Collaborative Research: Regulation of Phytoplankton Dynamics in Mid-Atlantic Estuaries Subject to Climatic Perturbations.

干旱-洪水循环、热带风暴和飓风的气候扰动在大西洋中部河口越来越重要，导致浮游生物系统的生态系统规模响应，具有重要的营养意义。最近的观察结果支持一种新的范式，即气候主导着这些生态系统中的营养物质丰富，解释了浮游植物区系组成、生物量(Chl-a)和初级生产力(PP)的季节和年际变化。该项目将在美国最大的两个河口，切萨皮克湾(CB)和Albemarle-Pamlico Sound-Neuse河口(APS-NRE)通过量化对气候扰动的响应来评估这一范例。该项目将：(1)解决由气候强迫驱动的高变异性造成的浮游生物生物量/生产量的长期趋势，例如造成显著偏离常态的旱涝循环；(2)量化与锋面通道、热带风暴和飓风有关的间歇性风和降水事件的作用，这些事件引起生物量/生产量的相应高峰，而不是传统方法的解决办法。该实地计划将通过收集船上、飞机遥感和卫星(SeaWiFS，MODIS-A)数据，分析CB和APS-NRE的广泛监测数据来发展背景，并量化气候扰动对浮游植物动力学的影响，从而量化气候扰动对浮游植物动力学的影响。快速反应采样将与使用基于区域海洋模拟系统(ROMS)的耦合水动力生物地球化学模型的数值模拟配对。这种观察和建模的结合将被用来探索机械联系，并检验从现场数据获得的经验关系。智力上的功绩。旱涝循环、热带风暴和飓风的发生日益严重和频繁，给陆地边缘生态系统带来了巨大压力。近50年来，对这些生态系统的研究和监测一直集中在富营养化问题上。认识到气候扰动是浮游植物变异性的根本原因，这是对这一单一关注点的重大偏离。这个项目将结合观测和建模来显著扩展我们对气候如何调节河口浮游植物动态的知识。该项目在利用CB和APS-NRE收集的数据校准和验证水动力生物地球化学模型方面的进展将导致迄今尚未达到的预测能力，使我们能够评估气候扰动调节河口浮游植物动态的范式。更广泛的影响：通过数据收集、分析和机械建模相结合的方法解决气候扰动对河口浮游植物动态的影响，对科学家和资源管理人员具有社会效益。除基本应用外的其他应用科学包括在设计有效的营养管理策略时考虑气候强迫。具体影响包括：(1)量化气候扰动对重要河口-沿海生态系统浮游过程的影响；(2)通过能够在变化的气候条件下预测植物组成、Chl-a和PP，向前扩展基于经验的水质标准；(3)将观测和机械模型结合起来支持情景分析，使我们能够区分长期趋势和气候施加的变异性。该项目将提供一门物理运输过程和浮游生物生产力的研究生课程，将从这项研究中受益，支持两名博士生，并在HPL-UMCES和IMS-UNC培训NSF REU和少数族裔外联计划的本科生。主要产品将是同行评议的出版物和在科学会议上的陈述。这三个PI维持着活跃的网站，这些网站将被用来分发结果和数据。

Climatic perturbations by drought-flood cycles, tropical storms, and hurricanes are increasingly important in Mid-Atlantic estuaries, leading to ecosystem-scale responses of the plankton system with significant trophic implications. Recent observations support an emerging paradigm that climate dominates nutrient enrichment in these ecosystems, explaining seasonal and interannual variability of phytoplankton floral composition, biomass (chl-a), and primary production (PP). This project will evaluate this paradigm in the two largest estuaries in the United States, Chesapeake Bay (CB) and Albemarle-Pamlico Sound-Neuse River Estuary (APS-NRE) by quantifying responses to climatic perturbations. This project will: (1) resolve long-term trends of plankton biomass/production from high variability driven by climatic forcing, such as drought-flood cycles that generate significant departures from the norm; (2) quantify the role of episodic wind and precipitation events, such as those associated with frontal passages, tropical storms, and hurricanes, that evoke consequential spikes of biomass/production outside the resolution of traditional methods. The field program will focus on event-scale forcing of phytoplankton dynamics by collecting shipboard, aircraft remote sensing, and satellite (SeaWiFS, MODIS-A) data, analyzing extensive monitoring data for CB and APS-NRE to develop context, and quantifying effects of climatic perturbations on phytoplankton dynamics as departures from long-term averages. The rapid-response sampling will be paired with numerical simulations using coupled hydrodynamic biogeochemical models based on the Regional Ocean Modeling System (ROMS). This combination of observations and modeling will be used to explore mechanistic links and test empirical relationships obtained from field data. Intellectual Merit. Drought-flood cycles, tropical storms, and hurricanes are occurring at increasing severity and frequency, exerting significant pressures on land margin ecosystems. Research and monitoring in these ecosystems has focused singularly on eutrophication for nearly five decades. Recognition of climatic perturbations as the underlying cause of phytoplankton variability represents a significant departure from this singular focus. This project will combine observations and modeling to significantly extend our knowledge of how climate regulates phytoplankton dynamics in estuaries. Progress in calibrating and validating hydrodynamic biogeochemical models with data collected in CB and APS-NRE by this project will lead to predictive capabilities thus far unattained, allowing us to evaluate the paradigm that climatic perturbations regulate phytoplankton dynamics in estuaries. Broader Impacts: Addressing the effects of climatic perturbations on phytoplankton dynamics in estuaries with a combination of data collection, analysis, and mechanistic modeling has societal benefits for scientists and resource managers. Applications in addition to ?basic? science include the consideration of climatic forcing in designing effective nutrient management strategies. Specific impacts include: (1) quantifying the effects of climatic perturbations on planktonic processes for important estuarine-coastal ecosystems; (2) extending empirically-based water quality criteria forward by enabling predictions of floral composition, chl-a, and PP in changing climate conditions; (3) combining observations and mechanistic models to support scenario analysis, allowing us to distinguish long-term trends from variability imposed by climate. This project will offer a graduate course in physical transport processes and plankton productivity that will benefit from this research, support two Ph.D. students, and train undergraduates in NSF REU and minority outreach programs at HPL-UMCES and IMS-UNC. The main products will be peer-reviewed publications and presentations at scientific meetings. The three PIs maintain active web sites that will be used to distribute results and data.