May 22 - July 28
Comparing Differential Reflectivity Arcs Using Phased Array and Conventional Radar Data
Ethan Steward, Charles M. Kuster, A. Addison Alford, Terry J. Schuur, and Vivek N. Mahale
What is already known:
- The current operational weather radar network (WSR-88Ds) has and continues to provide crucial information for the National Weather Service warning decision process, but the radar system’s lifespan is expected to end around 2040.
- Phased array radars (PARs) are candidates for the future generation of radar, providing increased temporal resolution and/or denser vertical sampling of the atmosphere.
- Single-polarization PAR has been shown to bring operational benefit with the ability to detect and track rapid processes in thunderstorms that the WSR-88D could not.
What this study adds:
- Using data from the Advanced Technology Demonstrator (ATD), dual-polarization PAR data are directly compared to KTLX, an operational WSR-88D, to evaluate the spatiotemporal characteristics of differential reflectivity (ZDR) arcs.
- Analysis reveals that rapidly-evolving polarimetric signatures are better resolved with the ATD due to its improved data quality and enhanced vertical resolution.
- Output from the Supercell Polarimetric Observation Research Kit (SPORK) suggests a potential increase in automatic detection capabilities of ZDR arcs using ATD data.
Abstract:
Single-polarization phased array radar (PAR), which offers access to rapid-update radar data, has been shown to bring operational benefit to warning decision environments. However, dual-polarization PAR ca- pabilities have remained largely unexplored. In this study, an investigation into the potential operational benefits of dual-polarization PAR data is performed using the Advanced Technology Demonstrator (ATD). The ATD’s performance is compared to the National Weather Service radar in Oklahoma City (KTLX). The main dual-polarization signature investigated is the differential reflectivity (ZDR) arc in supercell thunder- storms. Appearance and evolution of ZDR arcs can convey information regarding mesocyclone development and intensification to warning meteorologists. The analysis here focuses on comparing ZDR arcs in ATD and KTLX radar data using both quantitative and qualitative methods. Quantitative analyses will yield explicit differences between the two types of radar, while qualitative analyses help visualize the immediate benefits of dual-polarization PAR data in a warning decision environment. The goal of this study is to explore PAR dual-polarization capabilities in observing the rapidly evolving supercell structures in space and time. It is found that ZDR arcs and their trends are better resolved with the ATD’s improved data quality. Additionally, the ATD detected rapidly-evolving signatures, such as ZDR arc disruptions and descending hail cores, faster and clearer than KTLX.