Variability of Climate and Carbon Sycling in the Tropical Pacific During Periods of Abrupt Thermocline Shift

摘要：根据该奖项，PI将试图了解从公元1800年至今热带太平洋温跃层环流的变化，并最终了解净CO2通量。 本文利用AMS（加速器质谱）技术对中热带太平洋帕尔米拉环礁（6 N，162 W）和热带东太平洋加拉帕戈斯群岛（0，91 W）的珊瑚带进行了高精度的放射性碳（DELTA ~（14）C ~+-2/mil）测量。 这项研究将提供ENSO和太平洋年代际振荡的历史记录。 它将使相关的新的14 C记录从加拉帕戈斯珊瑚在热带太平洋东部，揭示了一个显着的减少14 C在19世纪初，这表明了一个快速变化的来源沃茨涌上热带太平洋东部。 重要的是要知道19世纪初东太平洋表层14 C值的突然变化是局部事件还是广泛传播，即，延伸到太平洋中部 将通过与其他研究人员合作建立碳循环模型来确定从海洋表面这一广泛的过饱和区域到大气的二氧化碳年净通量的潜在影响。 这项研究解决了我们对过去气候变化及其对大气和海洋之间二氧化碳循环影响的认识中的根本差距。 这些结果将有助于我们了解气候的自然变化如何影响海洋吸收化石燃料和生物质燃烧产生的过量二氧化碳的能力。该补助金支持一名研究生和一名本科生，并提供实践经验，使他们为科学家和教育家的职业生涯做好准备。PI参与与初中和高中青年一起开展外联活动。

Abstract: Under this award the PI will try to understand changes in thermocline circulation and ultimately net CO2 fluxes in the tropical Pacific during the period AD 1800 to the present. High-precision radiocarbon (DELTA14C + - 2 per mil) measurements are proposed of annual and seasonal coral bands from Palmyra Atoll in the mid-tropical Pacific (6N, 162W) and Galapagos Islands in the eastern tropical Pacific (0, 91W) using AMS (accelerator mass spectrometry) techniques. This study will provide an historical record of ENSO and Pacific Decadal Oscillation. It will enable correlation with the new 14C record from Galapagos coral in the eastern tropical Pacific that reveals a prominent decrease of 14C during the early 1800s which indicates a rapid change in the source of waters upwelled in the eastern tropical Pacific. It is important to know whether the sudden shift in surface 14C values in the eastern ropical Pacific during the early 1800s was a local event or if it was wide-spread, i.e., extended into the mid-Pacific. Potential impact on the net annual flux of CO2 from this extensive supersaturated region of the surface ocean to the atmosphere will be determined by modeling of the carbon cycle in collaboration with other investigators. This study addresses fundamental gaps in our knowledge of past climate change and its influence on the cycling of CO2 between atmosphere and ocean. These results will aid in our understanding of how natural variability in climate can influence the ability of the ocean to absorb excess CO2 produced from fossil fuel and biomass burning. This grant supports a graduate student and an undergraduate student and provides hands-on experience that will prepare them for careers as scientists and educators. The PI is involved with developing outreach activities in conjunction with middle and high school youths.