A power law model of dynamic marine phytoplankton stoichiometry

大约一个世纪以前，阿尔弗雷德·雷德菲尔德观察到，海洋浮游植物中碳、氮、磷元素的比例在整个海洋中几乎是相同的。这一观察结果后来被称为“雷德菲尔德比率”，是生物和化学海洋学的核心思想。雷德菲尔德比值提供了一种方便和有用的方法来联系营养物（氮和磷）和碳的吸收，并探索海洋碳循环的各个方面。然而，最近的工作强调了碳氮磷（C:N:P）比例变化的多种方式，这表明它们不变的简单假设应该重新审视。该项目的总体目标是开发一种方法，将不同的C:N:P比率纳入海洋模型，使研究人员能够探索这些变化对碳循环的影响。拟议的工作将直接支持研究生研究人员，并包括STEM向当地学校的推广。该项目将开发一个灵活的浮游植物化学计量学的幂律模型，这种方法能够捕捉到元素比例作为多种环境驱动因素的函数的非线性行为。幂律模型的核心特征是一个系数，它可以产生关于浮游植物生物化学（即浮游植物动态平衡）和海洋生物地球化学（即全球碳输出生产对环境变化的缓冲能力）的有用见解。此外，幂律模型在数学上是稳健的，因此很容易移植到全球海洋模型中。幂律模型的这些属性有望促进利用全球海洋模型进行的动力化学计量学的广泛研究。研究人员还将利用他们的新化学计量模型建立两个全球海洋模型，并量化在持续的全球变暖和晚更新世冰期条件下的化学计量-生物地球化学循环-气候反馈。因此，这项研究将对化学海洋学作出重大贡献，因为它开发了一种新的方法来表示海洋模式中的化学计量多样性，并通过量化这种多样性在不同气候条件下的全球影响。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Almost a century ago, Alfred Redfield observed that the ratios of the elements carbon, nitrogen, and phosphorus in ocean phytoplankton were nearly the same throughout the oceans. This observation came to be called the "Redfield ratio" and is a central idea in biological and chemical oceanography. The Redfield ratio provides a convenient and useful way of relating the uptake of nutrients (nitrogen and phosphorus) and carbon, and of exploring aspects of ocean carbon cycling. Recent work, however, has highlighted the many ways in which the carbon to nitrogen to phosphorus (C:N:P) ratios can vary, suggesting that the simple assumption that they are unchanging should be revisited. The overall goal of this project is to develop a way of incorporating varying C:N:P ratios into ocean models that will allow researchers to explore the impacts of these variations on carbon cycling. The proposed work will directly support graduate student researchers and include STEM outreach to local schools. This project will develop a power law model of flexible phytoplankton stoichiometry, an approach that is able to capture the nonlinear behavior of the elemental ratios as a function of multiple environmental drivers. The central feature of the power law model is a coefficient that yields useful insights about phytoplankton biochemistry (i.e., phytoplankton homeostasis) and ocean biogeochemistry (i.e., the buffer capacity of the global carbon export production to environmental changes). Furthermore, the power law model is mathematically robust and thus easily ported to global ocean models. These attributes of the power law model are expected to facilitate widespread studies of dynamic stoichiometry with global ocean models. The investigators will also enable two global ocean models with their new stoichiometry model and quantify the stoichiometry-biogeochemical cycles-climate feedbacks under ongoing global warming and late Pleistocene ice age conditions. This study will thus make a significant contribution to chemical oceanography by developing a new approach to representing stoichiometric diversity in ocean models and by quantifying the global impacts of that diversity under different climate conditions.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.