TY - INPR A1 - Böckmann, Christine A1 - Biele, Jens A1 - Neuber, Roland A1 - Niebsch, Jenny T1 - Retrieval of multimodal aerosol size distribution by inversion of multiwavelength data N2 - The ill-posed problem of aerosol size distribution determination from a small number of backscatter and extinction measurements was solved successfully with a mollifier method which is advantageous since the ill-posed part is performed on exactly given quantities, the points r where n(r) is evaluated may be freely selected. A new twodimensional model for the troposphere is proposed. T3 - NLD Preprints - 38 KW - Multiwavelength LIDAR KW - aerosol size distribution KW - ill-posed problem KW - inversion KW - mollifier method KW - coated and absorbing aerosols Y1 - 1997 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-14360 ER - TY - JOUR A1 - Böckmann, Christine A1 - Biele, Jens A1 - Neuber, Roland A1 - Niebsch, Jenny T1 - Retrieval of Multimodal aerosol size distribution by Inversion of Multiwavelength data Y1 - 1997 SN - 0-8194-2525-7 ER - TY - JOUR A1 - Hoffmann, Anne A1 - Osterloh, Lukas A1 - Stone, Robert A1 - Lampert, Astrid A1 - Ritter, Christoph A1 - Stock, Maria A1 - Tunved, Peter A1 - Hennig, Tabea A1 - Böckmann, Christine A1 - Li, Shao-Meng A1 - Eleftheriadis, Kostas A1 - Maturilli, Marion A1 - Orgis, Thomas A1 - Herber, Andreas A1 - Neuber, Roland A1 - Dethloff, Klaus T1 - Remote sensing and in-situ measurements of tropospheric aerosol, a PAMARCMiP case study JF - Atmospheric environment : air pollution ; emissions, transport and dispersion, transformation, deposition effects, micrometeorology, urban atmosphere, global atmosphere N2 - In this work, a closure experiment for tropospheric aerosol is presented. Aerosol size distributions and single scattering albedo from remote sensing data are compared to those measured in-situ. An aerosol pollution event on 4 April 2009 was observed by ground based and airborne lidar and photometer in and around Ny-Alesund, Spitsbergen, as well as by DMPS, nephelometer and particle soot absorption photometer at the nearby Zeppelin Mountain Research Station. The presented measurements were conducted in an area of 40 x 20 km around Ny-Alesund as part of the 2009 Polar Airborne Measurements and Arctic Regional Climate Model Simulation Project (PAMARCMiP). Aerosol mainly in the accumulation mode was found in the lower troposphere, however, enhanced backscattering was observed up to the tropopause altitude. A comparison of meteorological data available at different locations reveals a stable multi-layer-structure of the lower troposphere. It is followed by the retrieval of optical and microphysical aerosol parameters. Extinction values have been derived using two different methods, and it was found that extinction (especially in the UV) derived from Raman lidar data significantly surpasses the extinction derived from photometer AOD profiles. Airborne lidar data shows volume depolarization values to be less than 2.5% between 500 m and 2.5 km altitude, hence, particles in this range can be assumed to be of spherical shape. In-situ particle number concentrations measured at the Zeppelin Mountain Research Station at 474 m altitude peak at about 0.18 mu m diameter, which was also found for the microphysical inversion calculations performed at 850 m and 1500 m altitude. Number concentrations depend on the assumed extinction values, and slightly decrease with altitude as well as the effective particle diameter. A low imaginary part in the derived refractive index suggests weakly absorbing aerosols, which is confirmed by low black carbon concentrations, measured at the Zeppelin Mountain as well as on board the Polar 5 aircraft. KW - Arctic KW - Aerosols KW - Lidar KW - Arctic haze Y1 - 2012 U6 - https://doi.org/10.1016/j.atmosenv.2011.11.027 SN - 1352-2310 VL - 52 IS - 3 SP - 56 EP - 66 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Ritter, Christoph A1 - Ángeles Burgos, María A1 - Böckmann, Christine A1 - Mateos, David A1 - Lisok, Justyna A1 - Markowicz, Krzysztof M. A1 - Moroni, Beatrice A1 - Cappelletti, David A1 - Udisti, Roberto A1 - Maturilli, Marion A1 - Neuber, Roland T1 - Microphysical properties and radiative impact of an intense biomass burning aerosol event measured over Ny-angstrom lesund, Spitsbergen in July 2015 JF - Tellus - Series B, Chemical and Physical Meteorology N2 - In this work, an evaluation of an intense biomass burning event observed over Ny-angstrom lesund (Spitsbergen, European Arctic) in July 2015 is presented. Data from the multi-wavelengths Raman-lidar KARL, a sun photometer and radiosonde measurements are used to derive some microphysical properties of the biomass burning aerosol as size distribution, refractive index and single scattering albedo at different relative humidities. Predominantly particles in the accumulation mode have been found with a bi-modal distribution and dominance of the smaller mode. Above 80% relative humidity, hygroscopic growth in terms of an increase of particle diameter and a slight decrease of the index of refraction (real and imaginary part) has been found. Values of the single scattering albedo around 0.9 both at 355nm and 532nm indicate some absorption by the aerosol. Values of the lidar ratio are around 26sr for 355nm and around 50sr for 532nm, almost independent of the relative humidity. Further, data from the photometer and surface radiation values from the local baseline surface radiation network (BSRN) have been applied to derive the radiative impact of the biomass burning event purely from observational data by comparison with a clear background day. We found a strong cooling for the visible radiation and a slight warming in the infra-red. The net aerosol forcing, derived by comparison with a clear background day purely from observational data, obtained a value of -95 W/m(2) per unit AOD500. KW - aerosol KW - lidar KW - retrieval of aerosol properties KW - radiative forcing KW - Arctic aerosol Y1 - 2018 U6 - https://doi.org/10.1080/16000889.2018.1539618 SN - 1600-0889 VL - 70 PB - Routledge, Taylor & Francis Group CY - Abingdon ER - TY - JOUR A1 - Böckmann, Christine A1 - Biele, Jens A1 - Neuber, Roland T1 - Analysis of multi-wavelength lidar data by inversion with mollifier method Y1 - 1998 ER -