釷-234/鈾-238不平衡法(水體估算釷-234通量乘以下沈顆粒之有機碳(POC)與釷-234(POC/234Th)比值)是估算顆粒性有機碳通量的方法之一，但近年研究發現選擇大顆粒的POC/234Th比值對碳通量估算有很大的變動，另外也有學者直接利用上層海域懸浮顆粒的粒徑分佈來估算碳通量。這些方法皆須了解下沉顆粒的粒徑分佈，雖然Hung and Gong (2010)與Hung et al. (2012)已研究下沉顆粒的粒徑分佈，但得到之樣品數量只限於少數區域，因此目前下沉顆粒的粒徑分佈尚未有完整的研究。本研究於2011-2012在矽藻為主要浮游植物的北南海、台灣東北湧升區和超微浮游植物為主的西北太平洋海域，利用三種不同儀器(現場雷射粒徑分析儀、直立式與旋轉式沉積物收集器)採集的沉降顆粒，測量不同粒徑(1-50μm、50-330 μm 與>330 μm，本文定義<50 μm 為小顆粒)之POC flux 與釷-234 活度。實驗結果發現不論是現場雷射粒徑分析儀或沉積物收集器(直立式與旋轉式)的POC flux 在三種不同海洋環境下皆以小顆粒居多，直立式與旋轉試測得之小顆粒POC 分別佔46~66 %與37~75 %，而掃描式電顯圖片也證實了小顆粒的存在。除此之外，以模式計算的小顆粒POC flux 和沉積物收集器實測值相當接近，然而兩者估算之大顆粒POC flux 卻有明顯的差距，原因尚待探討。本研究結果顯示，過去研究認為大顆粒為主要下沈顆粒之觀念，可能完全忽略小顆粒的貢獻，因此建議使用234Th/238U 不平衡時應該選用沈降顆粒進行POC flux 之估算。

234Th/238U has been used to estimate particulate organic carbon (POC) export fluxes, based on the POC/234Th ratio of sinking particles and the 234Th flux, in the ocean. However, the 234Th-derived POC flux may be significantly biased due to the variation of use POC/234Th ratios from large particles (>50μm). More recently, some studies use particle size distributions in the upper ocean to calculate POC flux. Although Hung and Gong (2010) and Hung et al. (2012) have measured the size distributions in sinking particle, but their experiments were limited in some regions. Therefore, the size distributions in sinking particle are not clearly. In this study, we collected sinking particles with three different instruments (Laser in-situ Scattering and Transmissometry (LISST-100X), cylindrical and conical sediment traps) from the northern South China Sea, the upwelling region off the northeast Taiwan (where diatoms are the most dominant group) and the Northwestern Pacific (where picoplanktondominated), measured POC and 234Th data for various particle size classes (1-50 μm, 50-330 μm and >330 μm, (herein we defined that < 50μm is the “ small particle”). The results show the small particles, investigated by-cylindrical and conical traps, contained the largest proportion of POC (46~66%, by cylindrical traps) and (37~75%, by conical traps) and the distribution of particle size measured by LISST-100X howed small particles had the elevated shares of total particle volume. SEM images of bulk (without sequential filtration) sinking particles also evidence that sinking particles contained many small particles. Besides, the model-derived POC flux in small particles using particle size distribution is quite comparable with the measured POC flux by sediment trap, while the POC fluxes measured by both methods show pronounced difference suggesting that it is worthy for studying in the future. Overall, our results suggest that the contribution of particles smaller than 50 μm to the sinking POC flux can be a major fraction of the total sinking flux, and thus, particles smaller than 50 μm cannot be ignored when using Th-234/U-238 disequilibrium to estimate POC flux in the water column.

