Estimating Visibility during Snowfall Using Radar

  • Author / Creator
    Qian, D. Mary
  • To estimate the visibility during snowfall, we compare hourly visibility (Vis) measurements with radar reflectivity factor (Z) measurements sampled over Edmonton International Airport during snowfall events from October 2010 to April 2011. The (Z, Vis) scatter diagrams showed that increasing Z was correlated with decreasing Vis. For a given Z observation, we found the probability distribution of Vis. The interquartile range with Z ≥ 20 dBZ was smaller than the IQR with Z < 20 dBZ. The scatter was not significantly affected by the temperature profile or the wet bulb potential temperature. Strong wind speed (≥15 knots) along with high reflectivity was associated low Vis (< 2 sm). Radar reflectivity data has valuable information for visibility, yet is not a substitute for human observations.

  • Subjects / Keywords
  • Graduation date
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.
  • Language
  • Institution
    University of Alberta
  • Degree level
  • Department
    • Department of Earth and Atmospheric Sciences
  • Supervisor / co-supervisor and their department(s)
    • Gerhard W. Reuter/Department of Earth and Atmosphere Sciences
  • Examining committee members and their departments
    • Frances Fenrich /Department of Physics
    • John D. Wilson /Department of Earth and Atmosphere Sciences