2016. The Asian monsoon over the past 640,000 years and ice age terminations. Nature 534, 640–646.CrossRefGoogle ScholarPubMed
Codispoti, L.A., Brandes, J.A., Christensen, J.P., Devol, A.H., Naqvi, S.W.A., Paerl, H.W., Yoshinari, T., 2001. The oceanic fixed nitrogen and nitrous oxide budgets: moving targets as we enter the anthropocene? Scientia Marina 65, 85–105.CrossRefGoogle Scholar
Conan, S.M.H., Brummer, G.J., 2000. Fluxes of planktonic foraminifera in response to monsoonal upwelling on the Somalia Basin margin. Deep Sea Research Part II 47, 2207–2227.CrossRefGoogle Scholar
Dahl, K.A., Oppo, D.W., 2006. Sea surface temperature pattern reconstructions in the Arabian Sea. Paleoceanography 21, 1014.CrossRefGoogle Scholar
Deplazes, G., Lückge, A., Stuut, J.B.W., Pätzold, J., Kuhlmann, H., Husson, D., Fant, M., Haug, G.H., 2014. Weakening and strengthening of the Indian monsoon during Heinrich events and Dansgaard-Oeschger oscillations. Paleoceanography 29, 99–114.CrossRefGoogle Scholar
Farquhar, G.D., Ehleringer, J.R., Hubick, K.T., 1989. Carbon isotope discrimination and photosynthesis. Annual Review of Plant Physiology and Plant Molecular Biology 40, 503–537.CrossRefGoogle Scholar
Flückiger, J., Blunier, T., Stauffer, B., Chappellaz, J., Spahni, R., Kawamura, K., Schwander, J., Stocker, T.F., Dahl-Jensen, D., 2004. N2O and CH4 variations during the last glacial epoch: insight into global processes. Global Biogeochemical Cycles 18, 1020.CrossRefGoogle Scholar
Fontugne, M.R., Duplessy, J.C., 1986. Variations of the monsoon regime during the upper Quaternary: evidence from carbon isotopic record of organic matter in North Indian Ocean sediment cores. Palaeogeography, Palaeoclimatology, Palaeoecology 56, 69–88.CrossRefGoogle Scholar
Galbraith, E.D., Kienast, M., Pedersen, T.F., Calvert, S.E., 2004. Glacial-interglacial modulation of the marine nitrogen cycle by high-latitude O2 supply to the global thermocline. Paleoceanography 19, 4007.CrossRefGoogle Scholar
Ganeshram, R.S., Pedersen, T.F., Calvert, S.E., McNeil, G.W., 2000. Glacial-interglacial variability in denitrification in the world's oceans: causes and consequences. Paleoceanography 15, 361–376.CrossRefGoogle Scholar
Ganeshram, R.S., Pedersen, T.F., Calvert, S.E., Murray, J.W., 1995. Large changes in oceanic nutrient inventories from glacial to interglacial periods. Nature 376, 755–758.CrossRefGoogle Scholar
Ganeshram, R.S., Pederson, T.F., Calvert, S.E., Francois, R., 2002. Reducing nitrogen fixation in the glacial oceans inferred from changes in marine nitrogen and phosphate. Nature 415, 156–159.CrossRefGoogle Scholar
Gaye-Haake, B., Lahajnar, N., Emeis, K.-C., Unger, D., Rixen, T., Suthhof, A., Ramaswamy, V., et al. , 2005. Stable nitrogen isotopic ratios of sinking particles and sediments from the northern Indian Ocean. Marine Chemistry 96, 243–255.CrossRefGoogle Scholar
Goswami, B.N., Venugopal, V., Sengupta, D., Madhosoodanan, M.S., Zavier, P.K., 2006. Increasing trend of extreme rain events over India in a warming environment. Science 314, 1442–1445.CrossRefGoogle Scholar
Grinsted, A., Moore, J.C., Jevrejeva, S., 2004. Application of the cross wavelet transform and wavelet coherence to geophysical time series. Nonlinear Processes in Geophysics 11, 561–566.CrossRefGoogle Scholar