致謝 i
摘要 ii
Abstract iv
目錄 vi
圖目錄 ix
表目錄 xi
第一章 前言 1
1.1 海洋碳循環的機制及重要性 1
1.2 沉積物收集器 2
1.3 釷-234：顆粒性有機碳示蹤劑 4
1.4 顆粒粒徑分佈 6
1.5 研究現況 6
1.6 研究動機與目的 9
第二章 材料與方法
2.1 研究區域 13
2.2 採樣項目與採集方式 13
2.2.1 採水 13
2.2.2沉積物收集器 15
2.2.3現場雷射粒徑分析儀(LISST-100X) 15
2.3樣品處理與分析樣 16
2.3.1 採水瓶之水樣 16
2.3.2沉降顆粒樣品16
2.3.2.1整管水樣、採後過濾法及自然分樣法 19
2.3.2.2顆粒計數器(Beckman-Coulter Multisizer III) 19
第三章 結果與討論
3.1三個不同海洋環境水文特徵 26
3.1.1不同海洋環境之水文、營養鹽、葉綠素及顆粒性有機碳結果 26
3.1.2穿透率(TM) 27
3.2 連續過濾(SS)與自然分樣法(NS)之結果 28
3.3 收集時間對沉降顆粒大小分佈及碳通量結果 30
3.4 沉降顆粒(bulk)之顆粒性有機碳通量與釷-234通量之變化 32
3.4.1 北南海海域 33
3.4.2台灣東北湧升區與西北太平洋 34
3.5不同海域沉降顆粒之顆粒大小分佈 35
3.5.1 現場雷射粒徑分析儀(LISST-100X)結果 35
3.5.2 掃描式電子顯微鏡(SEM)結果 36
3.5.3 沉積物收集器(直立式與旋轉式)有機碳與釷-234通量 37
3.6 顆粒分佈對顆粒性有機碳輸出的重要性 40
3.6.1釷-234：顆粒性有機碳示蹤劑 40
3.6.2估算顆粒性有機碳通量-顆粒分佈 42
第四章 結論 58
參考文獻 60
附錄 75

中文部分
李嵩嵐，2009，台灣東北湧升區的顆粒性有機碳輸出通量，國立台灣海洋大學海洋環境化學與生態研究所碩士論文，共55頁。
謝鈞盛，2010，不同海洋環境下不同粒徑沉降顆粒POC/234Th 比值之探討，國立台灣海洋大學海洋環境化學與生態研究所碩士論文，共57頁。
胡博凱，2011，POC/234Th ratio 在沉降顆粒與懸浮顆粒之比較，國立台灣海洋大學海洋環境化學與生態研究所碩士論文，共48頁。
英文部分
Alonso-Gonzalez, I. J., Aristegui, J., Lee, C., Calafat, A., 2010 Regional and temporal variability of sinking organic matter in the subtropical northeast Atlantic Ocean: a biomarker diagnosis. Biogeoscience 7, 2101–2115.
Abramson, L., Lee, C., Liu, Z., Wakeham, S.G., Szlosek, J., 2010. Exchange between suspended and sinking particles in the northwest Mediterranean as inferred from the organic composition of in situ pump and sediment trap samples. Limnology and Oceanography 55, 725–737.
Agrawal, Y. C., Pottsmith, H. C., 2000. Instruments for particle size and settling velocity observations in sediment transport. Marine Geology 168, 89-114.
Alldredge, A.L., Gotschalk, C.C., 1989. In situ settling behavior of marine snow. Limnology and Oceanography 33, 339–351.
Armstrong, R. A., Lee, C., Hedges, J. I., Honjo, S., Wakeham, S.W., 2002. A new, mechanistic model for organic carbon fluxes in the ocean based on the quantitative association of POC with ballast minerals. Deep-Sea Research II 49, 219–236.
Asper, V.L., 1987. Measuring the flux and sinking speed of marine snow aggregates. Deep-Sea Research 34, 1–17.
Bacon, M.P., Anderson, R.F., 1982. Distribution of thorium isotopes between dissolved and particulate forms in the deep sea. Journal of Geophysical Research 87, 2045–2056.
Barnola, J.M., Raynaud, D.C. Lorius, N., Barkov, I. 2003. Historical CO2 record from the Vostok ice core. In Trends: ACompendium of Data on Global Change, Carbon DioxideInformation Analysis Center, Oak Ridge National Laboratory, U.S.Department of Energy, Oak Ridge, Tennessee, U.S.A.
Benitez-Nelson, C., Buesseler, K.O.,Kral, D., Andrews, J., 2001. A time-series study of particular matter export in the North Pacific subtropical gyre based upon 234Th/238U disequilibrium. Deep-Sea Research I 48, 2595-2611.
Bhat, S.G., Krishnaswamy, S., Lal, D., Rama, D., Moore, W.S., 1969. Th-234/ U-238 ratios in the ocean. Earth and Planetary Science Letters 5, 483–491.
