夏季黄海颗粒有机碳的输出通量——基于234Th:238U 不平衡方法的研究
A Study of Particulate Organic Carbon Export in the Yellow Sea in Summer Based on 234Th:238U Disequilibrium

作者: 赵道辰 :厦门大学环境与生态学院,厦门;

关键词: 黄海颗粒有机碳输出通量234Th真光层Yellow Sea POC Export Fluxes 234Th Euphotic Zone

摘要:
为了研究黄海生物泵过程,2009 年夏季利用234Th 示踪法对黄海进行了颗粒有机碳输出通量的研究。以小体积海水 MnO2共沉淀-β 计数法测定海水中总态及颗粒态234Th 的活度,在上层水柱中颗粒态及总态234Th活度显著低于母体238U 的活度。基于上层水体中234Th:238U 的不平衡并结合一维稳态不可逆清除模型,估算出从真光层底部输出的 POC 通量。夏季黄海颗粒有机碳的输出通量变化范围为 12.7 ± 1.7~92.0 ± 21.0 mmol C m−2·d−1,平均值为 45.3 ± 41.5 mmol C m−2·d−1 (n = 3, ±1SD)。 本研究结果为进一步厘清黄海在全球碳循环的作用提供了参考。

Abstract:
234Th was utilized as a tracer of particulate organic carbon (POC) fluxes from the euphotic zone to study biological pump process in the Yellow Sea in the summer of 2009. 234Th in the upper water column was determined by using a modified small-volume MnO2 co-precipitation technique, and its deficit with respect to 238U was found to be evident throughout the upper water column. The 234Th:238U disequilibrium in the upper waters and one-dimensional irreversible steady state model were used to calculate the POC export fluxes from the bottom of euphotic layer. The POC export flux varied from 12.7 ± 1.7 mmol C m−2·d−1 to 92.0 ± 21.0 mmol C m−2·d−1, with an average of 45.3 ± 41.5 mmol C m−2·d−1 (n = 3, ±1SD). The results will provide a better understanding of the role that the Yellow Sea plays in the global carbon cycle.

文章引用: 赵道辰 (2013) 夏季黄海颗粒有机碳的输出通量——基于234Th:238U 不平衡方法的研究 。 气候变化研究快报, 2, 159-164. doi: 10.12677/CCRL.2013.24027

参考文献

[1] M. M. Rutgers van der Loeff, K. Buesseler, U. Bathmann, I. Hense and J. Andrews. Comparison of carbon and opal export rates between summer and spring bloom periods in the region of the Antarctic Polar Front, SE Atlantic. Deep Sea Research Part II, 2002, 49: 3849-3869.

[2] D. Amiel, J. K. Cochran. Terrestrial and marine POC fluxes derived from 234Th distributions and δ13C measurements on the Mackenzie shelf. Journal of Geophysical Research, 2008, 113, C03S06.

[3] D. Amiel, J. K. Cochran and D. J. Hirschberg. 234Th/238U dis- equilibrium as an indicator of the seasonal export flux of par- ticulate organic carbon in the North Water. Deep Sea Research Part II, 2002, 49: 5191-5209.

[4] C. R. Benitez-Nelson, K. O. Buesseler and G. Crossin. Upper ocean carbon export, horizontal transport, and vertical eddy dif- fusivity in the southwestern Gulf of Maine. Continental Shelf Research, 2000, 20: 707-736.

[5] M. A. Charette, S. B. Moran, S. M. Pike and J. N. Smith. Inves- tigating the carbon cycle in the Gulf of Maine using the natural tracer thorium-234. Journal of Geophysical Research, 2001, 106(C6): 11553-11179.

[6] J. K. Cochran, K. O. Buesseler, M. P. Bacon, et al. Short-lived thorium isotopes (234Th, 228Th) as indicators of POC export and particle cycling in the Ross Sea, Southern Ocean. Deep Sea Re- search Part II, 2000, 47: 3451-3490.

[7] J. K. Cochran, C. Barnes, D. Achman and D. Hirschberg. Tho- rium-234/Uranium-238 disequilibrium as an indicator of scav- enging rates and particulate organic carbon fluxes in the North- east Water Polynya, Greenland. Journal of Geophysical Re- search-Oceans, 1995, 100(C3): 4399-4410.

