Simulation of the optical properties of plate aggregates for application to the remote sensing of cirrus clouds

摘要: In regions of deep tropical convection, ice particles often undergo aggregation and form complex chains. To investigate the effect representation aggregates on electromagnetic scattering calculations, we developed an algorithm to efficiently specify geometries compute some their geometric parameters, such as projected area. Based in situ observations, are defined clusters hexagonal plates with a chainlike overall shape, which may have smooth or roughened surfaces. An aggregate is 10 ensemble members, each consisting between 4–12 plates. The properties individual particle computed using either discrete dipole approximation improved optics method, depending upon size parameters. Subsequently, averaged over all geometries. closely agree those from 1000 different As result, provides accurate computationally efficient way represent occurring within clouds. Furthermore, can be used study influence these satellite-based remote sensing cloud reflectances for associated randomly oriented When neglected, simulated generally lower at visible shortwave-infrared wavelengths, resulting smaller effective sizes but larger optical thicknesses.