Billet, D.S.M., Lampitt, R.S., Rice, A.L., Mantoura, R.C.F., 1983. Seasonal sedimentation of phytoplankton to the deep-sea benthos. Nature 302, 520-522.
Boyd, P., Newton, P., 1995. Evidence of potential influence of planktonic community structure on the interannual variability of particulate organic carbon flux. Deep-Sea Research I 42, 619-639.
Brew, H. S., Moran, S. B., Lomas, M. W., Burd, A. B., 2009. Plankton community composition, organic carbon and thorium-234 particle size distributions, and particle export in the Sargasso Sea. Journal of Marine Research 67, 845–868.
Buesseler, K.O., 1998. The decoupling of production and particulate export in the surface ocean. Global Biogeochemical Cycles 12, 297-310.
Buesseler, K.O., Andrews, J.A., Hartman, M.C., Belastock, R., Chai, F., 1995. Regional estimates of the export flux of particulate organic-carbon derived from Th-234 during the JGOFS EqPac program. Deep-Sea Research II 42, 777-804.
Buesseler, K.O., Antia, A.N., Chen, M., Fowler, S.W., Gardner, W.D., Gustafsson, &#214;., Harada, K., Michaels, A.F., VanDerLoeff'o, M.R., Sarin, M., Steinberg, D.K., Trull, T., 2007. An assessment of the use of sediment traps for estimating upper ocean particle fluxes. Journal of Marine Research 65, 345-416.
Buesseler, K.O., Bacon, M.P., Cochran, J.K., Livingston, H.D., 1992. Carbon and nitrogen export during the JGOFS North-Atlantic Bloom Experiment estimated from Th-234/U-238 disequilibria. Deep-Sea Research I 39, 1115–1137.
Buesseler, K.O., Ball, L., Andrews, J., Cochran, J.K., Hirschberg, D.J., Bacon, M.P. Fleer, A., Brzezinski, M., 2001. Upper ocean export of particulate organic carbon and biogenic silica in the Southern Ocean along 170°W. Deep-Sea Research II 48, 4275-4297.
Buesseler, K.O., Benitez-Nelson, C.R., Moran, S.B., Burd, A., Charette, M., Cochran, J.K., Coppola, L., Fisher, N.S., Fowler, S.W., Gardner, W.D., Guo, L.D., Gustafsson, &#214;., Lamborg, C., Masque, P., Miquel, J.C., Passow, U., Santschi, P.H., Savoye, N., Stewart, G., Trull, T., 2006. An assessment of particulate organic carbon to thorium-234 ratios in the ocean and their impact on the application of Th-234 as a POC flux proxy. Marine Chemistry 100, 213-233.
Buesseler, K.O., Steinberg, D.K., Michaels, A.F., Johnson, R.J., Andrews, J.E., Valdes, J.F., 2000. A comparison of the quantity and composition of material caught in a neutrally buoyant versus surface-tethered sediment trap. Deep-Sea Research I 47, 277-294.
Burd, A.B., Jackson, G.A., 2009. Particle aggregation. Annals Review Marine Science 1, 65–90.
Charette, M.A., Moran, S.B., Bishop, J.K.B., 1999. Seasonal changes in particulate organic carbon export in the North East Pacific indicated from 234Th/238U disequilibrium. Deep-Sea Research II 46, 885-906.
Chisholm, S.W., 2000. Oceanography: Stirring times in the Southern Ocean. Nature 407, 685-687.
Coale, K.H., Bruland, K.W., 1985. Th-234/U-238 disequilibria within the California current. Limnology and Oceanography 30, 22-33.
Coale, K.H., Bruland, K.W., 1987. Oceanic stratified euphotic zone as elucidated by Th-234:U-238 disequilibria. Limnology and Oceanography 32, 189-200.
Cochran, J. K., Barnes, C., Achman, D., Hirschberg, D. T., 1995. Thorium - 234/Uranium-238 disequilibrium as an indicator of scavenging rates and particulate organic carbon fluxes in the Northeast Water Polynya, Greenland. Journal of Geophysics Research 100, 4399–4410.
Cochran, J.K., Buesseler, K.O., Bacon, M.P., Wang, H.W., Hirschberg, D.J., Ball, L., Andrews, J.A., Crossin, G., Fleer, A.P., 2000. Short-lived thorium isotopes (Th-234, Th-228) as indicators of POC export and particle cycling in the Ross Sea, Southern Ocean. Deep-Sea Research II 47, 3451-3490.