[8] C. Lalande, K. Lepore, L. W. Cooper, J. M. Grebmeier and S. B. Moran. Export fluxes of particulate organic carbon in the Chuk- chi Sea: A comparative study using 234Th/238U disequilibria and drifting sediment traps. Marine Chemistry, 2007, 103: 185-196.

[9] K. Lepore, S. B. Moran, J. M. Grebmeier, et al. Seasonal and interannual changes in particulate organic carbon export and de- position in the Chukchi Sea. Journal of Geophysical Research, 2007, 112, C10024.

[10] S. B. Moran, R. P. Kelly, K. Hagstrom, J. Smith, et al. Seasonal changes in POC export flux in the Chukchi Sea and implications for water column-benthic coupling in Arctic shelves. Deep Sea Research Part II, 2005, 52: 3427-3451.

[11] S. B. Moran, J. N. Smith. 234Th as a tracer of scavenging and particle export in the Beaufort Sea. Continental Shelf Research, 2000, 20: 153-167.

[12] S. M. Trimble, M. Baskaran. The role of suspended particulate matter in 234Th scavenging and 234Th-derived export fluxes of POC in the Canada Basin of the Arctic Ocean. Marine Chemi- try, 2005, 96: 1-19.

[13] P. Cai, M. Dai, D. Lv and W. Chen. How accurate are 234Th measurements in seawater based on the MnO2-impregnated car- tridge technique. Geochemistry Geo-physics Geosystems, 2006, 7, Q03020.

[14] C. R. Benitez-Nelson, K. O. Buesseler, M. Rutgers van der Loeff, et al. Testing a new small-volume technique for determining 234Th in seawater. Journal of Radioanalytical and Nuclear Che- mistry, 2001, 248(3): 795-799.

[15] C. Benitez-Nelson, K. O. Buesseler, D. M. Karl and J. Andrews. A time-series study of particulate matter export in the North Pa- cific Subtropical Gyre based on 234Th:238U disequilibrium. Deep Sea Research Part I, 2001, 48: 2595-2611.

[16] K. O. Buesseler, C. Benitez-Nelson, M. R. Rutgers van der Lo- eff, et al. An intercomparison of small-and large-volume tech- niques for thorium-234 in seawater. Marine Chemistry, 2001, 74: 15-28.

[17] P. Cai, M. Dai, D. Lv and W. Chen. An improvement in the small-volume technique for deter-mining thorium-234 in sea- water. Marine Chemistry, 2006, 100: 282-288.

[18] S. M. Pike, K. O. Buesseler, J. A. Andrews and N. Savoye. Quantification of 234Th recovery in small volume sea water sam- ples by inductively coupled plasma-mass spectrometry. Journal of Radioanalytical and Nuclear Chemistry, 2005, 263(2): 355- 360.

[19] S. C. Tan, G. Y. Shi. Satellite-derived primary productivity and its spatial and temporal variability in China seas. Journal of Geo- graphical Sciences, 2006, 16(4): 447-457.

[20] R. W. Eppley, B. J. Peterson. Particulate organic matter flux and planktonic new production in the deep ocean. Nature, 1979, 282: 677-680.

[21] J. P. Gattuso, M. Frankignoulle and R. Wollast. Carbon and car- bonate metabolism in coastal aquatic ecosystems. Annual Re- view of Ecology and Systematics, 1998, 29: 405-434.

[22] K. O. Buesseler. Do upper-ocean sediment traps provide an accurate record of particle flux? Nature, 1991, 353: 420-423.

[23] M. P. Bacon, J. K. Cochran, D. Hirschberg, T. R. Hammar and A. P. Fleer. Export flux of carbon at the equator during the EqPac time-series cruises estimated from 234Th measurements. Deep Sea Research Part II, 1996, 43: 1133-1153.

[24] C. T. A. Chen. Chemical and physical fronts in the Bohai, Yel- low and East China seas. Journal of Marine Systems, 2009, 78: 394-410.

[25] J. H. Chen, R. L. Edwards and G. J. Wasserburg. 238U, 234U and 232Th in seawater. Earth and Planetary Science Letters, 1986, 80: 241-251.

