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

干旱-洪水周期，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的反应与显着的营养影响。最近的观察支持一个新的范式，气候主导营养富集在这些生态系统中，解释浮游植物的植物组成，生物量（叶绿素a），和初级生产（PP）的季节性和年际变化。该项目将通过量化对气候扰动的响应来评估美国两个最大河口--切萨皮克湾（CB）和阿尔伯马尔-帕姆利科湾-纽斯河口（APS-NRE）的这种范例。该项目将：（1）从气候强迫驱动的高变异性中解决浮游生物生物量/生产的长期趋势，例如产生显著偏离标准的干旱-洪水周期;（2）量化偶发性风和降水事件的作用，例如与锋面通道、热带风暴和飓风有关的事件，这些事件引起传统方法无法解决的生物量/生产的相应峰值。该实地项目将通过收集船上，飞机遥感和卫星（SeaWiFS，MODIS-A）数据，分析CB和APS-NRE的广泛监测数据以开发上下文，并量化气候扰动对浮游植物动态的影响，作为偏离长期平均值的浮游植物动态。快速响应取样将与利用基于区域海洋模拟系统的耦合水动力地球化学模型进行的数值模拟相结合。这种观察和建模的结合将被用来探索机械的联系和测试从现场数据获得的经验关系。智力优势。旱涝周期、热带风暴和飓风的严重性和频率都在增加，对陆地边缘生态系统造成了巨大压力。近五十年来，这些生态系统的研究和监测一直专注于富营养化。认识到气候扰动作为浮游植物变异的根本原因，代表着对这一单一焦点的重大偏离。该项目将联合收割机的观测和建模，以显着扩大我们的知识，气候如何调节河口浮游植物动态。在校准和验证水动力生态地球化学模型与CB和APS-NRE收集的数据，该项目的进展将导致预测能力，迄今尚未达到，使我们能够评估的范例，气候扰动调节河口浮游植物动态。更广泛的影响：解决气候扰动对河口浮游植物动态的影响，结合数据收集，分析和机械建模，对科学家和资源管理人员具有社会效益。此外，应用？基本的？在制定有效的养分管理战略时，科学界应考虑气候强迫因素。具体影响包括：（1）量化气候扰动对重要河口-海岸生态系统的生态过程的影响;（2）通过预测气候变化条件下的植物组成、叶绿素a和PP，将基于生态学的水质标准向前扩展;（3）结合观测和机制模型来支持情景分析，使我们能够区分长期趋势和气候变化。该项目将提供一个物理传输过程和浮游生物生产力的研究生课程，将受益于这项研究，支持两个博士学位。学生，并在NSF REU和少数民族外展计划在HPL-UMCES和IMS-ESTA培训本科生。主要产品将是同行评审的出版物和在科学会议上的发言。这三个主要研究员维护着用于分发结果和数据的活跃网站。

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.