Collaborative Research: Trace Distributions, Chemical Fluxes, and Distributary Comparisons in the Mixing Zone of the Mississippi River

河口和河流羽流是陆地和海洋之间富有生产力的动态界面，化学通量可以显着改变。然而，一些重要的河口化学通量和过程，其中的物质通量从陆架底部沃茨到半咸水表面沃茨和再生物质的通量在底层沃茨的货架外仍然知之甚少。 来自南密西西比大学、南亚拉巴马大学和南佛罗里达大学的科学家将确定密西西比河流出物中营养物质、微量元素、镭同位素和其他示踪剂的分布，以（1）限制水、营养物质和微量元素通量;（2）比较河口系统中不同分流混合带的化学分布，以了解地文差异如何影响化学通量;（3）研究河流羽流/河口混合带中微量元素的物理化学形态，以了解微量元素的源和汇如何在形态中反映出来;（4）进一步发展和应用镭示踪方法。 实地工作的结果将被纳入质量平衡模型的密西西比河流出系统，提供一个更定量和系统的估计材料通量。至于更广泛的影响，这项研究将进一步我们的运输和河流为主的沿海系统中的营养物质和微量元素的循环的理解。 了解这些元素在沿海和河口系统中的通量将有助于制定管理模型和设想方案，以预测管理政策对沿海地区化学和生物健康的影响。 这项研究将有助于促进与两名新调查人员的新的机构间合作。 南密西西比大学的两名研究生、南亚拉巴马大学的一名研究生以及南佛罗里达大学的一名研究生和两名本科生将作为该项目的一部分得到支助和培训。

Estuaries and river plumes are productive, dynamic interfaces between the land and the ocean where chemical fluxes can be significantly altered. However, some important estuarine chemical fluxes and processes amongst them the flux of material from shelf bottom waters up into brackish surface waters and the flux of regenerated material off-shelf in bottom waters remain poorly understood. Scientists from the University of Southern Mississippi, the University of South Alabama, and the University of South Florida would determine the distributions of nutrients, trace elements, radium isotopes and other tracers in the outflow of the Mississippi River to (1) to constrain water, nutrient and trace element fluxes; (2) to compare chemical distributions in different distributary mixing zones of an estuarine system to see how physiographic differences affect chemical fluxes; (3) to examine physical-chemical speciation of trace elements in a river plume/estuary mixing zone to see how sources and sinks of the trace elements are reflected in the speciation; and (4) to further develop and apply radium tracer methodology to these problems. Results of the field work would be incorporated into mass balance models of the Mississippi River outflow system to provide a more quantitative and systematic estimate of material fluxes. As regards broader impacts, this study would further our understanding of transport and cycling of nutrients and trace elements in river-dominated coastal systems. Understanding the fluxes of these elements in coastal and estuarine systems would allow for the development of management models and scenarios to predict the effect of management policies on the chemical and biological health of the coastal zone. This study would help foster new inter-institutional collaborations with two new investigators. Two graduate students from the University of Southern Mississippi, one graduate student from the University of South Alabama, and one graduate student and two undergraduate students from the University of South Florida would be supported and trained as part of this project.