edu.ucar.opensky::articles:6423 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-26T15:26:33.368635 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7gq6xx8 The 94-GHz radar dim band: Relevance to ice cloud properties and cloudsat 2008-02-01T00:00:00Z publication https://n2t.org/ark:/85065/d7gq6xx8 https://doi.org/10.1029/2007GL031361 Heymsfield, Andrew J. author Bansemer, Aaron R. author Matrosov, S. author Tian, L. author UCAR/NCAR - Library publisher Details of the microphysics are shown to be responsible for a region of ice cloud which, when probed from above, has decreasing radar reflectivity (Ze ) downwards at 94 GHz but increasing Z e at 9.7 GHz. This 94-GHz radar dim band is found to be due to the combination of ice particle aggregation and non-Rayleigh scattering effects. Observations and model calculations indicate that it occurs when the particle size distribution (PSD) broadens such that its slope, as derived from fitted PSD, decreases below about 15 cm⁻¹, or equivalently, to a median volume diameter exceeding 0.25 cm. Dimming occurs at temperatures (T) primarily between −5 and 0°C but can occur at −30°C or below in convectively-generated ice clouds (anvils). The dimming effect may produce an appreciable low bias in the ice water content (IWC) retrieved from Z measured by CloudSat's 94-GHz radar. Methods to estimate the IWC in the dim band are proposed. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication An edited version of this paper was published by AGU. Copyright 2008 American Geophysical Union. None eng geoscientificInformation