June 13 2024: 12 PM CST: MB BRANCH WEBINAR SERIES: Frazil Ice Measurements Using the Four-Frequency AQUAscat Sonar in Laboratory and Field Environments

This is the seventh and final webinar in the 2023-2024 MB Branch webinar series.

Presenter: Leila Shoorangiz, EIT.

This research describes laboratory experiments conducted to investigate the capability of a multifrequency Aquatec AQUAscat 1000R sonar in detecting and measuring frazil ice particles. A series of laboratory experiments were conducted at the University of Manitoba and the University of Alberta to measure the particle size and concentration of frazil ice particles using four transducers, including 0.3, 0.5, 2 and 4 MHz. Also, the AQUAscat Toolkit software was utilized to post-process the logged data using the sonar instrument. The results indicated that the 2 MHz transducer was the most sensitive to the presence of frazil ice particles, while the 0.3 MHz had the least sensitivity. The device started to detect the frazil ice particles when the maximum supercooling occurred. The concentration was determined to peak at 0.65% and 0.45% in different setups at the University of Manitoba and the University of Alberta, respectively. The outcomes showed that the mean frazil particle size ranged from 100 to 300 µm at the University of Alberta in a supercooling event. In contrast, the findings at the University of Manitoba were unreliable due to the large number of bad cells within the particle size data.

The multifrequency sonar instrument was deployed on the riverbed at Dauphin River for a one-day experiment. It was revealed that the apparatus was able to detect the frazil ice particles but not the frazil flocs and ice rafts. The results showed that the average concentration of frazil ice was 0.0066%.

December 6 th , 2022, Dauphin River, MB

Thank you to Hatch for sponsoring the 2024 CWRA Manitoba Branch webinar series