Conte, M.H., Ralph, N., Ross, E.H., 2001. Seasonal and interannual variability in deep ocean particle fluxes at the Oceanic Flux Program (OFP)/Bermuda Atlantic Time Series (BATS) site in the western Sargasso Sea near Bermuda. Deep Sea Research II 48, 1471-1501.
Coppola, L., Roy-Barman, M., Wassmann, P., Mulsow, S., Jeandel, C., 2002. Calibration of sediment traps and particulate organic carbon export using 234Th in the Barents Sea. Marine Chemistry 80, 11-26.
Droppo, I. G., Krishnappan, B. G., Rao, S. S., Ongley, E. D., 1995. Investigation of a sequential filtration technique for particle fractionation. Environment Science Technologic 29, 546–550.
Dunne, J., Murry, J., 1999. Sensitivity of 234Th export to physical processes in the central equatorial Pacific. Deep-Sea Research I 46, 831-854.
Eppley, R.W., 1989. New production: history, methods, problems. In: Berger, W. H., Smetacek, V. S., Wefer, G. (Eds.) Productivity of the Ocean: Present and Past. Wiley, New York. 85-97.
Falkowski, P., Scholes, R.J., Boyle, E., Canadell, J., Canfield, D., Elser, J., Gruber, N., Hibbard, K., Hoegberg, P., Linder, S., Mackenzie, F.T., Moore, B., Pedersen, T., Rosenthal, Y., Seitzinger, S., Smetacek, V., Steffen, W., 2000. The global carbon cycle: A test of our knowledge of earth as a system. Science 290, 291-296.
Feely, R.A., Sarbine, C.L., Takahashi, T., Wanninkhof, R., 2001. Uptake and storage of carbon dioxide in the ocean: the global CO2 survey. Oceanography 14,18-32.
Fowler, S.C., Knauer, G.A., 1986. Role of large particles in the transport of elements and organic compounds through the oceanic water column. Progress in Oceanography 16, 147-194.
Gardner, W. D., Hinga, K. R., Marra, J. 1983. Observations on the degradation of biogenic material in the deep ocean with implications on the accuracy of sediment trap fluxes. Journal of Marine Research 41, 195–214.
Gardner, W.D., 1985. Effect of tilt on sediment trap efficiency. Deep-Sea Research 32, 349-361.
Gardner, W. D., 2000. Sediment trap sampling in surface waters. In The Changing Ocean Carbon Cycle: A Midterm Synthesis of the Joint Global Ocean Flux Study (eds. R. B. Hanson, H. W. Ducklow and J. G. Field). Cambridge University Press, pp. 240–281.
Gehlen, M., Bopp, L., Emprin, N., Aumont, O., Heinze, C., Ragueneau, O., 2006. Reconciling surface ocean productivity, export fluxes and sediment composition in a global biogeochemical ocean model. Biogeosciences 3, 521–537.
Guidi, L., Jackson, G.A., Stemmann, L., Miquel, J.C., Picheral, M., Gorsky, G., 2008. Particle size distribution and flux in the mesopelagic: a close relationship. Deep Sea Research I, 55, 1364–1374.
Guidi, L., Stemmann, L., Legendre, L., Picheral, M., Prieur, L., Gorsky, G., 2007. Vertical distribution of aggregates (>110mm) and mesoscale activity in the northeastern atlantic: effects on the deep vertical export of surface carbon. Limnology and Oceanography 52, 7–18.
Guo, L., Hung, C.C., Santschi, P.H., Walsh, I.D., 2002. 234Th scavenging and its relationship to acid polysaccharide abundance in the Gulf of Mexico. Marine Chemistry 78, 103-119.
Guo, L., Santschi, P.H., Baskaran, M., 1997. Interaction of thorium isotopes with colloidal organic matter in oceanic environments. Colloids and Surfaces I 120, 255-272.
Gust, G., Byrne, R. H., Bernstein, R. E., Betzer, P. R., Bowles, W. 1992. Particle fluxes and moving fluids：experience from synchronous trap collections in the Sargasso Sea. Deep-Sea Research, 39, 1071-1083.
Hodge, V.F., Koide, M., Goldberg, E.D., 1979. Particulate uranium, plutonium and polonium in the biogeochemistries of the coastal zone. Nature 277, 206-209.
