RAPID: Collaborative Research: Unprecedented Hurricane Ian Nutrient and Organic Matter Inputs to Southwest Florida Coastal Waters

许多沿海系统正面临着持续发展和气候变化的威胁，包括飓风等极端天气事件的强度增加。现在这样的风暴比前几年更潮湿，因为温暖的大气中含有更多的水分。因此，它们释放更多的降雨，向沿海地区输送更多的营养物质和有机物质。这反过来又导致浮游植物大量繁殖，有可能形成区域性的“死区”或溶解氧很少或没有溶解氧的地区。飓风伊恩是2022年9月下旬袭击佛罗里达州西南部的4级飓风，给沿海河口和佛罗里达州西南部大陆架水域带来了巨大的营养和有机碳输入，这为研究一场大风暴扰动对沿海系统的影响提供了机会，该系统正处于不断增加的沿海营养压力之下。这个RAPID项目的目标是检查从河口到低营养大陆架水域的梯度站的碳和营养循环，以确定该系统的变化和恢复速度，以及大型飓风输入与缺氧、缺氧和海洋酸化的关系。这些数据被用来开发一个区域模型来预测未来飓风对海洋酸化、浮游植物大量繁殖以及当地缺氧和缺氧的影响。这项研究利用了由州和联邦管理机构资助的持续监测项目，以及nsf支持的本科生项目。它为培养博士后研究人员和研究生提供部分支持。拓展活动将包括对小学生和中学生的演讲。2022年9月，佛罗里达州西南部遭受了4级飓风“伊恩”的直接袭击，导致广泛的流域洪水和富含营养物质和溶解有机物的河口羽流延伸超过50英里，一直延伸到营养不良的西佛罗里达大陆架（WFS）。大量的陆地有机碳和营养物质输入到佛罗里达西南海岸和大陆架地区，可能为这种寡营养系统提供了广泛的浮游植物繁殖，以及碳化学和营养循环的重大变化，可能导致长期的区域缺氧和缺氧。在这个RAPID项目中，研究人员将于2022年12月、2023年2月和2023年9月在夏洛特港和邻近的内WFS系统的站点测量一套碳和养分参数，以及碳和养分循环。目标是评估：1)系统反应的时间尺度，从较短的（几周到几个月）到飓风后一年的影响；2)营养物质的有效性和形态如何影响缺氧；3)飓风驱动的输入如何影响该系统中的碳酸盐化学，特别是酸化和缺氧之间的联系。研究人员正在使用这项研究中收集的新数据，并在一个耦合的水动力学-生物地球化学模型中监测来自地区州和联邦项目的数据，以了解WFS的条件。预测模拟和模拟实验正在评估大量养分和有机物的输入如何影响浮游植物、氧条件和碳化学。模拟实验正在探索不同风和降水强度的风暴如何影响WFS和河口，确定WFS从偶发性缺氧转变为持续性缺氧的临界点。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。

Many coastal systems are facing the threats of continuing development and climate change, including an increased intensity of extreme weather events such as hurricanes. Such storms are now wetter than in prior years because warmer atmospheres hold more moisture. Thus, they release more rainfall and deliver more nutrients and organic matter to coastal areas. This, in turn, leads to phytoplankton blooms with potential for regional “dead zones” or areas with little or no dissolved oxygen. Hurricane Ian, a category 4 hurricane which hit southwest Florida in late September 2022, resulted in immense nutrient and organic carbon inputs to the coastal estuaries and southwest Florida shelf waters and presents an opportunity to examine the effects of a major storm disturbance on a coastal system that is under increasing coastal nutrient stress. The objective of this RAPID project is to examine carbon and nutrient cycling along a gradient of stations from the estuary to low-nutrient shelf waters to determine the rate of change and recovery in this system and the relationship of large hurricane inputs to hypoxia, anoxia, and ocean acidification. These data are being used to develop a regional model to predict the impact of future hurricanes on ocean acidification, phytoplankton blooms, and local hypoxia and anoxia. This study leverages ongoing monitoring programs funded by state and federal management agencies, as well as NSF-supported programs for undergraduate students. It provides partial support for training of postdoctoral investigators and a graduate student. Outreach will include presentations to elementary and high school students.In September 2022, southwest Florida experienced a direct hit from category-4 Hurricane Ian, resulting in extensive watershed flooding and nutrient- and dissolved-organic-matter-laden estuarine plumes extending more than 50 miles onto the shallow oligotrophic west Florida shelf (WFS). The massive terrestrial organic carbon and nutrient inputs to the southwest Florida coastal and shelf region may be priming this oligotrophic system for extensive phytoplankton blooms, as well as significant changes in carbon chemistry and nutrient cycling that could lead to longer-term regional hypoxia and anoxia. In this RAPID project, the investigators are measuring a suite of carbon and nutrient parameters, as well as carbon and nutrient cycling, at stations in Charlotte Harbor and the adjacent inner WFS system in December 2022, February 2023, and September 2023. The objectives are to assess: 1) a timescale of system responses from shorter (weeks to months) to 1-year impacts post-hurricane; 2) how nutrient availability and forms influence hypoxia; and 3) how hurricane-driven inputs influence carbonate chemistry in this system, specifically the connection between acidification and hypoxia. The investigators are using new data collected in this study and monitoring data from regional state and federal programs in a coupled hydrodynamic-biogeochemical model to understand conditions on the WFS. Hindcast simulations and modeling experiments are assessing how large inputs of nutrients and organic matter affect phytoplankton, oxygen conditions, and carbon chemistry. Modeling experiments are exploring how storms of varying wind and precipitation intensity affect the WFS and estuaries, identifying the tipping point at which the WFS switches from episodic to persistent hypoxia.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.