In Situ Variability of Large Aggregates over a Fluid Mud Bed: Shear Effects, Settling Velocities and Response to Storms

威尔斯博士之前的研究表明，有机结合的矿物颗粒聚集体在北卡罗莱纳海岸的河口水中相对普遍。这些聚集体（500微米）是海洋生物的食物来源，影响化学分布，并可能造成浅水垂直质量通量的很大一部分。很少有工人能够观察到或恢复这种“海洋雪”。Wells博士和他的合作者luetich博士将利用他们之前获得的NSF奖所开发的技术，分析这些骨料的原位特征。在两年内，每3个月将重新占用观景角湾的横断面；在一年内，每3个月将重新占用垂直剖面；在三次“东北”风暴期间，将保留系泊设施。聚集体的照片，聚集体沉降速度的现场测量，以及在系泊和系绳电缆上记录各种水柱特性的传感器将：1)提供有关了望角湾和巴登湾大聚集体的大小、形状和丰度的详细信息；2)研究水流对大团聚体的影响；3)提供集料沉降速度；4)深入了解大聚集体对风暴事件和其他季节性现象的响应。

Previous work by the Dr. Wells has demonstrated that organically bound aggregates of mineral grains are relatively common to estuarine water along the N. Carolina coast. These aggregates (500 microns) are a food source for marine organisms, affect chemical distributions, and may be responsible for a substantial part of the vertical mass flux in shallow water. Few workers have been able to either observe or recover this "marine snow". Using techniques developed in their previous NSF award, Dr. Wells and his collaborator Dr. Luettich will analyze the in situ characteristics of these aggrregates. Transects of stations across Cape Lookout Bight will be re-occupied every 3 months for 2 years, vertical profiles will be re-occuppied every 3 months for 1 year, and moorings will be left in place for the duration of 3 "northeaster" storms. Photographs of aggregates, in situ measurements of aggregate settling velocities, and sensors recording a variety of water column propoerties on moorings and tethered cables will: 1) yield details about the size, shape and abundance of large aggregates in Cape Lookout Bight and Barden Inlet; 2) investigate the effect of currents on large aggregates; 3) provide settling velocities of aggregates; and 4) provide insight into the reponse of large aggregates to storm events and other seasonal phenomena.