Honjo, S., Dymond, J., Collier, R., Manganii, S.J., 1995. Export production of particles to the interior of equatorial Pacific Ocean during 1992 EqPac experiment, Deep-Sea Research I 42, 831-870.
Honjo, S., Dymond, J., Prell, W., Ittekkot, V., 1999. Mooson-controlled export fluxes to the interior of the Arabian Sea, Deep-Sea Research II 46, 1859-1902.
Hsu, T.R., Liu, J.T., 2010. In-situ estimations of the density and porosity of flocs of varying sizes in a submarine canyon. Marine Geology 276, 105-109.
Hung, C.C., Chen, X., Santschi, P.H., Zhang, S.J., Schwehr, K.A., Quigg A., Guo, L., Gong, G.C., Pinckney, J.L., Long, R.A., Wei, C.L., 2010a. Evaluation of the POC and 234Th fluxes in the Gulf of Mexico from sediment traps and size-fractionated POC/234Th ratios in suspended particles. Marine Chemistry 121, 132-144.
Hung, C. C., Guo, L., Roberts, K., Santschi, P.H., 2004. Upper ocean carbon flux determined by 234Th and sediment traps in the Gulf of Mexico. Geochemical Journal 38, 601-611.
Hung, C.C., Gong, G.C., 2007. Export flux of POC in the main stream of the Kuroshio. Geophysical Research Letters 34, L18606.
Hung, C.C., Gong, G.C., 2010. POC/234Th ratios in particles collected in sediment traps in the northern South China Sea. Estuarine, Coastal and Shelf Science 88, 303–310.
Hung, C.C., Gong, G. C., Chung, W.C., Kuo, W.T. Lin, F.C., 2009. Enhancement of particulate organic carbon flux induced by the atmospheric forcing in the subtropical oligotrophic northwest Pacific Ocean. Marine Chemistry 113, 19–24.
Hung, C.C., Gong, G.C., Santschi, P.H., 2012. 234Th in different size classes of sediment trap collected particles from the Northwestern Pacific Ocean. Geochimica et Cosmochimica Acta 91, 60-74.
Hung, C.C., Wei, C.L., 1992. Th-234 scavenging in the water column off southwestern Taiwan. Terrestrial, Atmospheric and Oceanic Sciences 3, 183-197.
Hung, J.J., Lin, C.S., Chung, Y.C., Hung, G.W., Liu, W.S., 2003. Lateral flux of biogenic particles through the Mien-Hua Canyon in the southern East China Sea slope. Continental Shelf Research 23, 935-955.
Iversen, M.H., Nowald, N., Ploug, H., Jackson, G.A., Fischer, G., 2010. High resolution profiles of vertical particulate organic matter export off Cape Blanc., Maur- itania: degradation processes and ballasting effects. Deep-Sea Research I 57, 771–784.
Jackson, G.A., 1995. Comparing observed changes in particle size spectra with those predicted using coagulation theory. Deep-Sea Research II 42, 159–184.
Jackson, G.A., Checkley, D.M., 2011. Particle size distributions in the upper 100 m water column and their implications for animal feeding in the plankton. Deep-Sea Research I 58, 283-297.
Jackson, G.A., Waite, A.M., Boyd, P.W., 2005. Role of algal aggregation in vertical carbon export during SOIREE and in other low biomass environments. Geophysics Research Letter 32, L13607. doi : 10. 1029/2005GL023180.
Kawakami, H., Honda, M.C., 2007. Time-series observation of POC fluxes estimated from 234Th in the northwestern North Pacific. Deep-Sea Research I 54, 1070-1090.
Ku, T.L., Knauss, K.G., Mathiew, G.G., 1977. Uranium in open ocean: concentration and isotopic composition. Deep-Sea Research I 24, 1005-1017.
Karl, D.M., Tilbrook, B.D., Tien, G., 1991. Seasonal coupling of organic matter production and particle flux in the western Bransfield Strait, Antarctica, Deep-Sea Research I 38, 1097-1126.
Lampitt, R.S., Boorman, B., Brown, L., Lucas, M., Salter, I., Sanders, R., Saw, K., Seeyave, S., Thomalla, S. J., Turnewitsch, R. 2008. Particle export from the euphotic zone: estimates using a novel drifting sediment trap, 234Th and new production. Deep-Sea Research I 55, 1484–1502.
