Using Dual-Polarization Radar Information to Investigate Clear-Air Atmospheric Phenomena
Open Access
- Author:
- Banghoff, John
- Graduate Program:
- Meteorology
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- February 01, 2019
- Committee Members:
- David Jonathan Stensrud, Thesis Advisor/Co-Advisor
Matthew Robert Kumjian, Thesis Advisor/Co-Advisor
George Spencer Young, Committee Member - Keywords:
- Radar
Meteorology
Boundary Layer
Remote Sensing
Dual-Polarization Radar
Horizontal Convective Rolls
Cellular Convection
Clear-Air - Abstract:
- Dual-polarization radar provides a wealth of new information about the type, size, and orientation of scatterers in the atmosphere. This radar information has been interrogated for its applications to hazardous weather, but a wealth of clear-air radar data exists that is signi cantly underutilized. The ability of National Weather Service WSR-88D radars to detect insects and other biota within the convective boundary layer (CBL) facilitates estimation of boundary layer depth and characterization of horizontal convective rolls (HCRs). Bragg scatter signatures in dual-polarization radar observations, which are de ned by low differential reflectivity (ZDR) values, are used as a proxy for CBL depth in 2014 over Central Oklahoma using data from the Twin Lakes (KTLX) WSR-88D. The 243 ZDR Bragg scatter and upper air sounding CBL depth estimates collected during this year have a correlation of 0.90 and a RMSE of 254 m. Additionally, a 10-year climatology of HCRs in Central Oklahoma indicates that HCRs occur on 75% of days during all months of the warm-season (April-September). HCRs typically form in the mid-morning and may persist throughout the day, transition to cellular convection, or develop from cellular convection before dissipating around sunset. These results should facilitate future studies on convection initiation, HCR formation mechanisms, and model parameterization. The methods used to estimate CBL depth and identify and characterize HCRs are potentially applicable across a variety of geographic locations and seasons, and demonstrate the usefulness of clear-air radar data.