Preprints
https://doi.org/10.2139/ssrn.4737919
https://doi.org/10.2139/ssrn.4737919
25 Mar 2024
 | 25 Mar 2024
Status: this preprint is open for discussion.

Measurements of Frazil Ice Flocs in Rivers

Chuankang Pei, Jiaqi Yang, Yuntong She, and Mark Loewen

Abstract. Frazil floc sizes and concentrations have been investigated in a small number of laboratory studies but no detailed field measurements have been reported previously. In this study, a submersible camera system was deployed a total of eleven times during the principal and residual supercooling phases in the North Saskatchewan, Peace, and Kananaskis Rivers to capture time-series images of frazil ice particles and flocs. Images were processed to accurately identify flocs and to calculate their sizes and concentrations. Key hydraulic and meteorological measurements were collected and air-water heat fluxes were estimated to investigate their influence on floc properties. A lognormal distribution was found to be a good fit for the floc size distribution. The mean floc size ranged from 1.19 to 5.64 mm and the overall mean floc size was 3.80 mm. The mean floc size decreased linearly as the local Reynolds number increased. The average floc number concentration ranged from 1.80 × 10−4 to 1.15 × 10−1 cm−3. The average floc volumetric concentration ranged from 2.05 × 10−7 to 4.56 × 10−3 and was found to correlate strongly with the relative depth of the measurements. No significant correlations were found between the air-water heat flux and floc properties. Time series analysis showed that during the principal supercooling phase, floc number concentration and mean size increased significantly just prior to peak supercooling and reached a maximum near the end of principal supercooling. During the residual supercooling phase, the mean floc size did not typically vary significantly even 2.5 hours after the residual phase ended and the water temperature increased above zero degrees.

Chuankang Pei, Jiaqi Yang, Yuntong She, and Mark Loewen

Status: open (until 10 May 2024)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on egusphere-2024-619', Steve Daly, 10 Apr 2024 reply
Chuankang Pei, Jiaqi Yang, Yuntong She, and Mark Loewen
Chuankang Pei, Jiaqi Yang, Yuntong She, and Mark Loewen

Viewed

Since the preprint corresponding to this journal article was posted outside of Copernicus Publications, the preprint-related metrics are limited to HTML views.

Total article views: 71 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
71 0 0 71 0 0
  • HTML: 71
  • PDF: 0
  • XML: 0
  • Total: 71
  • BibTeX: 0
  • EndNote: 0
Views and downloads (calculated since 25 Mar 2024)
Cumulative views and downloads (calculated since 25 Mar 2024)

Viewed (geographical distribution)

Since the preprint corresponding to this journal article was posted outside of Copernicus Publications, the preprint-related metrics are limited to HTML views.

Total article views: 71 (including HTML, PDF, and XML) Thereof 71 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 13 Apr 2024
Download
Short summary
Frazil flocs are aggregates of frazil ice particles formed in supercooled water, as they grow they rise to the river surface contributing to ice cover formation. We measured the properties of frazil flocs in rivers for the first time using an underwater imaging. We found the floc size distributions follow a lognormal distribution, and that mean floc size decreases linearly as the local Reynolds number increases. Floc volume concentration has a power law correlation with the relative depth.