CAREER: Modeling 19th century estuaries to address 21st century problems

解决21世纪的问题，如沿海洪水，海平面上升和盐度入侵，需要了解潮汐和水位的长期趋势和空间格局。 需要对历史条件进行历史观察和回顾性建模，以充分评估和解释长期趋势的原因。本研究将调查长期动态的潮汐和运输在哥伦比亚河口使用可验证的数据，阐明系统的敏感性。著名的，理想化的见解潮汐动力学和标量传输将在一个复杂的环境中进行测试，以测试如何改变当地地形，湿地面积和深度产生的物理变化。所提出的动力学问题可能对全球河口的过去发展和未来轨迹产生影响。该项目将培养一名研究生，并参与高中教师和代表性不足的学生。这项研究利用了正在进行的努力，以收集19世纪世纪的数据和最近开发的数值模型的历史哥伦比亚河口。通过开创校准历史模型的新方法，并通过历史/现代模型比较评估时空趋势，该项目将为其他强烈变化的河口的类似未来研究奠定基础。利用1854年以来的水温时间序列，通过模拟历史水温，将开辟新的天地。由于水温，如盐度，混合沿着河流/海洋连续，它将被用来校准和验证盐度入侵的历史和现代模型。这种方法避免了历史盐度数据的缺乏，增加了模型的保真度，并允许基于过程的研究，以确定改变水位，栖息地淹没，斜压环流和运输的历史因素。主要假设是：（a）自19世纪以来，直接的人为改变，而不是气候引起的河流流量或海平面的变化，主导了河口功能的变化;（B）过去水温和盐度的变化比今天大得多，但流量和河道深度的变化增加了盐度的侵入;以及（c）潮汐河流中潮汐传播的变化将反映在改变的洪水波传播中：洪水波将比过去移动得更快，并且分散得更少。

Addressing 21st century problems such as coastal flooding, sea-level rise, and salinity intrusion requires understanding both long-term trends and spatial patterns in tides and water level. Historical observations and retrospective modeling of historical conditions are needed to fully evaluate and interpret the cause of long term trends. This study will investigate the long-term dynamics of tides and transport in the Columbia River Estuary using verifiable data to elucidate system sensitivities. Well-known, idealized insights into tidal dynamics and scalar transport will be tested in a complex environment, to test how altered local topography, wetland area, and depth have produced physical changes. The dynamical questions raised may have implications for the past development and future trajectory of estuaries globally. The project will train a graduate student and engage High School teachers and underrepresented students.This study leverages ongoing efforts to digitize 19th century data and a recently developed numerical model of the historic Columbia River Estuary. By pioneering new ways of calibrating historical models and evaluating spatio-temporal trends via historical/modern model comparison, this project will lay the groundwork for similar, future research in other strongly-altered estuaries. Using time series of water temperature back to 1854, new ground will be broken by simulating historical water temperatures. Because water temperature, like salinity, is mixed along the river/ocean continuum, it will be used to calibrate and verify salinity intrusion in both historical and modern models. This approach circumvents the lack of historical salinity data, increases model fidelity, and allows for process-based studies to determine the historical factors which have altered water levels, habitat inundation, baroclinic circulation, and transport. The primary hypotheses are: (a) Direct anthropogenic alterations, rather than climate induced changes to river flow or sea level, have dominated changes to estuary functioning since the 19th century; (b) water temperature and salinity variability was much larger in the past than today but changes in flow and channel depth have increased salinity intrusion; and (c) changes in tide propagation in the tidal river will be reflected in altered flood wave propagation: flood waves will move faster, and disperse less, than in the past.