US GEOTRACES GP17-OCE and GP17-ANT: Inorganic Carbon Cycling in the South Pacific and Southern Oceans by Direct Measurement

海洋通过吸收化石燃料燃烧和其他人类活动产生的约四分之一的二氧化碳（CO2）来帮助减缓气候变化。众所周知，太平洋和南大洋吸收和储存了大量的人为CO2，但有关数量，变化以及地球化学和生态影响的许多问题仍然没有答案。这项研究将侧重于回答太平洋两个地区的一些问题，通过分析两个GEOTRACES游轮GP 17-OCE和GP 17-ANT的总CO2，总碱度和pH值样本。 该项目将支持几名本科生研究人员，并为公众和K-12学生创建关于海洋酸化的教育模块。将通过比较这次考察收集的数据与1991年以前占领该线的数据，2005年和2014年。将使用扩展的多元线性回归技术将自然变异性与人为引起的变化分开。第二次探险，GP 17-ANT，覆盖阿蒙森海，一个以前很少进行碳测量的地区。这片海域常年被冰雪覆盖，有几个季节性的冰穴（被海冰包围的开放水域），水循环复杂，对全球碳循环的贡献不确定。从这次考察收集的数据将研究关于碳如何在该地区被吸收，混合和再循环的几种假设，冰川融化，海冰和生物生产力如何影响碳循环，并提供基线测量未来的数据，以确定该地区碳循环随时间的变化。这两个考察将利用无数的其他参数被测量，特别是微量金属，如铁和锌，研究如何循环的碳和微量金属是通过pH值相互关联的。这个奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

The oceans help to slow climate change by absorbing about a quarter of the carbon dioxide (CO2) produced by burning of fossil fuels and other human activities. The Pacific and Southern Oceans are known to take up and store significant amounts of anthropogenic CO2, but many questions regarding the amount, variability, and biogeochemical and ecological impacts remain unanswered. This research will focus on answering some of those questions in two areas of the Pacific by analyzing samples for total CO2, total alkalinity, and pH on two GEOTRACES cruises, GP17-OCE and GP17-ANT. The project will support several undergraduate student researchers and create educational modules on ocean acidification for general public and K-12 students.On the GP17-OCE expedition in the south Pacific, sub-decadal scale variability in the uptake of CO2 and resulting decrease in pH (termed ocean acidification) will be examined by comparing data collected on this expedition with data from prior occupations of the line in 1991, 2005 and 2014. An extended multilinear regression technique will be used to separate natural variability from human induced changes. The second expedition, GP17-ANT, covers the Amundsen Sea, an area with few prior carbon measurements. This sea is perennially ice-covered with several seasonal polynyas (areas of open water surrounded by sea ice) and exhibits complex water circulation making the contribution to the global carbon cycle uncertain. The data collected from this expedition will examine several hypotheses regarding how carbon is taken up, mixed, and recirculated in the region, how glacial ice melt, sea ice, and biological productivity influence the carbon cycle, and provide baseline measurements against future data to determine changes in the carbon cycle of the region over time. Both expeditions will leverage the myriad of other parameters being measured, particularly trace metals such as iron and zinc, to examine how cycling of carbon and trace metals are interlinked through pH.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.