Lampitt, R.S., Hillier, W.R., Challenor, P.G., 1993. Seasonal and diel variation in the open ocean concentration of marine snow aggregates. Nature 362, 737-739.
Lee, C., Wakeham, S.G. Hedges, J. I. 1988. The measurement of oceanic particle flux-are “swimmer” a problem?, Oceanography 1, 34-36.
Lepore, K., Moran, S.B., Burd, G.A., Jackson, J.N., Smith, J.N., Kelly, R.P., Kaberi, H., Tavrakakis, S., Assimakopoulou, G., 2009. Sediment trap and in-situ pump sizefractionated POC/234Th ratios in the Mediterranean Sea and Northwest Atlantic : implications for POC export. Deep-sea Research I 56, 599-613.
Logan, B.E., Passow, U., Alldredge, A.L. 1994 Variable retention of diatoms on screens during size separations. Limnology and Oceanography 39, 390–395.
Lohrenz, S.E., Knauer, G.A., Asper, V.L., Tuel, M., Michaels, A.F., Knap, A.H., 1992. Seasonal and interannual variablilty in primary production and particle flux in the northwestern Sargasso Sea: US JGOFS /Bermuda Atlantic Time Series. Deep-Sea Research I 39, 1373-1391.
Maiti, K., Benitez-Nelson, C.R., Rii, Y., Bidigare, R.R., 2008. The influence of a mature cyclonic eddy on particle export in the lee of Hawaii. Deep-Sea Research II 55, 1445–1460.
McCave, I.N., 1975. Vertical flux of particles in the ocean. Deep-Sea Research 22, 491-502.
McCave, I.N., 1984. Size spectra and aggregation of suspended particles in the deep ocean. Deep-Sea Research 31, 329-352.
Michaels, A.F., Silver, M.W., 1988. Primary production, sinking fluxes and the microbial food web, Deep-Sea Research 35, 473-490.
Moran, S.B., Weinstein, S.E. Edmonds, H.N., Edmonds, H.N., Smith, J.N., Kelly, R.P., Pilson, M.E.Q., Harrison, W.G., 2003. Does 234Th/238U disequilibrium provide an accurate record of the export flux of particulate organic carbon from the upper ocean? Limnology and Oceanography 48(3), 1018-1029.
Morris, P.J., Sanders, R., Turnewitsch, R., Thomalla S., 2007. 234Th – derived particulate organic carbon export from an island- induced phytoplankton bloom in the Southern Ocean. Deep-Sea Research II 54, 2208–2232.
Mullin, M.M., Sloan, P.R., Eppley, R.W., 1966. Relationship between carbon content, cell volume, and area in phytoplankton. Limnology and Oceanography 11, 307–311.
Murray, J.W., Downs, J.N., Strom, S., Wei, C.L., Jannasch, H.W., 1989. Nutrient assimilation, export production and Th-234 scavenging in the eastern equatorial pacific. Deep-Sea Research I 36, 1471-1489.
Murray, J.W., Young, J., Newton, J., Dunne, J., Chapin, T., Paul, B., McCarthy, J.J., 1996. Export flux of particulate organic carbon from the central equatorial Pacific determined using a combined drifting trap Th-234 approach. Deep-Sea Research II 43, 1095-1132.
Neuer, S., Davenport, R., Freudenthal, T., Wefer, G., Llinas, O., Rueda, M.J., Steinberg, D.K., Karl D.M., 2002. Differences in the biological carbon pump at three subtropical ocean sites. Geophysics Research Letter. 29, 1885.
Noji, T.T., Borsheim, K.Y., Rey, F., Nortvedt, R., 1999. Dissolved organic carbon associated with sinking particles can be crucial for estimates of vertical carbon flux. Sarsia 84, 129-135.
Petit, J. R., Raynaud, D., Lorius, C., Jouzel, J., Delaygue, G., Barkov, N. I., Kotlyakov, V.M. 2000. Historical isotopic temperature record from the Vostok ice core, In Trends: A Compendium of Data on Global Change, Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A. doi: 10.3334/CDIAC/cli.006.
Pilskaln, C.H., Lehmann, C., Paduan, J.B., Silver, M.W., 1998. Spatial and temporal dynamics in marine aggregate abundance, sinking rate and flux: Monterey Bay, central California. Deep-Sea Research II 45, 1803–1837.
Richardson, T.L., Jackson, G.A., 2007. Small phytoplankton and carbon export from the surface ocean. Science 315, 838–840.
