A Facility for Dynamic-Response Studies

0240956施密特研制了一种能够长期维持尖锐温度-盐度界面的大型水箱，并应用于海洋传感器动态响应的测量。电导率和温度传感器的动态响应匹配一直是盐度计算中的一个长期问题，该水箱为解决这一问题提供了一种新的方法。该项目将改进现有的水箱，评估一些可用的CTD.，并为盐度估计提供改进的算法。新的水箱使用4.7米深的双层盐层系统，从下面加热，从上面冷却。这产生了两个对流混合层，它们之间有一个薄的双扩散界面。5-10摄氏度的温度跃升可以在1-2厘米(约103摄氏度/米的垂直温度梯度)上保持约2周。变速降速系统允许测试全尺寸海洋仪器中的电导率和温度传感器的动态响应。声学回声测深仪和光学阴影系统提供对界面和层微结构的非破坏性监控。已经开发了线性和非线性拟合例程来确定温度计响应时间，这是速度的强函数。基于界面上电导率-温度关系的强制线性，发展了一种优化设计滞后校正滤光片的方法，以精确匹配用于计算盐度的温度和电导率传感器。传感器响应特性对于必须在现场进行数据处理和压缩的自主仪器尤其重要，但也有助于开发新的传感器，并确保从传统的绳索下降和拖曳系统获得准确的盐度记录。该项目将对该水箱进行若干改进，评估几个现有的CTD，为计算盐度提出改进的算法，并将该水箱建立为供海洋界使用的动态反应设施。这项工作的更广泛影响部分源于它对改进气候变化研究的海洋观测的迫切社会需求的贡献。此外，动态反应设施将是一个社区范围的资源，用于改善营利性和非营利性部门在盐度观测方面的最新水平。最后，它将继续使用和培训研究生和本科生在其业务。

0240956 SchmittA large tank capable of long-term maintenance of a sharp temperature-salinity interface has been developed and applied to measurements of the dynamical response of oceanographic sensors. Matching the dynamic response of conductivity and temperature sensors has been a long-standing problem in the computation of salinity, and this tank offers a new approach to its solution. This project will improve the existing tank, evaluate a number of available CTDs., and provide improved algorithms for the estimation of salinity. The new tank uses a two-layer salt-stratified system 4.7 m deep that is heated from below and cooled from above. This generates two convectively mixed layers with a thin double-diffusive interface separating them. A temperature jump of 5-10 degrees C can be maintained over 1-2 cm (a vertical temperature gradient of order 103 degrees C/m) for ~2 weeks. A variable speed lowering system allows testing of the dynamic response of conductivity and temperature sensors in full-size oceanographic instruments. An acoustic echo sounder and an optical shadowgraph system provide non-disruptive monitoring of the interface and layer microstructure. Linear and nonlinear fitting routines have been developed to determine thermometer response times that are a strong function of the speed. A method for the optimal design of lag-correction filters, based on an imposed linearity of the conductivity-temperature relationship across the interface, has been developed to accurately match temperature and conductivity sensors for the computation of salinity. Sensor response characterization is especially important for autonomous instruments where data processing and compression must be performed in-situ, but is also helpful in the development of new sensors and in assuring accurate salinity records from traditional wire-lowered and towed systems. This project will implement a number of improvements to the tank, evaluate several existing CTDs, suggest improved algorithms for the computation of salinity and establish the tank as a dynamic response facility for use of the oceanographic community. The broader impacts of this work stems in part from its contributions to the pressing societal need for improved ocean observations for climate change research. Also, the dynamic response facility will be a community-wide resource for improving the state-of-the art in salinity observations for both the profit and non-profit sectors. Finally, it will continue to utilize and train graduate and undergraduate students in its operations.