Gruber, N., Sarmiento, J.L., 2002. Large-scale biogeochemical-physical interactions in elemental cycles. In: Robinson, A.R., McCarthy, J.J., Rothschild, B.J. (Eds.), The Sea. Vol. 12, Biological-Physical Interactions in the Sea. John Wiley and Sons Inc., New York, pp. 337–399.Google Scholar
Hodell, D.A., Anselmetti, F.S., Ariztegui, D., Brenner, M., Curtis, J.H., Gilli, A., Grzesik, D.A., et al. , 2008. An 85-ka record of climate change in lowland Central America. Quaternary Science Reviews 27, 1152–1165.CrossRefGoogle Scholar
Howell, E.A., Dioney, S.C., Fine, R.A., Olson, D.B., 1997. Geochemical estimates of denitrification in the Arabian Sea and the Bay of Bengal during WOCE. Geophysical Research Letters 24, 2549–2552.CrossRefGoogle Scholar
Ivanochko, T.S., Ganeshram, R.S., Brummer, G.J.A., Ganssen, G., Jung, S.J.A., Moreton, S.G., Kroon, D., 2005. Variations in tropical convection as an amplifier of global climate change at the millennial scale. Earth and Planetary Science Letters 235, 302–314.CrossRefGoogle Scholar
Jung, S., Kroon, D., Ganssen, G., Peeters, F., 2009. Enhanced Arabian Sea intermediate water flow during glacial North Atlantic cold phases. Earth and Planetary Science Letters 280, 220–228.CrossRefGoogle Scholar
Kessarkar, P.M., Rao, V.P., Naqvi, S.W.A., Karapurkar, S.G., 2013. Variation in the Indian summer monsoon intensity during the Bolling-Allerod and Holocene. Paleoceanography 28, 413–425.CrossRefGoogle Scholar
Kobayashi, K., Makabe, A., Yano, M., Oshiki, M., Kindaichi, T., Casciotti, K.L., Okabe, S., 2019. Dual nitrogen and oxygen isotope fractionation during anaerobic ammonium oxidation by anammox bacteria. The ISME Journal 13, 2426–2436.CrossRefGoogle ScholarPubMed
Kroon, D., 1988. The planktic δ13C record, upwelling and climate. In: Brummer, G.J.A., Kroon, D. (Eds.), Planktonic Foraminifers as Tracers of Ocean-Climate History: Ontogeny, Relationships and Preservation of Modern Species and Stable Isotopes, Phenotypes and Assemblage Distribution in Different Water Masses. Free University Press, Amsterdam, pp. 335–346.Google Scholar
Kudrass, H.R., Hofmann, A., Doose, H., Emeis, K., Erlenkeuser, H., 2001. Modulation and amplification of climatic changes in the Northern Hemisphere by the Indian summer monsoon during the past 80 k.y. Geology 29, 63–66.2.0.CO;2>CrossRefGoogle Scholar
Kuhnt, W., Holbourn, A.E., Hall, R., Zuleva, M., Kase, R., 2004. Cenozoic history of the Indonesian throughflow. In: Clift, P., Kuhnt, W., Wang, P., Hayes, D. (Eds.), Continent-Ocean Interactions within East Asian Marginal Seas. Geophysical Monograph Series 149. American Geophysical Union, Washington, D.C., pp. 287–308.Google Scholar
Law, C.S., Owens, N.J.P., 1990. Significant flux of atmospheric nitrous oxide from the northwest Indian Ocean. Nature 346, 826–828.CrossRefGoogle Scholar
Lévy, M., Shankar, D., Andre, J.M., Shenoi, S.S.C., Durand, F., DeBoyer Montegut, C., 2007. Basin-wide seasonal evolution of the Indian Ocean's phytoplankton blooms. Journal of Geophysical Research 112, C12014.CrossRefGoogle Scholar
