A Two-Stream Multilayer, Spectral Radiative Transfer Model for Sea Ice

• Main Author: Perovich, Donald K
• Other Authors: COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH
• Format: Text
• Language: English
• Published: 1989
• Subjects: Snow; Ice and Permafrost; Radiofrequency Wave Propagation; *RADIATIVE TRANSFER; *REFLECTION; *SEA ICE; *SNOW COVER; RADIATION ABSORPTION; ALBEDO; ARCTIC REGIONS; CASE STUDIES; COVERINGS; CYCLES; EXPERIMENTAL DATA; GEOPHYSICS; LIGHT; LIGHT TRANSMISSION; MELTS; NEAR INFRARED RADIATION; OPTICAL PROPERTIES; RADIATION; REMOTE DETECTORS; VISIBLE SPECTRA; SURFACE PROPERTIES; THERMAL RADIATION; THERMODYNAMICS; THICKNESS; TRANSMITTANCE; VARIABLES; PE61102A; AST24; WU05; Arctic; albedo; Ice; permafrost; Sea ice
• Online Access: http://www.dtic.mil/docs/citations/ADA212433; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA212433

The reflection, absorption, and transmission of light at visible and near-infrared wavelengths is important for a number of geophysical problems. Light reflection is an important parameter in remote sensing studies, absorption is significant to ice thermodynamics, and transmission strongly influences biological activity in and under the ice. The focus of this report is on the reflection and transmission of light by spatially inhomogeneous and temporally varying sea ice covers. This is investigated using a two-stream, multilayer radiative transfer model in the wavelength region from 400 to 1000nm. The model is computationally simple and utilizes the available experimental data on the optical properties of sea ice. The ice cover is characterized as a layered medium composed of selections from nine distinct snow and ice types. Three case studies are presented illustrating values of spectral albedo, transmittance, and transmitted photosynthetically active radiation (PAR) for 1) a spatially inhomogeneous ice cover, 2) a uniform ice cover as it undergoes a melt cycle, and 3) a temporally changing spatially variable ice cover. The importance of thickness and surface conditions on the reflected and transmitted radiation fields is demonstrated. Keywords: Albedo, Arctic, Radiative transfer, Sea ice, Shortwave radiation.