In-Situ Detection for Ocean Internal Solitary Waves Based on a Miniaturized Microfiber-Optic Salinity Sensor

Abstract

Microfiber sensor was regarded as a promising salinity measurement approach in marine surveying. However, the stability and adaptability of microfiber sensors to the complicate and variable moving seawater environment are usually poor. In this paper, a well-encapsulated miniaturized microfiber-optic sensor is proposed for salinity measurement in dynamic seawater environment. The sensor shows a fast response time of about 80 ms, good repeatability, good stability in water current, and good long-term working ability, which indicates that the sensor is a promising device in marine detection. After calibrated, the sensor is applied to the in-situ detection for the actual internal solitary wave (ISW), including the vertical salinity profile and the salinity measurement during the ISW propagation process. Results show that the propagation time of ISW captured by the microfiber sensor and the amplitude of ISW measured by the sensor are both in good agreement with those captured by CCD camera. This paper shows a microfiber salinity sensor with good performance, which will offer useful reference for promoting the practicality of microfiber sensors.