IPY: Shedding dynamic light on iron limitation: The interplay of iron limitation and dynamic irradiance in governing the phytoplankton distribution in the Ross Sea

IPY：揭示铁限制的动态亮点：铁限制和动态辐照度在控制罗斯海浮游植物分布中的相互作用

• 批准号: 0732535
• 负责人: Kevin Arrigo
• 金额: $ 58.74万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-10-01 至 2010-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0732535&HistoricalAwards=false
• 关键词: IPY; Shedding; dynamic; light; iron

0732535 - Arrigo, Kevin - Stanford UniversityIPY: Shedding dynamic light on iron limitation: The interplay of ironlimitation and dynamic irradiance in governing the phytoplanktondistribution in the Ross SeaThe Southern Ocean plays an important role in the global carbon cycle, accounting for approximately 25% of total anthropogenic CO2 uptake by the oceans, mainly via primary production. In the Ross Sea, primary production is dominated by two taxa that are distinct in location and timing. Diatoms dominate in the shallow mixed layer of the continental shelf, whereas the colony forming Phaeocystis antarctica (Prymnesiophyceae) dominate in the more deeply mixed, open regions. Significantly, both groups have vastly different nutrient utilization characteristics, and support very different marine food webs. Their responses to climate change, and the implications for carbon export, are unclear. Previous studies show that light availability and the quality of the light climate (static versus dynamic) play a major role in defining where and when the different phytoplankton taxa bloom. However, iron (Fe) limitation of the algal communities in both the sub-Arctic and the Southern Ocean is now well documented. Moreover, phytoplankton Fe demand varies as a function of irradiance. The main hypothesis of the proposed research is: The interaction between Fe limitation and dynamic irradiance governs phytoplankton distributions in the Ross Sea. Our strategy to test this hypothesis is three-fold: 1) The photoacclimation of the different phytoplankton taxa to different light conditions under Fe limitation will be investigated in experiments in the laboratory under controlled Fe conditions. 2) The photophysiological mechanisms found in these laboratory experiments will then be tested in the field on two cruises with international IPY partners. 3) Finally, data generated during the lab and field parts of the project will be used to parameterize a dynamic light component of the Coupled Ice Atmosphere and Ocean (CIAO) model of the Ross Sea. Using the improved model, we will run future climate scenarios to test the impact of climate change on the phytoplankton community structure, distribution, primary production and carbon export in the Southern Ocean. The proposed research complies with IPY theme" Understanding Environmental change in Polar Regions" and includes participation in an international cruise. Detailed model descriptions and all of the results generated from these studies will be made public via a DynaLiFe website. Improving the CIAO model will give us and other IPY partners the opportunity to test the ecological consequences of physiological characteristics observed in Antarctic phytoplankton under current and future climate scenarios. Outreach will include participation in Stanford's Summer Program for Professional Development for Science Teachers, Stanford's School of Earth Sciences high school internship program, and development of curriculum for local science training centers, including the Chabot Space and Science Center.

0732535 - Arrigo，Kevin -斯坦福大学IPY：对铁限制的动态光：铁限制和动态辐照度在控制罗斯海的植物分布中的相互作用南大洋在全球碳循环中发挥着重要作用，占海洋人为CO2吸收总量的约25%，主要通过初级生产。在罗斯海，初级生产主要由两个类群，这是不同的位置和时间。 硅藻占主导地位的浅混合层的大陆架，而殖民地的殖民地形成Phaeocystis anarctica（Prymnesiophyceae）占主导地位的更深的混合，开放的地区。值得注意的是，这两个群体具有截然不同的营养利用特征，并支持非常不同的海洋食物网。 它们对气候变化的反应以及对碳出口的影响尚不清楚。 以前的研究表明，光的可用性和光气候的质量（静态与动态）在定义不同的浮游植物类群何时何地开花方面发挥着重要作用。然而，铁（Fe）的限制，在亚北极和南大洋的藻类群落，现在是有据可查的。此外，浮游植物的铁需求变化的函数的辐照度。 研究的主要假设是：Fe限制和动态辐照度之间的相互作用决定了罗斯海浮游植物的分布。 我们检验这一假设的策略有三个方面：1）在实验室控制铁条件下，研究不同浮游植物类群在铁限制下对不同光照条件的光适应。2)在这些实验室实验中发现的生理机制将在与国际海洋年合作伙伴的两次航行中进行实地测试。3)最后，该项目的实验室和现场部分产生的数据将用于罗斯海耦合冰大气和海洋（CIAO）模型的动态光组件的参数化。利用改进后的模型，我们将运行未来的气候情景，以测试气候变化对南大洋浮游植物群落结构，分布，初级生产和碳输出的影响。拟议的研究符合国际极地年的主题”了解极地地区的环境变化”，并包括参加一次国际巡航。 详细的模型描述和这些研究产生的所有结果将通过DynaLiFe网站公开。改进CIAO模型将使我们和其他IPY合作伙伴有机会测试在当前和未来气候情景下南极浮游植物中观察到的生理特征的生态后果。外联活动将包括参与斯坦福大学的科学教师专业发展暑期项目、斯坦福大学地球科学学院的高中实习项目，以及为当地科学培训中心（包括Chabot空间和科学中心）制定课程。