The May/June 2008 Saharan dust event over Munich: Intensive aerosol parameters from lidar measurements

the aerosol particles as a function of time and height are derived from data of the two Raman depolarization‐lidar systems MULIS and POLIS at Munich and Maisach (Germany), respectively. Measurements include the extensive properties of the particles, backscatter coefficient bp and extinction coefficient ap, and the intensive particle properties, linear depolarization ratio dp and lidar ratio Sp. All quantities are derived at two wavelengths, l = 355 nm and l = 532 nm. The focus of the study is on the intensive properties, for which we found on average dp = 0.30 at 355 nm and dp = 0.34 at 532 nm. The systematic errors were typically larger than the dp‐difference at the two wavelengths. With respect to the lidar ratio, we found Sp = 59 sr for both wavelengths, with an uncertainty range between ±4 sr and ±10 sr. These values are quite similar to the results from the SAMUM campaigns. Thus, our results suggest that the intensive optical properties of Saharan dust do not change significantly if the transport time is less than one week. However, more case studies in the far‐range regime are required to scrutinize this statement. To further refine conclusions with respect to the wavelength dependence of dp a further reduction of the errors is desired.

[1]  E. Goldberg,et al.  Airborne dust collected at Barbados , 1967 .

[2]  Toby N. Carlson,et al.  Vertical and areal distribution of Saharan dust over the western equatorial north Atlantic Ocean , 1972 .

[3]  Toby N. Carlson,et al.  Saharan air outbreaks over the tropical North Atlantic , 1980 .

[4]  F. G. Fernald Analysis of atmospheric lidar observations: some comments. , 1984, Applied optics.

[5]  J. Klett Lidar inversion with variable backscatter/extinction ratios. , 1985, Applied optics.

[6]  Hybrid single-particle Lagrangian integrated trajectories (HY-SPLIT) : model description , 1988 .

[7]  A. Ansmann,et al.  Independent measurement of extinction and backscatter profiles in cirrus clouds by using a combined Raman elastic-backscatter lidar. , 1992, Applied optics.

[8]  A. Lacis,et al.  The influence on climate forcing of mineral aerosols from disturbed soils , 1996, Nature.

[9]  A. Smirnov,et al.  AERONET-a federated instrument network and data archive for aerosol Characterization , 1998 .

[10]  J. Penner,et al.  Aerosols, their Direct and Indirect Effects , 2001 .

[11]  G. Kallos,et al.  A model for prediction of desert dust cycle in the atmosphere , 2001 .

[12]  J. Penner,et al.  Introduction to special section: Outstanding problems in quantifying the radiative impacts of mineral dust , 2001 .

[13]  A. Ansmann,et al.  Dual‐wavelength Raman lidar observations of the extinction‐to‐backscatter ratio of Saharan dust , 2002 .

[14]  J. Bösenberg,et al.  EARLINET: A European Aerosol Research Lidar Network to Establish an Aerosol Climatology , 2003 .

[15]  V. Freudenthaler,et al.  Long-range transport of Saharan dust to northern Europe : The 11-16 October 2001 outbreak observed with EARLINET , 2003 .

[16]  Yoram J. Kaufman,et al.  Intercomparison of satellite retrieved aerosol optical depth over ocean during the period September 1997 to December 2000 , 2004 .

[17]  C. Zender,et al.  Quantifying mineral dust mass budgets:Terminology, constraints, and current estimates , 2004 .

[18]  D. Koch,et al.  Constraining the magnitude of the global dust cycle by minimizing the difference between a model and observations , 2006 .

[19]  Peter J. Minnett,et al.  Measuring Trans-Atlantic aerosol transport from Africa , 2006 .

[20]  L. Mona,et al.  Saharan dust intrusions in the Mediterranean area: Three years of Raman lidar measurements , 2006 .

[21]  D. Winker,et al.  Initial performance assessment of CALIOP , 2007 .

[22]  L. Mona,et al.  Systematic lidar observations of Saharan dust over Europe in the frame of EARLINET (2000-2002) , 2008 .

[23]  G. Gimmestad,et al.  Reexamination of depolarization in lidar measurements. , 2008, Applied optics.

[24]  F. Olmo,et al.  Extreme Saharan dust event over the southern Iberian Peninsula in september 2007: active and passive remote sensing from surface and satellite , 2009 .

[25]  V. Freudenthaler,et al.  Depolarization ratio profiling at several wavelengths in pure Saharan dust during SAMUM 2006 , 2009 .

[26]  Albert Ansmann,et al.  Vertical profiling of Saharan dust with Raman lidars and airborne HSRL in southern Morocco during SAMUM , 2009 .

[27]  J. Heintzenberg The SAMUM-1 experiment over Southern Morocco: overview and introduction , 2009 .

[28]  V. Cachorro,et al.  Synergetic monitoring of Saharan dust plumes and potential impact on surface: a case study of dust transport from Canary Islands to Iberian Peninsula , 2010 .

[29]  V. Freudenthaler,et al.  Characterization of Saharan dust, marine aerosols and mixtures of biomass-burning aerosols and dust by means of multi-wavelength depolarization and Raman lidar measurements during SAMUM 2 , 2011 .

[30]  V. Freudenthaler,et al.  Lidar ratio of Saharan dust over Cape Verde Islands: Assessment and error calculation , 2011 .

[31]  Josef Gasteiger,et al.  Modelling lidar-relevant optical properties of complex mineral dust aerosols , 2011 .

[32]  V. Freudenthaler,et al.  Dual-wavelength linear depolarization ratio of volcanic aerosols: Lidar measurements of the Eyjafjallajökull plume over Maisach, Germany , 2012 .

[33]  V. Freudenthaler,et al.  Characterization of the Eyjafjallajökull ash-plume: Potential of lidar remote sensing , 2012 .