Collaborative Research: Southern Ocean Iron Experiments (SOFeX)

OCE-9911481，OCE-0000364，OCE-0000365，OCE-0000363，OCE-0000362，OCE-0000361近年来，对海洋中溶解铁的研究和远洋富铁实验的结果表明，浮游植物的生长和生物量受到以溶解硝酸盐浓度高和叶绿素储量低为特征的水域中有效铁浓度的限制。20世纪90年代初，S在赤道东太平洋进行了开阔水域的开创性铁肥试验。从那时起，大量新的证据表明，在南极洲周围宽阔的向东流动的南大洋中，存在着一个更广泛的、具有全球意义的HNLS区域。在这个项目中，来自莫斯登陆海洋实验室、罗格斯大学、俄勒冈州立大学、迈阿密大学和拉蒙特-多尔蒂地球天文台的研究人员将在南冰洋170‘W的南极极锋带(APFZ)以北和以南地区进行一项开放水域的铁肥实验，该地区的主要营养物质含量高，溶解铁浓度极低。该小组将研究(1)富硅酸盐和贫硅酸盐HNLC水域中铁在生物泵中的作用，(2)铁对主要营养物质的差异下降的调节，(3)铁对表层水中碳固定和输出的限制，(4)对添加铁的生物物理响应，以及(5)铁诱导的碳输出对中水再矿化和反硝化的潜在影响。这项实地研究的基本假设是，南大洋浮游植物的生产速度和植物生物量在整个APFZ地区受到主要生长季节的有效性和硅酸盐有效性的不同限制，这是HNLC条件持续存在的原因。预计这项工作的结果将大大有助于我们对南大洋重要的生物地球化学过程的了解。控制新生产率的因素直接关系到全球碳循环、大气二氧化碳浓度和气候控制。这项位于APFZ南北的南大洋铁实验(SOFEX)将于2001-2002年夏季在南半球进行一次野外考察。

ABSTRACTOCE-9911481, OCE-0000364, OCE-0000365, OCE-0000363, OCE-0000362, OCE-0000361In recent years, studies of dissolved iron in the ocean and the results of open-ocean iron enrichments experiments have demonstrated that the growth and biomass of phytoplankton are limited by low concentrations of available iron in waters characterized by high concentrations of dissolved nitrate and low standing stocks of chlorophyll ("HNLC waters"). The seminal open-water iron fertilization experiments were done in the early 1990's in the eastern equatorial Pacific Ocean. Since that time, abundant new evidence has come to light that an even more extensive, and globally significant, HNLS region exists in the broad eastwardly flowing Southern Ocean surrounding Antarctica.In this project, researchers at the Moss Landing Marine Laboratory, Rutgers University, Oregon State University, University of Miami, and Lamont-Dougherty Earth Observatory will perform an open-water iron fertilization experiment in the Southern Ocean in regions just north of and just south of the Antarctic Polar Frontal Zone (APFZ) along 170'W, an area characterized by high major nutrients and extremely low dissolved iron concentrations. The team will investigate (1) the role of iron on the biological pump in silicate-rich versus silicate-poor HNLC waters, (2) iron mediation of differential drawdown of major nutrients, (3) iron limitation of carbon fixation and export from surface waters, (4) the biophysical response to added iron, and (5) the potential effect of iron-induced carbon export on midwater remineralization and denitrification. The underlying hypothesis driving this field study is that the rate of phytoplankton production and the quantity of plant biomass in the Southern Ocean are differentially limited across the APFZ by iton and silicate availability during the major growth season and are responsible for the persistence of the HNLC condition. The results of this work are expected to contribute significantly to our understanding of important biogeochemical processes in the Southern Ocean. Factors that control the rate of new production bear directly on the global carbon cycle, atmospheric carbon dioxide concentration, and climate control.This Southern Ocean Iron Experiment (SOFeX), north and south of the APFZ, will be carried out in a single field expedition in the austral summer of 2001-2002.