Ages of River Plumes and Freshened Coastal Waters Using Ra-224 and Ra-223

9314587摩尔这个研究项目将使用寿命较短的镭同位素来确定淡水的年龄，因为这些海水从沿海地带移动并混合到公海中。这些技术应该使海洋科学家能够在几天到几周的时间尺度上追踪沿海水域的移动和混合。这些研究将提供关于沿海海洋和海洋以及海洋内部之间耦合的重要信息。当与其他研究相结合时，这些技术将使海洋学家能够评估将新鲜的沿海水域与其他表层海洋分开的密度梯度上的物质通量。这项工作是基于一种新的短寿命Ra同位素测量技术，224Ra(半衰期=3.6天)和223Ra(半衰期=11.4天)。最初，大部分工作将致力于技术开发和验证。然后，实地研究将确定(1)密西西比河新鲜的河流羽流侵入墨西哥湾的速度，以及(2)从近海岸水域穿过南大西洋海湾内陆架和中陆架地区的混合速度。

9314587 MOORE This research project will use short lived radium isotopes to determine the ages of freshened waters as these waters move and mix from the coastal zone into the open ocean. These techniques should enable marine scientists to tract the movement and mixing of coastal waters on time scales of a few days to several weeks. These studies will provide important information on the coupling between the coastal ocean and the ocean and the ocean interior. When combined with other studies, these techniques will enable oceanographers to assess fluxes of materials across the density gradient separating freshened coastal waters from the rest of the surface ocean. This work is based on a new measurement technique for short lived Ra isotopes, 224 Ra (half life = 3.6 days) and 223 Ra (half life = 11.4 days). Most of the effort will be devoted to technique development and verification initially. Field Studies will then determine (1) the rate at which the freshened river plume of the Mississippi River intrudes into the Gulf of Mexico and (2) the rate of mixing from near coastal waters across the inner and mid shelf region of the south Atlantic Bight.