Santschi, P.H., Hung, C.C., Guo, L., Schultz, G.G., Pinckney, J., Walsh, I., 2003. Control of acid polysaccharide production, 234Th and particulate organic carbon export flux by marine organisms. Geophysics Research Letters 30.
Santschi, P.H., Murray, J.W., Baskaran, M., Benitez-Nelson, C.R., Guo, L.D., Hung, C.C., Lamborg, C., Moran, S.B., Passow, U., Roy-Barman, M., 2006. Thorium speciation in seawater. Marine Chemistry 100, 250-268.
Savoye, N., Benitez-Nelson, C., Burd, A.B., Cochran, J.K., Charrette, M., Buesseler, K.O., Jackson, G., Roy-Barman, M., Schmidt, S., Elskens, M., 2006. 234Th sorption and export models in the water column: A review. Marine Chemistry 100, 234-249.
Savoye, N., Trull, T.W. Jacquet, S.H.M., Navez, J., Dehars, F., 2008. 234Th-based export fluxes during a natural iron fertilization experiment in the Southern Ocean (KEOPS). Deep-Sea Research II 55, 841-855.
Sheldon, R.W. Sutcliffe, W.H.J., 1969. Retention of marine particles by screens and filters. Limnology and Oceanography 14, 441–444.
Siegenthaler, U., Samiento, J. L., 1993. Atmospheric carbon dioxide
and the ocean, Nature 365, 119-125.
Szlosek, J., Cochran, J.K., Miquel, J.C., Masque, P., Armstrong, R.A., Fowler, S.W., Gasser, B., Hirschberg, D. J., 2009. Particulate organic carbon–234Th relationship in particles separated settling velocity in the northwest Mediterranean Sea. Deep-Sea Res earch II 56, 1519–1532.
Takahashi, T., 2004. The fate of industrial carbon dioxide. Science 305, 352-353.
Tsunogai, S., Minagawa, M., 1976. Vertical flux of organic materials estimated from Th-234 in the ocean. Joint Oceanographic Assembly, Edinburgh 156, 13-24.
Turnewitsch, R., Springer, B.M., Kiriakoulakis, K., Vilas, J.C., Aristegui, J., Wolff, G., Peine, F., Werk, S., Graf, G., Waniek, J.J., 2007. Determination of particulate organic carbon (POC) in seawater: The relative methodological importance of artificial gains and losses in two glass-fiber-filter-based techniques. Marine Chemistry 105, 208-228.
Volk, T., Hoffert, M.I., 1985. Ocean carbon pumps: analysis of relative strengths and efficiencies in ocean-drive atmospheric CO2 changes. In: Sundquist, E.T., Broecker, W.S. (Eds.), The Carbon Cycle and Atmospheric CO2: Natural Variations Archean to Present. Geophysical Monograph, vol. 32. American Geophysical Union, pp. 99-110.
Waite, A., Nodder, S.D., 2001. The effect of in situ iron addition on the sinking rates and export flux of Southern Ocean diatoms. Deep-Sea Research I 48, 2635–2654.
Waite, A.M., Safi, K., Hall, J., Nodder, S., 2000. Mass sedimentation of picoplankton embedded in organic aggregates. Limnology and Oceanography 45, 87–97.
Walsh, I., Fisher, K., Murray, D., Dymond, J., 1988. Evidence for resuspension of rebound particles from near-bottom sediment traps.
Deep-Sea Research 35, 59-70.
Wei, C.L., Chou, L.H., Tsai, J.R., Wen, L.S., Pai, S.C., 2009. Comparative geochemistry of 234Th, 210Pb, and 210Po: a case study in the Hung-Tsai Trough off southwestern Taiwan. Terrestrial, Atmospheric and Oceanic Sciences 20, 411-423.
Wei, C.L., Murray, J.W., 1992. Temporal variations of Th-234 activity in the water column of Dabob Bay: Particle scavenging. Limnology and Oceanography 37, 296-314.
White, J. R. 1990. The use of sediment traps in high-energy enviroments. Marine Geophysics Research, 12, 145-152.
Wormuth, J.H., Ressler, P.H., Cady, R.B., Harris, E.J., 2000. Zooplankton and micronekton in cyclones and anticyclones in the Northeast Gulf of Mexico. Gulf of Mexico Science, 23–34.