Three‐dimensional dense distributed temperature sensing for measuring layered thermohaline systems

Abstract

AbstractDistributed temperature sensing has proven a useful technique for geoscientists to obtain spatially distributed temperature data. When studies require high‐resolution temperature data in three spatial dimensions, current practices to enhance the spatial resolution do not suffice. For example, double‐diffusive phenomena induce sharp and small‐scale temperature patterns in water bodies subject to thermohaline gradients. This article presents a novel approach for a 3‐D dense distributed temperature sensing setup, the design of which can be customized to the required spatial resolution in each dimension. Temperature is measured along fiber‐optic cables that can be arranged as needed. In this case, we built a dense cage of very thin (1.6 mm) cables to ensure that interference with flow patterns was minimal. Application in water bodies with double‐diffusion‐induced sharp temperature gradients shows that the setup is well able to capture small‐scale temperature patterns and even detects small unsuspected seeps and potential salt‐fingers. However, the potential effect of the setup on the flow patterns requires further study.