11:30 AM - 11:45 AM
[ACG46-04] Development of IMU-based wave buoy for wave observations in the high latitudes
Keywords:waves, high latitudes , sensor
Driven by technological advances in low-cost electronics and prototyping, an intensive deployment of ocean sensing devices is becoming more feasible. Such observation is particularly effective in studying phenomena with relatively large spatial variations such as waves under typhoons and waves under sea ice. With these in mind, we have developed an inexpensive small drifting wave buoy FZ on our own. The buoy hull is compact in size as the diameter is only 20 cm and is produced by using a 3D printer with special care for possible seawater intrusion. A firmware written in CircuitPython is also developed to control a microcontroller to estimate the frequency wave spectra based on the vertical acceleration from the Inertial Measurement Unit (IMU). The measurement results of the power spectrum, the geographical location from the GPS sensor, and several other information on the sensor device are transmitted via Iridium SBD.
Twelve FZ wave buoys were deployed as wave buoy array from R/V Mirai in the Beaufort Sea in the western Arctic Ocean in September 2022. Since the research vessel is a non-ice breaker, the deployments were limited to the ice-free areas although several buoys were deployed near the ice edge. Three commercial drifting wave buoy Spotter were also deployed and used for the validation of FZ wave buoy. It has been found that approximately for the first two weeks the developed wave buoy showed a good agreement in terms of the significant wave height and mean wave period. The agreement deteriorated after two weeks for some reason. In the middle of October, the data transmission became largely intermittent. The cause is conjectured as the icing of seawater on the surface of the drifting wave buoy, which would disturb the data transmission. The seawater temperature measured by the Spotter wave buoys was indeed close to the freezing point when the interruption was observed. The hull size or shape is probably important for the data transmission because almost no interruption in the data transmission was found for Spotter wave buoys whose size is two times larger than the developed wave buoy.
Twelve FZ wave buoys were deployed as wave buoy array from R/V Mirai in the Beaufort Sea in the western Arctic Ocean in September 2022. Since the research vessel is a non-ice breaker, the deployments were limited to the ice-free areas although several buoys were deployed near the ice edge. Three commercial drifting wave buoy Spotter were also deployed and used for the validation of FZ wave buoy. It has been found that approximately for the first two weeks the developed wave buoy showed a good agreement in terms of the significant wave height and mean wave period. The agreement deteriorated after two weeks for some reason. In the middle of October, the data transmission became largely intermittent. The cause is conjectured as the icing of seawater on the surface of the drifting wave buoy, which would disturb the data transmission. The seawater temperature measured by the Spotter wave buoys was indeed close to the freezing point when the interruption was observed. The hull size or shape is probably important for the data transmission because almost no interruption in the data transmission was found for Spotter wave buoys whose size is two times larger than the developed wave buoy.