Improving inter-volume extractions from research radar measurements in complex flow fields

Date

2022-08

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Abstract

The wind can be a destructible force, severely damaging structures, and resulting in significant expense and even loss of life. Obtaining a better understanding of the structure of wind near the surface where the built environment exists can help prevent loss of life and property, as the information can feed engineering-based design and modeling efforts. A crucial step in this process is understanding the smaller scales of motion in different types of weather events, especially those that pose a higher risk of damage occurrence such as thunderstorms.
Historically, this work has been completed by engineers using wind measurements collected from anemometers, but recent research has shown promise in extracting smaller scales of motion from the lower atmosphere using research radar measurements and resulting dual-Doppler (DD) wind fields. The implementation of advection correction and space-to-time conversion methodologies can allow researchers to obtain a better representation of engineering-relevant wind features within the radar-derived wind fields by more appropriately aligning successive radar scans on varying elevation planes in time and space. Extractions can then be conducted from these corrected radar wind fields to produce high temporal resolution time histories across the radar analysis domain. However, the application of these methodologies for complex wind flows, including thunderstorm outflows, is not straight forward.
This study worked to develop new methods to estimate the advection between DD volumes and perform space-to-time conversion to better characterize complex wind flows while preserving the smaller scales of motion desirable to the engineering community. A single case collected by the Texas Tech University Ka band mobile Doppler radars at Reese Technology Center (RTC) during the passage of a thunderstorm was used to test the new methodologies. Validation of the resulting DD second-by-second projections was performed using the 200 m meteorological tower at the RTC field site. Extracted time histories of wind speeds and directions from the two measurement sources were compared, as well as time histories of the engineering relevant parameters longitudinal integral scales, gust factors, and turbulence intensities. Power spectral densities were also calculated for both measurement sources. The results of this study suggest that the new methodologies developed allow for a proper characterization of small-scale features within a complex wind flow.


Embargo status: Restricted until 09/2027. To request the author grant access, click on the PDF link to the left.

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Keywords

Radar, Advection, Projection, Interpolate

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