2018 Hurricane Season: RAPID: Associated Priming of Carbon in the Albemarle-Pamlico Estuarine System (APES), the Mid-Atlantic Bight and Gulf Stream

2018年初秋，两场大西洋飓风（佛罗伦萨和迈克尔）在北卡罗来纳州带来了大量降雨。受这些风暴影响的Albemarle-Pamlico河口系统（APES）是美国第二大河口，接收来自北卡罗来纳州沿海平原地区的淡水，其向海一侧以外滩群岛（OBX）为界。APES和大西洋之间的水和悬浮物交换通过三个入口（俄勒冈州、哈特拉斯和奥克拉科克入口）进行。这项拟议的研究探讨了一个总体假设，即2018年飓风季节的极端降水将陆源有机物质和微生物冲入APES，这些物质将通过OBX入口出口到北大西洋，并影响沿海海洋生态系统。该项目将资助一名研究生和两名本科生。调查人员将通过海岸研究所的“声音科学”系列演示文稿，向OBX沿海社区介绍这项研究的摘要和2018年飓风季节的影响概要。研究人员提出了两个研究问题来解决他们的假设：1）来自佛罗伦萨和迈克尔的陆源溶解有机物和微生物的脉冲是否会将区域墨西哥湾流从净汇改变为大气中二氧化碳的净源，以及2）这种升高的有机物质和营养物质是否会沉积到入口向海的海底，促进厌氧和发酵过程，导致邻近墨西哥湾流的表层沃茨藻类大量繁殖？由于海洋溶解有机物是不同化合物的高度复杂和多分散的混合物，风暴造成的启动和生物降解，即使是在初级水平，也可能对沿海碳循环产生重大影响。北美区域碳预算存在很大的不确定性。据预测，在全球范围内，强降雨事件（定义为每日降雨事件的0.3%以上）和4级和5级大西洋飓风的频率将在热带地区增加。此外，大量陆源有机物、营养物质和微生物的侵蚀和夹带，共同造成区域碳收支在空间和时间上的广泛不确定性。这项研究将提供数据，减少这些不确定性在大西洋沿岸，在一个地区毗邻墨西哥湾流。这个奖项反映了NSF的法定使命，并已被认为是值得的支持，通过评估使用基金会的智力价值和更广泛的影响审查标准。

In the early fall of 2018, two Atlantic hurricanes (Florence and Michael) deposited substantial amounts of rainfall in North Carolina. The Albemarle-Pamlico Estuarine System (APES), which was impacted by these storms, is the second largest estuary in the United States, receiving freshwater from the Coastal Plain region of North Carolina and bounded on its seaward side by the Outer Banks (OBX). The exchange of water and suspended materials between the APES and the Atlantic Ocean occurs through three inlets (Oregon, Hatteras, and Ocracoke Inlets). This proposed research explores the overarching hypothesis that extreme precipitation from the 2018 Hurricane Season flushed land-derived organic material and microbes into the APES and that material will be exported into the North Atlantic through the OBX inlets, and impact coastal ocean ecosystems. The project will support a graduate student and two undergraduates. The investigators will present a summary of this research and synopsis of the impacts from the 2018 Hurricane Season to the OBX coastal community through the "Science on the Sound" presentation series at the Coastal Studies Institute. The investigators propose two research questions to address their hypothesis: 1) will the pulse of the terrigenous dissolved organic matter and microbes from Florence and Michael change the regional Gulf Stream from a net sink to a net source of carbon dioxide to the atmosphere, and 2) will deposition of this elevated organic material and nutrients to the seabed seaward of the inlets, promote anaerobic and fermentation processes that will lead to algal blooms in surface waters adjacent to the Gulf Stream? Because marine dissolved organic matter is a highly complex and polydisperse mixture of different compounds, its priming and biodegradation resulting from the storms, even at rudimentary levels, may significantly affect coastal carbon cycling. Large uncertainties exist in the regional carbon budgets of North America. Intense rain events (as defined by the upper 0.3% of daily rain events) and Category 4 and 5 Atlantic hurricanes are predicted to increase in frequency in extratropical regions, globally. Also, the erosion and entrainment of the substantial amounts of land-derived organic matter, nutrients, and microbes, collectively contribute to broad spatial and temporal uncertainties in regional carbon budgets. This study will provide data reducing these uncertainties in the Atlantic seaboard, in an area adjacent to the Gulf Stream.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.