Madhupratap, M., Prasanna Kumar, M.S., Bhattathiri, P.M.A., Dileep Kumar, M., Raghukumar, S., Nair, K.K.C., Ramaiah, N., 1996. Mechanism of the biological response to winter cooling in the northeastern Arabian Sea. Nature 384, 549–552.CrossRefGoogle Scholar
Meissner, K.J., Galbraith, E.D., Volker, C., 2005. Denitrification under glacial and interglacial conditions: a physical approach. Paleoceanography 20, 3001.CrossRefGoogle Scholar
Mulitza, S., Prange, M., Stuut, J.B., Zabel, M., von Dobeneck, T., Itambi, A.C., Nizou, J., Schulz, M., Wefer, G., 2008. Sahel mega droughts triggered by glacial slowdowns of Atlantic meridional overturning. Paleoceanography 23, 4206.CrossRefGoogle Scholar
Nagoji, S.S., Tiwari, M., 2017. Organic carbon preservation in southeastern Arabian Sea sediments since mid-Holocene: implications to South Asian summer monsoon variability. Geochemistry, Geophysics, Geosystems 18, GC006804.CrossRefGoogle Scholar
Naik, D.K., Saraswat, R., Lea, D.W., Kurtarkar, S.R., Mackensen, A., 2016. Last glacial-interglacial productivity and associated changes in the eastern Arabian Sea. Palaeogeography, Palaeoclimatology, Palaeoecology 483, 147–156.CrossRefGoogle Scholar
Naik, S.S., Godad, S.P., Naidu, P.D., Tiwari, M., Paropkari, A.L., 2014. Early to late Holocene contrast in productivity, OMZ intensity and calcite dissolution in the eastern Arabian Sea. The Holocene 24, 749–755.CrossRefGoogle Scholar
Nair, R.R., Ittekkot, V., Manganini, S.J., Ramaswamy, V., Haake, B., Degens, E.T., Desai, B. N., Honjo, S., 1989. Increased particle-flux to the deep ocean related to monsoons. Nature 338, 749–751.CrossRefGoogle Scholar
Naqvi, S., Naik, H., Pratihary, A., D'Souza, W., Narvekar, P., Jayakumar, D., Devol, A., Yoshinari, T., Saino, T., 2006. Coastal versus open-ocean denitrification in the Arabian Sea. Biogeoscience 3, 621–633.CrossRefGoogle Scholar
Naqvi, S.W.A., 1987. Some aspects of the oxygen-deficient conditions and denitrification in the Arabian Sea. Journal of Marine Research 45, 1049–1072.CrossRefGoogle Scholar
Naqvi, S.W.A., 1994. Denitrification processes in the Arabian Sea. Proceedings of the Indian Academy of Sciences, Earth and Planetary Sciences 103, 279–300.Google Scholar
Naqvi, S.W.A., Jayakumar, D.A., Narvekar, P.V., Naik, H., Sarma, V.S., D'Souza, W., Joseph, T., George, M.D., 2000. Increased marine production of N2O due to intensifying anoxia on the Indian continental shelf. Nature 408, 346–349.CrossRefGoogle ScholarPubMed
Naqvi, S.W.A., Noronha, R.J., 1991. Nitrous oxide in the Arabian Sea. Deep Sea Research 38, 871–889.CrossRefGoogle Scholar
Naqvi, S.W.A., Noronha, R.J., Reddy, C., 1982. Denitrification in the Arabian Sea. Deep-Sea Research Part A. Oceanographic Research Papers 29, 459–469.CrossRefGoogle Scholar
O'Leary, M. H., 1988. Carbon isotopes in photosynthesis. Bioscience 38, 328–336.CrossRefGoogle Scholar
Pahnke, K., Zahn, R., 2005. Southern Hemisphere water mass conversion linked with North Atlantic climate variability. Science 307, 1741–1746.CrossRefGoogle ScholarPubMed
Paulmier, A., Ruiz-Pino, D., 2009. Oxygen minima zones (OMZs) in the modern ocean. Progress in Oceanography 80, 113–128.CrossRefGoogle Scholar
