OCE-PRF: Do wildfires drive phytoplankton blooms in the California Current System?

在过去的50年里，美国西海岸野火的频率和空间范围都大大增加了。火灾的结果是，大量的火山灰、黑碳和其他气溶胶被注入大气，并从燃烧区域转移到海洋表面。尽管地理位置靠近大火，但人们对这些生物质燃烧副产品的沉积如何影响加州洋流系统（CCS）附近的海洋生态系统知之甚少。该项目将利用卫星、现场和历史数据，以及二维理想化和三维现实模型进行调查。如果野火确实在CCS中引起了水华，可能会对地下缺氧和酸化产生影响，这可能会反馈到更高的营养水平。本项目提出的工作将有助于提高对陆地-海洋系统之间反馈的理解，这可以进一步用于IPCC评估未来气候强迫对CCS和其他大型野火沿海系统的影响。这项工作可能对海洋保护区的长期管理也很重要。PI是第一代大学生，也是一名有色人种女性，她将成为海洋科学界的一个明显的榜样，指导UCSC的本科生和研究生研究人员，从事客座讲座和教学，帮助促进历史上边缘化群体的学生的保留，并参与当地的外拓展活动，与社区和有抱负的年轻科学家在UCSC的西摩海洋探索中心进行接触。这个项目的一个主要假设是，由于营养和铁的施肥，灰沉积的一级效应驱动了强烈的浮游植物繁殖。目标是：(1)确定CCS中野火引起的水华的存在；(2)通过模型中的灰烬沉积参数化野火强迫；(3)提供对生态系统响应的机制理解。在加州大学圣克鲁斯分校的导师克里斯托弗·爱德华兹博士的指导下，该项目将结合大气和海洋观测数据集，首先确定已观测到的生物质燃烧对海洋生态系统的影响。为了进一步从观测工作中得到结果，理想化的二维模型将用于创建一个新的野火参数化，以了解生态系统的响应。最后，高分辨率3D模型将用于在现实框架中调查2017/2018年野火季节。总的来说，该项目将提供定量评估和简单的理论来解释生态系统对生物质燃烧的反应。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。

The frequency and spatial extent of wildfires along the US West Coast has substantially increased over the last fifty years. As a consequence of fire, large plumes of ash, black carbon, and other aerosols are injected into the atmosphere and transported away from burn areas where they often land on the surface of the ocean. Despite the geographical proximity to large fires, there is little understanding of how the deposition of these byproducts of biomass burning affects the nearby marine ecosystem in the California Current System (CCS). This project would investigate, using satellite, in-situ and historical data, and 2-D idealized and 3-D realistic modeling. If wildfires indeed induce blooms in the CCS, there are likely impacts on subsurface hypoxia and acidification, which can feed back into higher trophic levels. The efforts proposed in this project will facilitate improved understanding of the feedbacks between the terrestrial-ocean system, which can further be used to inform IPCC assessments of the impacts of future climate forcing on the CCS and other coastal systems with large wildfires. This work may additionally be important for the long-term management of marine protected areas. The PI is a first-generation college student and a woman of color, who will serve as a visible role model within the ocean sciences community, mentor undergraduate students and graduate researchers at UCSC, engage in guest lecturing and teaching, to help promote the retention of students from historically marginalized groups, and participate in local outreach events to engage with the community and aspiring young scientists at UCSC's Seymour Marine Discovery Center.A major hypothesis in this project is that the first order effects from ash deposition drive strong phytoplankton blooms as a consequence of nutrient and iron fertilization. Goals are to: (1) identify the presence of wildfire induced blooms in the CCS, (2) parameterize wildfire forcing through ash deposition in models, and (3) provide a mechanistic understanding of ecosystem responses. With mentor Dr. Christopher Edwards at the University of California – Santa Cruz, the project would use a combination of atmospheric and oceanic observational data sets to first identify the observed impact of biomass burning on the marine ecosystem. To further the results from the observational work, idealized 2D modeling will be used to create a new wildfire parameterization to understand ecosystem responses. Finally, high resolution 3D models will be used to investigate the 2017/2018 wildfire season in a realistic framework. Overall, the project will provide quantitative assessments and simple theories explaining the ecosystem responses to biomass burning.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.