[26] K. Buesseler, L. Ball, J. Andrews, et al. Upper ocean export of particulate organic carbon in the Arabian Sea derived from tho- rium-234. Deep-Sea Research Part II, 1998, 45: 2461-2487.

[27] K. O. Buesseler, J. A. Andrews, M. C. Hartman, R. Belastock and F. Chai. Regional estimates of the export flux of particulate organic carbon derived from thorium-234 during the JGOFS EqPac program. Deep Sea Research Part II, 1995, 42: 777-804.

[28] K. O. Buesseler, M. P. Bacon, J. K. Cochran and H. D. Living- ston. Carbon and nitrogen export during the JGOFS North At- lantic Bloom Experiment estimated from 234Th:238U disequili- bria. Deep Sea Research, 1992, 39: 1115-1137.

[29] K. O. Buesseler, C. R. Benitez-Nelson, S. B. Moran, et al. An assessment of particulate organic carbon to thorium-234 ratios in the ocean and their impact on the application of 234Th as a POC flux proxy. Marine Chemistry, 2006, 100: 213-233.

[30] P. Cai, W. Chen, M. Dai, et al. A high-resolution study of particle export in the southern South China Sea based on 234Th:238U dis- equilibrium. Journal of Geophysical Research, 2008, 113, C04019.

[31] W. F. Chen, P. H. Cai, M. H. Dai and J. F. Wei. 234Th/238U dis- equilibrium and particulate organic carbon export in the nor- thern South China Sea. Journal of Oceanography, 2008, 64: 417- 428.

[32] K. H. Coale, K. W. Bruland. 234Th:238U disequilibria within the California current. Limnology and Oceanography, 1985: 22-33.

[33] K. H. Coale, K. W. Bruland. Oceanic stratified euphotic zone as elucidated by 234Th:238U disequilibria. Limnology and Oceanog- raphy, 1987: 189-200.

[34] J. K. Cochran, P. Masqué. Short-lived U/Th series radionuclides in the ocean: tracers for scavenging rates, export fluxes and par- ticle dynamics. Uranium-Series Geochemistry, Reviews in Mineralogy and geochemistry, 2003, 52: 461-492.

[35] J. W. Murray, J. Young, J. Newton, J. Dunne, T. Chapin and B. Paul. Export flux of particulate organic carbon from the central equatorial Pacific determined using a combined drifting trap- 234Th approach. Deep Sea Research Part II, 1996, 43: 1095- 1132.

[36] N. Savoye, C. Benitez-Nelson, A. B. Burd, et al. 234Th sorption and export models in the water column: A review. Marine Che- mistry, 2006, 100: 234-249.

[37] J. T. Waples, C. Benitez-Nelson, N. Savoye, M. M. Rutgers van der Loeff, M. Baskaran and Ö. Gustafsson. An introduction to the application and future use of 234Th in aquatic systems. Ma- rine Chemistry, 2006, 100: 166-189.

[38] A. Knap, A. Michaels, A. Close, H. Ducklow and A. Dickson. Protocols for the Joint Global Ocean Flux Study (JGOFS) core measurements. JGOFS Report Nr. 19, 1996: vi-170 pp. (Reprint of the IOC Manuals and Guides No. 29, UNESCO 1994)

[39] X. M. Guo, Y. S. Zhang. Particle flux through the Huanghai Sea cold water mass. Acta Oceanologica Sinica, 2005, 24(5): 78-88.

[40] K. O. Buesseler. The decoupling of production and particulate export in the surface ocean. Global Biogeochemical Cycles, 1998, 12(2): 297-310.

[41] K. Zhou, S. Nodder, M. Dai and J. Hall. Insignificant enhancement of export flux in the highly productive Subtropical Front, east of New Zealand: A high resolution study of particle export fluxes based on 234Th:238U disequilibria. Bio-geosciences, 2012, 9: 973-992.

[42] S. H. Son, J. Campbell, M. Dowell, S. Yoo and J. Noh. Primary production in the Yellow Sea determined by ocean color remote sensing. Marine Ecology-Progress Series, 2005, 303: 91-103.

分享
Top