Peterson, L.C., Haug, G.H., Hughen, K.A., Röhl, U., 2000. Rapid changes in the hydrologic cycle of the tropical Atlantic during the last glacial. Science 290, 1947–1951.CrossRefGoogle ScholarPubMed
Pichevin, L., Bard, E., Martinez, P., Billy, I., 2007. Evidence of ventilation changes in the Arabian Sea during the Late Quaternary: implications for denitrification and nitrous oxide emission. Global Biogeochemical Cycles 21, GB4008.CrossRefGoogle Scholar
Rafter, P.A., Bagnell, A., Marconi, D., DeVries, T., 2019. Global trends in marine nitrate N isotopes from observations and a neural network-based climatology. Biogeosciences 16, 2617–2633.CrossRefGoogle Scholar
Reimer, P.J., Baillie, M.G.L., Bard, E., Bayliss, A., Beck, J.W., Blackwell, P.G., Bronk Ramsey, C., et al. , 2009. Intcal09 and Marine09 radiocarbon age calibration curves, 0–50,000 years cal BP. Radiocarbon 51, 1111–1150.CrossRefGoogle Scholar
Rohling, E.J., Zachariasse, W.J., 1996. Red Sea out flow during the last glacial maximum. Quaternary International 31, 77–83.CrossRefGoogle Scholar
Saraswat, R., Lea, D.W., Nigam, R., Mackensen, A., Naik, D.K., 2013. Deglaciation in the tropical Indian Ocean driven by interplay between the regional monsoon and global teleconnections. Earth Planetary Science Letters 375, 166–175.CrossRefGoogle Scholar
Sarkar, A., Ramesh, R., Bhattacharya, S.K., Rajagopalan, G., 1990. Oxygen isotope evidence for a stronger winter monsoon current during the last glaciation. Nature 343, 549–551.CrossRefGoogle Scholar
Sarma, V.V.S.S., 2002. An evaluation of physical and biogeochemical processes regulating perennial suboxic conditions in the water column of the Arabian Sea. Global Biogeochemical Cycles 16, 1082.CrossRefGoogle Scholar
Schäfer, P., Ittekkot, V., 1993. Seasonal variability of δ15N in settling particles in the Arabian Sea and its palaeogeochemical significance. Naturwissenschaften 80, 511–513.CrossRefGoogle Scholar
Schmittner, A., Galbraith, E.D., Hostetler, S.W., Pedersen, T.F., Zhang, R., 2007. Large fluctuations of dissolved oxygen in the India and Pacific Oceans during Dansgaard-Oeschger oscillations caused by variations of North Atlantic deep water subduction. Paleoceanography 22, 3207.CrossRefGoogle Scholar
Schulz, H., von Rad, U., Erlenkeuser, H., 1998. Correlation between Arabian Sea and Greenland climate oscillations of the past 110,000 years. Nature 393, 54–57.CrossRefGoogle Scholar
Shenoi, S.S.C., Shankar, D., Shetye, S.R., 1999. The sea surface temperature high in the Lakshadweep Sea before the onset of the southwest monsoon. Journal of Geophysical Research 104, 703–712.CrossRefGoogle Scholar
Siddall, M., Rohling, E., Almogi-Labin, A., Hemleben, Ch., Meischner, D., Schmelzer, I., Smeed, D.A., 2003. Sea-level fluctuations during the last glacial cycle. Nature 423, 853–858.CrossRefGoogle ScholarPubMed
Sigman, D.M., Altabet, M. A., Michener, R.H., McCorkle, D.C., Fry, B., Holmes, R.M. 1997. Natural abundance-level measurement of the nitrogen isotopic composition of oceanic nitrate: an adaptation of the ammonia diffusion method. Marine Chemistry 57, 227–242.CrossRefGoogle Scholar
Sigman, D.M., Karsh, K.L., Casciotti, K. L. 2009. Nitrogen isotopes in the ocean. In: Steele, J.H., Turekian, K.K., Thorpe, S.A. (Eds.), Encyclopedia of Ocean Sciences. Academic Press, London, 40–54.CrossRefGoogle Scholar
