Southern Ocean Iron Enrichment Experiment: Carbon Cycling in High- and Low-Si Waters

• Published in: Science (American Association for the Advancement of Science) Vol. 304; no. 5669; pp. 408 - 414
• Main Authors: Coale, Kenneth H., Johnson, Kenneth S., Chavez, Francisco P., Buesseler, Ken O., Barber, Richard T., Brzezinski, Mark A., Cochlan, William P., Millero, Frank J., Falkowski, Paul G., Bauer, James E., Wanninkhof, Rik H., Kudela, Raphael M., Altabet, Mark A., Hales, Burke E., Takahashi, Taro, Landry, Michael R., Bidigare, Robert R., Wang, Xiujun, Chase, Zanna, Strutton, Pete G., Friederich, Gernot E., Gorbunov, Maxim Y., Lance, Veronica P., Hilting, Anna K., Hiscock, Michael R., Demarest, Mark, Hiscock, William T., Sullivan, Kevin F., Tanner, Sara J., Gordon, R. Mike, Hunter, Craig N., Elrod, Virginia A., Fitzwater, Steve E., Jones, Janice L., Tozzi, Sasha, Koblizek, Michal, Roberts, Alice E., Herndon, Julian, Brewster, Jodi, Ladizinsky, Nicolas, Smith, Geoffrey, Cooper, David, Timothy, David, Brown, Susan L., Selph, Karen E., Sheridan, Cecelia C., Twining, Benjamin S., Johnson, Zackary I.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 16.04.2004; The American Association for the Advancement of Science
• Subjects: Atmosphere; Atmospherics; Bacillariophyceae; Biomass; Carbon - analysis; Carbon - metabolism; Carbon cycle; Carbon cycle (Biogeochemistry); Carbon dioxide; Carbon Dioxide - analysis; Carbon Dioxide - metabolism; Chemical properties; Chlorophyll - analysis; Diatoms; Diatoms - growth & development; Diatoms - metabolism; Earth sciences; Earth, ocean, space; Ecosystem; Environmental conditions; Exact sciences and technology; Experiments; External geophysics; Geochemistry; Iron; Iron - analysis; Iron - metabolism; Marine; Measurement; Mineralogy; Nitrates; Nitrates - analysis; Nitrates - metabolism; Nitrogen - analysis; Nitrogen - metabolism; Ocean circulation; Oceanography; Oceans; Oceans and Seas; Photosynthesis; Physical and chemical properties of sea water; Physics of the oceans; Phytoplankton; Phytoplankton - growth & development; Phytoplankton - metabolism; Ratios; Sea water; Seawater - chemistry; Silicates; Silicic Acid - analysis; Silicic Acid - metabolism; Surface water; Water geochemistry; Southern Ocean; United States; Antarctic Ocean; PS, Antarctic Ocean; Sea surface; Addition; Primary productivity; Silicic acid; Algae; Carbon dioxide; Environmental factor; Iron; Biogeochemical cycle; Experimental study; Carbon cycle; Micronutrient; Heterokontophyta; Inorganic acids; Biogeochemistry; Bacillariophyta; Air sea interface; Mesoscale; Phytoplankton; Thallophyta
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1089778

The availability of iron is known to exert a controlling influence on biological productivity in surface waters over large areas of the ocean and may have been an important factor in the variation of the concentration of atmospheric carbon dioxide over glacial cycles. The effect of iron in the Southern Ocean is particularly important because of its large area and abundant nitrate, yet iron-enhanced growth of phytoplankton may be differentially expressed between waters with high silicic acid in the south and low silicic acid in the north, where diatom growth may be limited by both silicic acid and iron. Two mesoscale experiments, designed to investigate the effects of iron enrichment in regions with high and low concentrations of silicic acid, were performed in the Southern Ocean. These experiments demonstrate iron's pivotal role in controlling carbon uptake and regulating atmospheric partial pressure of carbon dioxide.