Was Subantarctic Dust a Major Driver of Past CO2 Variability?

亚南极尘埃是过去二氧化碳变化的主要驱动因素吗？

• 批准号: 1405204
• 负责人: Gisela Winckler
• 金额: $ 39.85万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2019-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1405204&HistoricalAwards=false
• 关键词: Was; Subantarctic; Dust; Major; Driver

Intellectual Merit: The scarcity of iron in seawater can limit the amount of carbon exported from surface to deep waters in areas of the global ocean where the concentration of major nutrients is high, yet phytoplankton growth is low. Of these, the Southern Ocean is the region where variations in iron availability have the largest effect on Earth?s carbon cycle through its fertilizing effect on marine ecosystems. The PIs propose to measure biological productivity and dust flux at five sites spanning the breadth of the Subantarctic Pacific, including one high-resolution site to reconstruct variability of these parameters across abrupt climate change events. These reconstructions will allow the PIs to test whether or not variations in dust flux and changes in biological productivity are correlated in the Subantarctic Pacific as they are in the Subantarctic Atlantic. If they are, results will support current estimates of the iron fertilization effect on lowering CO2. However, if they do not find evidence for iron fertilization in the South Pacific, then the estimated impact of iron fertilization on ice-age CO2 cycles must be reduced and other non- iron fertilization related processes would need to be invoked to account for lower glacial CO2 levels. The results of this study could transform understanding of the role of the Southern Ocean in regulating atmospheric CO2.Broader impacts: This project will foster a strong international collaboration and will train a postdoctoral researcher and two undergraduate students. This research will assess the past response to natural variability of iron input in the largest sector of the Southern Ocean.

智力优势：在全球海洋主要营养物浓度高但浮游植物生长缓慢的地区，海水中铁的缺乏会限制从表层水向深层沃茨输出的碳量。其中，南大洋是铁可用性变化对地球影响最大的区域。通过其对海洋生态系统的破坏性影响来影响碳循环。研究所建议在横跨亚南极太平洋的五个地点测量生物生产力和尘埃通量，其中包括一个高分辨率地点，以重建这些参数在气候突变事件中的变异性。这些重建将使PI测试是否在沙尘通量和生物生产力的变化的变化是相关的，因为他们在亚大西洋亚大西洋亚大西洋。如果是这样，结果将支持目前对铁施肥降低二氧化碳排放效果的估计。然而，如果他们没有在南太平洋找到铁施肥的证据，那么铁施肥对冰河时期CO2循环的估计影响必须减少，并且需要调用其他非铁施肥相关过程来解释较低的冰川CO2水平。这项研究的结果可以改变对南大洋在调节大气CO2中的作用的理解。更广泛的影响：该项目将促进强有力的国际合作，并将培养一名博士后研究人员和两名本科生。这项研究将评估过去对南大洋最大部分铁投入自然变化的反应。