Radar Doppler spectra recording at the ARM sites. An insight to cloud microphysics and turbulence

The U.S. Department of Energy’s Atmospheric Radiation Measurement (ARM) Program operates several stationary and mobile aerosol and radiation measurement sites in climatologically significant regimes. At the ARM sites, millimeter wavelength profiling Doppler radars (operating at 35and 94-GHz) provide continuous high-resolution (2 sec, 45 m) 256-point FFT Doppler spectra observations of clouds and precipitation. The collection of the Doppler spectra offers new opportunities for the retrieval of microphysics and turbulence in clouds and precipitation. The retrieval techniques are based on the comparison of the detail Doppler spectra, the use of non-Rayleigh features, the presence of multi-modalities and the use of the high-resolution Doppler moments. We will present examples of cloud observations that illustrate interesting microphysical and dynamical features and investigate the coupling between microphysics and turbulence at small-scales.