Since 2006 different remote monitoring methods for mixing layer height have been operated in Augsburg. One method is based on eye-safe commercial mini-lidar systems (ceilometers). The optical backscatter intensities recorded with these ceilometers provide information about the range-dependent aerosol concentration; gradient minima within this profile mark the tops of mixed layers. A special software for these ceilometers provides routine retrievals of lower atmosphere layering. A second method, based on SODAR (Sound Detection and Ranging) observations, detects the height of a turbulent layer characterized by high acoustic backscatter intensities due to thermal fluctuations and a high variance of the vertical velocity component. This information is extended by measurements with a RASS (Radio-Acoustic Sounding System) which provide the vertical temperature profile from the detection of acoustic signal propagation and thus temperature inversions which mark atmospheric layers. These SODAR and RASS data are the input to a software-based determination of mixing layer heights developed with MATLAB. A comparison of results of the three remote sensing methods during simultaneous measurements was performed. The information content of the ceilometer data is assessed by comparing it to the results from the other two instruments and near-by radiosonde data.

Date Published: 27 October 2010
PDF: 9 pages
Proc. SPIE 7827, Remote Sensing of Clouds and the Atmosphere XV, 782707 (27 October 2010); doi: 10.1117/12.865108

Published in SPIE Proceedings Vol. 7827:
Remote Sensing of Clouds and the Atmosphere XV
Richard H. Picard; Klaus Schäfer; Adolfo Comeron; Michiel van Weele, Editor(s)