A comparison of vertical velocity variance measurements from wind profiling radars and sonic anemometers

作者：McCaffrey Katherine^*; Bianco Laura; Johnston Paul; Wilczak James M

来源：Atmospheric Measurement Techniques, 2017, 10(3): 999-1015.

DOI：10.5194/amt-10-999-2017

Observations of turbulence in the planetary boundary layer are critical for developing and evaluating boundary layer parameterizations in mesoscale numerical weather prediction models. These observations, however, are expensive and rarely profile the entire boundary layer. Using optimized configurations for 449 and 915MHz wind profiling radars during the eXperimental Planetary boundary layer Instrumentation Assessment (XPIA), improvements have been made to the historical methods of measuring vertical velocity variance through the time series of vertical velocity, as well as the Doppler spectral width. Using six heights of sonic anemometers mounted on a 300m tower, correlations of up to R-2 = 0.74 are seen in measurements of the large-scale variances from the radar time series and R-2 = 0.79 in measurements of small-scale variance from radar spectral widths. The total variance, measured as the sum of the small and large scales, agrees well with sonic anemometers, with R-2 = 0.79. Correlation is higher in daytime convective boundary layers than nighttime stable conditions when turbulence levels are smaller. With the good agreement with the in situ measurements, highly resolved profiles up to 2 km can be accurately observed from the 449MHz radar and 1 km from the 915MHz radar. This optimized configuration will provide unique observations for the verification and improvement to boundary layer parameterizations in mesoscale models.

• 出版日期2017-3-14