Spectral albedo of snow-covered first-year and multi-year sea ice during spring melt

Abstract

Surface spectral-albedo data collected over snow-covered first-year and multi-year sea ice under diffuse sky conditions during the springtime transition are examined. Of specific interest is the relationship between changes in the visible and near-infrared albedo of sea ice and concurrent changes in the geophysical characteristics of the ice volume. With the onset of melt conditions, visible and near-infrared sea-ice albedo decreased due to physical changes within the snow and ice volumes. Visible albedo was found to be sensitive to changes occurring throughout the sea-ice volume, while the near-infrared albedo appeared most influenced by near-surface conditions.

Airborne spectral measurements of surface-atmosphere anisotropy for arctic sea ice and tundra

“…Several studies of sea ice re ective characteristics have been reported (Grenfell and Maykut 1977, Grenfell and Perovich 1984, Perovich et al 1986, Allison et al 1993, DeAbreu et al 1995. These sea ice studies, using typically ground-based instrumentation in mostly diVuse light conditions (overcast sky), discuss sea ice characteristics and their spatial and temporal eVects on both spectral and wavelengthintegrated albedo.…”

Airborne observations of summertime surface features and their effect on surface albedo during FIRE/SHEBA

“…During the arctic summer the absorption of solar radiation by sea ice and, consequently, its melt rate, is accelerated by the ibnnation of melt ponds and open water. Measurements of melt pond characteristics [Perovich, 1998;Morassutti and LeDrew, 1996;De Abreu et al, 1995] have shown that ponds serve to substantially lower the albedo froin typical values relative to bare or snow-covered ice. This reduction in albedo was also observed during the Surface Heat Budget of the Arctic Ocean (SHEBA) experiment [Perovich et al, 1999a].…”

Bidirectional anisotropic reflectance of snow and sea ice in AVHRR channel 1 and channel 2 spectral regions. II. Correction applied to imagery of snow on sea ice

“…is the calibration slope given by (4) and (5) in [15], which is a function of day number after the launch of the NOAA 14 satellite and is expressed as…”

“…Consistent with the derivation of the isotropic albedo from satellite radiance [15], we first calculate the radiance at direction ( , ), where , and represent the solar zenith, the view zenith, and the relative azimuth angles, respectively. Then, the modeled isotropic albedo is given as (4) where…”

“…Therefore, accurate assessment of the amount of reflected solar radiation over snow/ice covered ocean is needed [1]- [3]. Although many in situ measurements of snow albedo have been made (e.g., [4]- [6]), we have to rely on satellite observations for large-scale, high spatial, and temporal coverage Manuscript received March 5, 1999; revised July 6, 1999. This work was supported by the Marine Life Research Group of the Scripps Institution of Oceanography, a NASA GMS Pathfinder project and a NASA WP-ESIP Federation project.…”