The SGP and TWP (Manus) Ice Cloud Vertical Velocities data set includes daily observations of high-cloud dynamics at the two ARM sites. The files include variables at three time resolutions: 10 seconds, 20 minutes, and 1 hour. Profiles of radar reflectivity factor, Doppler velocity, retrieved vertical air motion and reflectivity-weighted particle terminal fall velocity are given at the same time resolution. Lower level clouds are removed; however, a multilayer flag is included. In addition to these variables, cloud bases, tops, and thicknesses are included at 20-minute and 1-hour resolution.
Doppler radar velocity measurements allow for observation of ice-cloud dynamics in the presence and absence of gravity waves. The vertical air motion is used to detect gravity waves in persistent high clouds (>2-hour longevity) via wavelet analysis. High clouds are found to be less turbulent when gravity waves are observed. For these long-lived clouds, turbulence is determined via the fast Fourier transform algorithm; turbulent energy fraction and turbulent kinetic energy dissipation rate are included in the files.
A description of the Doppler-velocity decomposition technique used in this data product is given in Kalesse H, P Kollias, 2013, Climatology of High Cloud Dynamics Using Profiling ARM Doppler Radar Observations, Journal of Climate 26, 6340–6359.
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This work was supported by the U.S. Department of Energy’s Office of Science, through the Biological and Environmental Research program as part of the Atmospheric System Research program.