Improved observations of turbulence dissipation rates from wind profiling radars

Katherine McCaffrey, Laura Bianco, James M. Wilczak
2017 Atmospheric Measurement Techniques  
<p><strong>Abstract.</strong> Observations of turbulence dissipation rates in the planetary boundary layer are crucial for validation of parameterizations in numerical weather prediction models. However, because dissipation rates are difficult to obtain, they are infrequently measured through the depth of the boundary layer. For this reason, demonstrating the ability of commonly used wind profiling radars (WPRs) to estimate this quantity would be greatly beneficial. During the XPIA field
more » ... e XPIA field campaign at the Boulder Atmospheric Observatory, two WPRs operated in an optimized configuration, using high spectral resolution for increased accuracy of Doppler spectral width, specifically chosen to estimate turbulence from a vertically pointing beam. Multiple post-processing techniques, including different numbers of spectral averages and peak processing algorithms for calculating spectral moments, were evaluated to determine the most accurate procedures for estimating turbulence dissipation rates using the information contained in the Doppler spectral width, using sonic anemometers mounted on a 300<span class="thinspace"></span>m tower for validation. The optimal settings were determined, producing a low bias, which was later corrected. Resulting estimations of turbulence dissipation rates correlated well (<i>R</i><sup>2</sup> = 0. 54 and 0. 41) with the sonic anemometers, and profiles up to 2<span class="thinspace"></span>km from the 449<span class="thinspace"></span>MHz WPR and 1<span class="thinspace"></span>km from the 915<span class="thinspace"></span>MHz WPR were observed.</p>
doi:10.5194/amt-10-2595-2017 fatcat:skd4isyjp5gjbkhhcz7bpynk5y