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Multi-variable turbulence characteristics of the daytime atmospheric boundary layer over an arid region using measurements from a 200-m tall tower
  • Matthew Hamel,
  • Sandip Pal,
  • Brian Hirth
Matthew Hamel
Wind Science and Engineering, National Wind Institute, Texas Tech University

Corresponding Author:[email protected]

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Sandip Pal
Department of Geosciences, Atmospheric Science Division, Texas Tech University
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Brian Hirth
National Wind Institute, Texas Tech University
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Abstract

Turbulence parameterizations (TP) in numerical weather prediction models remains one of the challenging tasks as we lack a comprehensive understanding on the turbulence processes under myriad weather conditions. One way to make improvements to these TPs is through obtaining empirical evidence of turbulence structures via exploring multi-parameter turbulence analyses. To the best of our knowledge, we reported here the first multi-parameter vertical profiles of turbulence characteristics based on the analyses of higher-order moments of five key thermodynamic variables in the lower part of the atmospheric boundary layer (ABL) over an arid region. Observational studies reporting turbulence features in the ABL over arid regions remain underexplored although drylands are home to more than 38% of the world’s population. Due to lack of adequate soil moisture, two of the key features of land-atmosphere feedback over an arid region are strong sensible-heat fluxes and intense turbulent-mixing. We used high-resolution (50-Hz) measurements of 3-d wind components, moisture, and temperature obtained at 10 vertical levels on a 200-m Tall Tower at Reese Technology Center in Lubbock located in Texas Panhandle in the US to explore turbulence characteristics under synoptically benign weather conditions. To demonstrate the method, we choose a case study (18 July 2020) where we used daytime measurements obtained on the tower from 17:00-00:00 UTC (12:00-19:00 LT). We found evidence that there is an altitude dependence on the location of the peak values of the variance and skewness of the vertical, zonal, and meridional velocity, potential temperature, and specific humidity.