Atmospheric Measurement Techniques Discussions www.atmos-meas-tech-discuss.net 1867-8610 3 4 2010 10.5194/amtd-3-3907-2010 http://www.atmos-meas-tech-discuss.net/3/3907/2010/ http://www.atmos-meas-tech-discuss.net/3/3907/2010/amtd-3-3907-2010.html http://www.atmos-meas-tech-discuss.net/3/3907/2010/amtd-3-3907-2010.pdf 3907 3924 2010-08-30 Ceilometer-lidar inter-comparison: backscatter coefficient retrieval and signal-to-noise ratio determination B. Heese birgit.heese@tropos.de H. Flentje D. Althausen A. Ansmann S. Frey Leibniz-Institute for Tropospheric Research, Permoserstr. 15, 04318 Leipzig, Germany German Meteorological Service, Meteorological Observatory Hohenpeissenberg, Germany JENOPTIK, ESW GmbH, Jena, Germany The potential of a new generation of ceilometer instruments for aerosol monitoring has been studied in the Ceilometer-Lidar Inter- Comparison (CLIC) study. The ceilometer is of type CHM15k from Jenoptik, Germany, which uses a solid state laser at the wavelength of 1064 nm and an avalanche photodiode for photon counting detection. The German Meteorological Service is in progress of setting up a ceilometer network for aerosol monitoring in Germany. The intercomparison study was performed to determine whether the ceilometers are capable to deliver quality assured particle backscatter coefficient profiles. For this, the derived ceilometer profiles were compared to simultaneously measured lidar profiles at the same wavelength. The lidar used for this intercomparison was IfTs multi-wavelengths Raman lidar Polly^<i>XT</i>. During the EARLINET lidar intercomparison campaign EARLI 09 in Leipzig, Germany, a new type of the Jenoptik ceilometer, the CHM15k-X, took part. This new ceilometer has a new optical setup resulting in a complete overlap at 150 m. The derived particle backscatter profiles were compared to profiles derived from Polly^<i>XT</i>s measurements, too. The elastic daytime particle backscatter profiles as well as the less noisy night-time Raman particle backscatter profiles compare well with the ceilometers profiles in atmospheric structures like aerosol layers or the boundary layer top height. The calibration of the ceilometer profiles by an independent measurement of the aerosol optical depth (AOD) by a sun photometer is necessary to determine the correct magnitude of the particle backscatter coefficient profiles. A comprehensive signal-to-noise ratio study was carried out to characterize the ceilometers signal performance with increasing altitude. Althausen, D., Engelmann, R., Baars, H., Heese, B., Ansmann, A., Müller, D., and Komppula, M.: Portable Raman Lidar Polly$^XT$ for Automated Profiling of Aerosol Backscatter, Extinction, and Depolarization, J. Atmos. Oceanic Technol., 26, 2366–2378, 2009. Ansmann, A., Riebesell M., and Weitkamp C.: Measurement of atmospheric aerosol extinction profiles with a Raman lidar, Opt. Lett., 15, 746–748, 1990. Flentje, H., Heese, B., Reichardt, J., and Thomas, W.: Aerosol profiling using the ceilometer network of the German Meteorological Service, Atmos. Meas. Tech. Discuss., 3, 3643–3673, doi:10.5194/amtd-3-3643-2010, 2010. Frey, S., Poenitz K., Teschke G., and Wille H.: Detection of aerosol layers with ceilometers and the recognition of the mixed layer depth, presented at the International Symposium for the Advancement of Boundary Layer Remote Sensing (ISARS), 2010. Fernald, F. G.: Analysis of atmospheric lidar observations: some comments, Appl. Optics, 23, 652–653, 1984. Klett, J. D.: Stable analytical inversion solution for processing lidar returns, Appl. Optics, 20, 211–220, 1981. Markovicz, K. M., Flatau, P. J., Kardas, A. E., Remiszewskaj, J., Stelmaszcyk, K., and Wöste, L.: Ceilometer Retrieval of the Boundary Layer Vertical Aerosol Extinction Structure, J. Atmos. Oceanic Technol., 25, 928–944, 2007. Martucci, G., Milroy, C., and O' Dowd, C D.: Detection of Cloud-Base Height Using Jenoptik CHM15K and Vaisala CL31 Ceilometers, J. Atmos. Oceanic Technol., 27, 305­-318, 2010. McKendry, I. G., van der Kampa, D. Strawbridge, K. B., Christen, A., and Crawford, B.: Simultaneous observations of boundary-layer aerosol layers with CL31 ceilometer and 1064/532~nm lidar, Atmos. Env., 43, 5847-5852, 2009. Müller, D., Ansmann, A., Mattis, I., Tesche, M., Wandinger, U., Althausen, D., and Pisani, G.: Aerosol-type-dependent lidar ratios observed with Raman lidar, J. Geophys. Res., 112, D16202, doi:10.1029/2006JD008292, 2007. \clearpage Sundström, A.-M., Nousiainen, T., and Petäjä, T.: On the Quantitative Low-Level Aerosol Measurements Using Ceilometer-Type Lidar, J. Atmos. Oceanic Technol., 26, 2340–2352, 2000. Papparlardo, G., Freudenthaler, V., Mattis, I., et al.: Dispersion and evolution of the Eyjafjallajökull ash plume over Europe: vertically resolved measurements with the European LIDAR network EARLINET, EGU General Assembly, Vienna, 3–7~May~2010.