author = "Krisna, Trismono C. and Wendisch, Manfred and Ehrlich, Andr{\'e} 
                         and J{\"a}kel, Evelyn and Werner, Frank and Weigel, Ralf and 
                         Borrmann, Stephan and Mahnke, Christoph and P{\"o}schl, Ulrich 
                         and Andreae, Meinrat O. and Voigt, Christiane and Machado, Luiz 
                         Augusto Toledo",
          affiliation = "{University of Leipzig} and {University of Leipzig} and 
                         {University of Leipzig} and {University of Leipzig} and 
                         {University of Leipzig} and {Johannes Gutenberg University} and 
                         {Johannes Gutenberg University} and {Johannes Gutenberg 
                         University} and {Max Planck Institute for Chemistry (MPIC)} and 
                         {Max Planck Institute for Chemistry (MPIC)} and {German Aerospace 
                         Center (DLR)} and {Instituto Nacional de Pesquisas Espaciais 
                title = "Comparing airborne and satellite retrievals of cloud optical 
                         thickness and particle effective radius using a spectral radiance 
                         ratio technique: two case studies for cirrus and deep convective 
              journal = "Atmospheric Chemistry and Physics",
                 year = "2018",
               volume = "18",
               number = "7",
                pages = "4439--4462",
                month = "Apr.",
             abstract = "Solar radiation reflected by cirrus and deep convective clouds 
                         (DCCs) was measured by the Spectral Modular Airborne Radiation 
                         Measurement System (SMART) installed on the German High Altitude 
                         and Long Range Research Aircraft (HALO) during the Mid-Latitude 
                         Cirrus (ML-CIRRUS) and the Aerosol, Cloud, Precipitation, and 
                         Radiation Interaction and Dynamic of Convective Clouds System - 
                         Cloud Processes of the Main Precipitation Systems in Brazil: A 
                         Contribution to Cloud Resolving Modelling and to the Global 
                         Precipitation Measurement (ACRIDICON-CHUVA) campaigns. On 
                         particular flights, HALO performed measurements closely collocated 
                         with overpasses of the Moderate Resolution Imaging 
                         Spectroradiometer (MODIS) aboard the Aqua satellite. A cirrus 
                         cloud located above liquid water clouds and a DCC topped by an 
                         anvil cirrus are analyzed in this paper. Based on the nadir 
                         spectral upward radiance measured above the two clouds, the 
                         optical thickness tau and particle effective radius r(eff) of the 
                         cirrus and DCC are retrieved using a radiance ratio technique, 
                         which considers the cloud thermodynamic phase, the vertical 
                         profile of cloud microphysical properties, the presence of 
                         multilayer clouds, and the heterogeneity of the surface albedo. 
                         For the cirrus case, the comparison of tau and r(eff) retrieved on 
                         the basis of SMART and MODIS measurements yields a normalized mean 
                         absolute deviation of up to 1.2% for tau and 2.1% for r(eff). For 
                         the DCC case, deviations of up to 3.6% for tau and 6.2% for r(eff) 
                         are obtained. The larger deviations in the DCC case are mainly 
                         attributed to the fast cloud evolution and three-dimensional (3-D) 
                         radiative effects. Measurements of spectral upward radiance at 
                         near-infrared wavelengths are employed to investigate the vertical 
                         profile of r(eff) in the cirrus. The retrieved values of r(eff) 
                         are compared with corresponding in situ measurements using a 
                         vertical weighting method. Compared to the MODIS observations, 
                         measurements of SMART provide more information on the vertical 
                         distribution of particle sizes, which allow reconstructing the 
                         profile of r(eff) close to the cloud top. The comparison between 
                         retrieved and in situ r(eff) yields a normalized mean absolute 
                         deviation, which ranges between 1.5 and 10.3 %, and a robust 
                         correlation coefficient of 0.82.",
                  doi = "10.5194/acp-18-4439-2018",
                  url = "http://dx.doi.org/10.5194/acp-18-4439-2018",
                 issn = "1680-7316 and 1680-7324",
             language = "en",
           targetfile = "krisna_comparing.pdf",
        urlaccessdate = "25 jul. 2021"