Collaborative Research: Multiple Stressors in the Estuarine Environment: What drives changes in the Carbon Dioxide system?

合作研究：河口环境中的多重压力源：是什么推动了二氧化碳系统的变化？

• 批准号: 1536996
• 负责人: Raymond Najjar
• 金额: $ 18万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-10-01 至 2020-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1536996&HistoricalAwards=false
• 关键词: Collaborative; Research; Multiple; Stressors; Estuarine

Understanding the vulnerability of estuarine ecosystems to anthropogenic impacts requires a quantitative assessment of the dynamic drivers of change to the estuarine carbonate system. Estuaries are currently experiencing multiple environmental stressors that have significant impacts on their carbonate chemistry, making this assessment a major challenge. Although the effects of changes in nutrient run-off (i.e. eutrophication and hypoxia) have been long-studied in many estuaries, much less attention has been given to the impacts of global change on these systems. In this study, a team of field scientists and modelers will attempt to distinguish natural interannual variability in a major US estuary from the impacts of local anthropogenic changes (e.g., nutrient inputs, changing freshwater end member characteristics) and global change (increases in atmospheric temperature, atmospheric carbon dioxide, and sea level), by using numerical models calibrated with CO2-system observations at appropriate spatial and temporal scales. If successful, this will be the first study to quantitatively distinguish between local and global anthropogenic impacts on the CO2 system in an estuary. The results are expected to have important implications for management of Chesapeake Bay because the impact of local anthropogenic stressors on the system, once isolated, may be mitigated by appropriate environmental policy implemented at the regional scale. Two of the PIs have a strong history of proven relationships with Chesapeake Bay managers and policy makers, which will insure direct infusion of these scientific results into ongoing management decisions.In this project researchers will study the diurnal, seasonal, and interannual variability of the CO2 system in the Chesapeake Bay, a non-pristine estuary, using a combination of conventional shipboard sampling (of dissolved inorganic carbon, and alkalinity) and new high-frequency autonomous instrumentation (for observations of pH and CO2 partial pressure) to assess the impact of extreme events, like tropical storms and nor?easters on carbonate chemistry. These high-quality observations will afford a rigorous assessment of the uncertainty associated with a 30-year water-quality monitoring time series of pH and alkalinity. The team will use an estuarine-carbon-biogeochemical model evaluated and calibrated with the new and long-term observations. Sensitivity experiments will be applied to disentangle multiple impacts on the CO2 system in the estuary over the last 30 years, including increased atmospheric temperature and CO2, sea-level rise, eutrophication due to increases in nutrient run-off, and changing carbonate characteristics of riverine end-members.

了解河口生态系统对人为影响的脆弱性需要对河口碳酸盐系统变化的动态驱动因素进行定量评估。河口目前正经历多种环境压力因素，对其碳酸盐化学产生重大影响，使这项评估成为一项重大挑战。尽管许多河口长期以来一直在研究营养物径流变化（即富营养化和缺氧）的影响，但人们对全球变化对这些系统的影响的关注却少得多。在这项研究中，由实地科学家和建模师组成的团队将尝试将美国主要河口的自然年际变化与当地人为变化（例如营养物质输入、淡水端成员特征的变化）和全球变化（大气温度升高）的影响区分开来。 、大气二氧化碳和海平面），通过使用在适当的空间和时间尺度上用二氧化碳系统观测值校准的数值模型。 如果成功，这将是第一项定量区分当地和全球人为对河口二氧化碳系统影响的研究。 预计结果将对切萨皮克湾的管理产生重要影响，因为当地人为压力源对系统的影响一旦被隔离，可以通过在区域范围内实施适当的环境政策来减轻。其中两位 PI 与切萨皮克湾管理者和政策制定者有着良好的关系历史，这将确保这些科学成果直接融入到持续的管理决策中。在这个项目中，研究人员将研究二氧化碳的昼夜、季节和年际变化。切萨皮克湾（一个非原始河口）的系统，结合使用传统的船上采样（溶解的无机碳和碱度）和新型高频自主仪器（用于观测 pH 值和碱度） CO2 分压）来评估极端事件（如热带风暴和东北风暴）对碳酸盐化学的影响。这些高质量的观测结果将对 30 年 pH 值和碱度水质监测时间序列相关的不确定性进行严格评估。该团队将使用河口碳生物地球化学模型，并根据新的长期观测结果进行评估和校准。将应用敏感性实验来理清过去30年对河口二氧化碳系统的多重影响，包括大气温度和二氧化碳的增加、海平面上升、营养物径流增加造成的富营养化以及河流碳酸盐特征的变化最终成员。