Comparison of Dual Doppler Wind Retrievals with Detailed Wind Profiler Observations within High-Shear Environments during PERiLS

This presentation will summarize preliminary results of comparisons between wind profiles extracted from moderately high-resolution dual Doppler (DD) analyses, and wind profiles derived from 915 MHz radar wind profilers and Doppler lidars. This comparison is motivated by two persuasive reasons: (1)There is a general lack of sources of validation of DD retrievals in previous studies. (2) We have a fundamental interest in documenting and understanding variability of airflow within the highly-sheared boundary layer preceding QLCSs, and combining data from scanning radars and wind profiling systems. This latter goal requires a better understanding of the differences in sampling (and accuracy) of winds retrieved from scanning radar, and profiler systems. Specifically, we are concerned with the accuracy of dual Doppler wind retrievals.

The PERiLS field campaign data provided an excellent opportunity to examine several quantitative comparisons. Here, we utilize primarily the UAH Mobile Atmospheric Profiling Network (MAPNet) profiling systems – Mobile Integrated Profiling System (MIPS), Rapidly Deployable Profiling System (RaDAPS), and Mobile Doppler Lidar and Sounding system (MoDLS) – and scanning radars (COW, DOW7, SR1, NOXP, and MAX) that have available data. During the PERiLS field campaign, networks of scanning radars, radar wind profilers, and lidar profiling systems were configured for each IOP. During IOP3 (24 March 2023), the MIPS location relative to scanning radars was 154°/23 km, 220°/19 km, and 301°/18 km from the COW, NOXP, and SR1 radars, respectively (Fig. 1). Two time periods during light precipitation over the wind profilers are considered during this IOP: (1) tightly-clustered, weak showers around 1930 UTC within low-moderate shear conditions (0-2 km BWD of ~10 m s-1), and a later period of closely-spaced, moderately-intense (40 dBZ) showers around 0030 UTC (Fig. 1), during high-shear conditions (0-2 km BWD of ~25 m s-1). This analysis will address the question: How does the presence of shear potentially degrade the DD wind retrievals, due to slight differences in sampling heights over the domain which produce a mismatch in the wind (vector) profile height being sampled? Around 0045 UTC during same IOP, DD retrievals over the RaDAPS 915 MHz wind profiler, located 154°/34.5 and 82°/33.5 km from the MAX and NOXP radars will be used to assess the impact of longer-range VR measurements (e.g., wider beam sample volume and greater heights in the presence of 25 m s-1 shear) on low-level wind retrieval accuracy. This work is relevant to DD retrievals in highly-sheared flows in both deep convection (QLCS) and the weakly precipitating (or no precipitation) boundary layer to lower atmosphere.