Constraining Upper-Ocean Carbon Export with Biogeochemical Profiling Floats

化学海洋学的一个目标是促进我们对全球碳循环的理解，特别是通过海洋生物产生的颗粒下沉来量化碳从表层海洋向深海的转移。然而，现代全球对这一过程(通常称为碳出口)的估计相差超过100%。这些估计通常是根据海洋测量和卫星观测之间的区域关系得出的，然后在全球范围内应用。在整个海洋中都发现了卫星和现场对碳出口的估计之间的持续差异，这表明需要改进。该项目将确定是否可以使用配备化学传感器的剖面浮标来估计海洋中的碳出口。浮动车将部署在海洋站Papa，但这种方法本质上是可扩展的，可以用于验证和改进用于全球碳出口测定的卫星算法。该项目将支持一名女性早期职业科学家和一名博士后，并促进与加拿大科学家的国际合作。此外，这一结果可能有助于美国国家航空航天局(美国航天局)的出口活动以及其他卫星碳出口的发展努力。现代全球对生物泵的估计相差超过100%(~5至12pgCyr-1)，这使得确定海洋生物地球化学(BGC)循环在现代气候和气候变异性中的作用具有挑战性。全球碳出口估计值通常是根据实地观测和卫星观测之间的区域经验关系得出的，然后在全球范围内应用。独特的卫星算法和独特的地球化学方法之间的持续差异表明，准确量化生物泵仍然是一个基本的研究目标。该项目将评估使用BGC剖面浮标估计不同生物碳库(溶解和颗粒有机碳，以及颗粒无机碳)出口的能力。通过使用BGC浮标关闭多个上层海洋示踪剂预算，该项目将解决其他地球化学方法常见的两个已知问题：关于(1)溶解有机碳循环和(2)用于年度碳出口评估的整合深度的假设。该方法将在PAPA海洋站进行测试，但在性质上是可扩展的，可用于开发一个碳出口数据库，用于验证和培训确定全球碳出口所需的卫星算法。浮标的结果将与卫星碳输出算法在5年浮标寿命内的估计进行比较。来自该地区浮标和系泊的十年现有BGC数据也将被用来提供关于年际变化的进一步背景。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

A goal in chemical oceanography is to advance our understanding of the global carbon cycle, specifically to quantify the transfer of carbon from the surface ocean to depth through the sinking of particles produced by marine organisms. Yet, modern global estimates of this process (commonly called carbon export) differ by over 100%. These estimates are often derived from regional relationships between ocean measurements and satellite observations that are then applied globally. Persistent differences between the satellite and field-based estimates of carbon export have been found throughout the ocean, suggesting that improvements are needed. This project will determine whether profiling floats equipped with chemical sensors can be used to estimate the export of carbon in the ocean. Floats will be deployed at Ocean Station Papa, but the approach is scalable in nature and could be used to validate and improve the satellite algorithms used for global carbon export determinations. The project will support a female, early career scientist and a postdoc, as well as facilitate international collaboration with Canadian scientists. Additionally, the results may assist the National Aeronautics and Space Administration (NASA) EXPORTS campaign as well as other satellite carbon export development efforts. Modern global estimates of the biological pump differ by over 100% (~5 to 12 Pg C yr-1) making it challenging to determine the role of marine biogeochemical (BGC) cycling in modern climate and climate variability. Global carbon export estimates are often derived from regional empirical relationships between field and satellite observations that are then applied globally. Persistent discrepancies between unique satellite algorithms and unique geochemical approaches suggest that accurately quantifying the biological pump remains a fundamental research goal. This project will assess the capability of using BGC profiling floats to estimate the export of distinct biogenic carbon pools (dissolved and particulate organic carbon, and particulate inorganic carbon). By using BGC floats to close multiple upper ocean tracer budgets this project will address two known issues common to other geochemical approaches: assumptions about (1) dissolved organic carbon cycling and (2) the integration depth used for annual carbon export assessments. The method will be tested at Ocean Station Papa, but is scalable in nature and could be used to develop a carbon export database suitable for the validation and training of satellite algorithms required for global carbon export determinations. Results from the floats will be compared to satellite carbon export algorithm estimates over the 5-year float lifetimes. Ten years of existing BGC data from profiling floats and a mooring in the region will also be used to provide further context about interannual variability.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.