Singh, A.D., Jung, S.J.A., Darling, K., Ganeshram, R., Ivanochko, T., Kroon, D., 2011. Productivity collapses in the Arabian Sea during glacial cold phases. Paleoceanography 26, PA3210.CrossRefGoogle Scholar
Singh, A.D., Kroon, D., Ganeshram, R., 2006. Millennial scale variations in productivity and OMZ intensity in the eastern Arabian Sea. Journal of Geological Society of India 68, 369–377.Google Scholar
Sowers, T., Alley, R.B., Jubenville, J., 2003. Ice core records of atmospheric N2O covering the last 106,000 years. Science 301, 945–948.CrossRefGoogle ScholarPubMed
Stuiver, M., Reimer, P.J., 1993. Extended 14C database and revised CALIB radiocarbon calibration program. Radiocarbon 35, 215–230.CrossRefGoogle Scholar
Tiwari, M., Ramesh, R., Bhushan, R., Sheshshayee, M.S., Somayajulu, B.L.K., Jull, A.J.T., Burr, G.S., 2010. Did the Indo-Asian summer monsoon decrease during the Holocene following insolation? Journal of Quaternary Science, 25, 1179–1188.CrossRefGoogle Scholar
Tiwari, M., Ramesh, R., Somayajulu, B.L.K., Jull, A.J.T., Burr, G.S., 2006. Paleomonsoon precipitation deduced from a sediment core from the equatorial Indian Ocean. Geo-Marine Letters 26, 23–30.CrossRefGoogle Scholar
Torrence, C., Compo, G.P., 1998. A practical guide to wavelet analysis. Bulletin of American Meteorological Society 79, 61–78.2.0.CO;2>CrossRefGoogle Scholar
Tripathi, S., Behera, P., Tiwari, M., 2020. Evolution and dynamics of the denitrification in the Arabian Sea on millennial to million-year timescale. Current Science 119, 282–290.Google Scholar
Tripathi, S., Tiwari, M., Lee, J., Khim, B.K., IODP Expedition 355 Scientists, 2017. First evidence of denitrification vis-à-vis monsoon in the Arabian Sea since Late Miocene. Scientific Reports 7, 43056.CrossRefGoogle ScholarPubMed
United States Environmental Protection Agency, 2010. Methane and Nitrous Oxide Emissions from Natural Sources. EPA 430-R-10-001, Office of Atmospheric Programs, Washington, D.C.,Google Scholar
Wang, H., Liu, H., Cui, H., Abrahamsen, N., 2001. Terminal Pleistocene/Holocene palaeoenvironmental changes revealed by mineral-magnetism measurements of lake sediments for Dali Nor area, southeastern inner Mongolia plateau, China. Palaeogeography, Palaeoclimatology, Palaeoecology 170, 115–132.CrossRefGoogle Scholar
Wang, Y., Cheng, H., Edwards, R.L., Kong, X., Shao, X., Chen, S., Wu, J., Jiang, J., Wang, X., An, Z., 2008. Millennial- and orbital-scale changes in the East Asia monsoon over the past 224,000 years. Nature 451, 1090–1093.CrossRefGoogle Scholar
Waser, N.A.D., Harrison, P.J., Nielsen, B., Calvert, S.E., Turpin, D.H., 1998. Nitrogen isotope fractionation during the uptake and assimilation of nitrate, nitrite, ammonium, and urea by a marine diatom. Limnology and Oceanography 43, 215–224.CrossRefGoogle Scholar
Weldeab, S., Lea, D.W., Schneider, R.R., Andersen, N., 2007. 155,000 years of West African monsoon and ocean thermal evolution: Science 316, 1303–1307.CrossRefGoogle ScholarPubMed
Supplementary material: File

Nagoji and Tiwari supplementary material

Nagoji and Tiwari supplementary material

Download Nagoji and Tiwari supplementary material(File)
File 2 MB