![]() ![]() ![]() Motivation How are MODIS and POLDER ice cloud retrievals different? What is the role of ice particle model? Any implications for climate studies? Is it possible to build up a long-term ice cloud property dataset from multiple missions? MODIS POLDER Resolution 1km 20km Cloud effective radius Retrieved Assumed Ice particle model Baum05 IHM Directionality Single Up to 16 Zhang, Z.et al. Inhomogeneous Hexagonal Monocrystal Constant size (30µm) One habit only Random orientation Internal inclusion of air bubbles Courtesy of Jerome Riedi C.-Labonnote et al GRL Scattering signature consistent with POLDER observationġ9 Scattering phase function Baum05 VS IHMĢ0 Comparison of MODIS and POLDER ice cloud retrieval IWC from MODIS C5 ice particle mode is consistent with in situ measurement Baum et al JAMC Baum et al JAMC More than 1000 PSDs Complicate habit/shape distribution Random orientation Homogeneous and smooth Baum et al JAMC ![]() Inhomogeneity & surface roughness So many things to consider… not surprising that ice particle models are usually different from one another Horizontally orientated Image credit: CNESġ5 Ice particle model Size distribution Shape distribution Orientation Randomly orientated Horizontally orientated Images from 2003 Earth Observing Laboratory NCAR 50 µm Number density Particle Size µm mmĩ Ice particle shape Why shape also matters? Aerosol wavelengthįrom Bryan Baum Why shape also matters? Aerosol wavelength Ice particle wavelength Complicacy of ice particle shape must be acceptable by scattering modelsġ0 Capabilities of current scattering models ![]() 1990) Hard to measure Shattering of large particles Gardiner and Hallett 1985 Gayet et al. 1988 Jensen et al ) Cloud feedback (e.g., Stephens et al. In-situ measurements Scattering model microphysics GCMs Ice Particle Model Satellite remote sensingħ Ice particle model Size distribution Shape distribution OrientationĬloud life time (e.g., Heymsfield 1972, Jensen et al.1996) Cloud reflectance, radiative forcing, heating/cooling rate (e.g., Ackerman et al. Ice clouds are important, because Cover large portion of the Earth’s surface Radiative effects Water vapor budget Cloud feedbacks ISCCP day-time ice cloud amount Earth Albedo Effect Greenhouse Effect (dominant)Ħ Satellite-base remote sensing of ice cloud properties Importance of ice cloud Ice particle model and ice cloud retrieval Influence of ice particle model on t retrieval Comparison of MODIS and POLDER ice t retrieval Influence on our understanding of ice cloud seasonal variability SummaryĤ Ice cloud: important ISCCP day-time ice cloud amount Albedo Effect Influences of ice particle model on ice cloud optical thickness retrieval Zhibo (zippo) Zhang ESSICĢ Outline Background Influence of ice particle model on t retrieval ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |