Sea ice albedo variability and trend in the Chukchi Sea based on Advanced Very High Resolution Radiometer, 1981 to 2012

We obtained sea ice albedo in Chukchi Sea from the Advanced Very High Resolution Radiometer (AVHRR) (level 1B) after calibration, sun zenith angle correction, narrow-to-broad-band reflectance conversion, anisotropy correction, and atmospheric correction. The results indicate a significant downward trend in the mean sea ice albedo in August from 1981 to 2012. The albedo was between 0.33 and 0.45 prior to 2006. Two historical lows appeared in 2007 and 2012. The sea ice albedo increases with increasing latitude, with the values of approximately 0.15 at latitudes below 70 degrees N and between 0.5 and 0.7 at latitudes above 75 degrees N, where the sea surface is covered with ice. In the area between 70 degrees N and 75 degrees N, the albedo decreases significantly (at 95% significance level) due to the melting of sea ice. As the sea ice extent of August reduced over the past 32 years, the sea ice concentration also decreased, which directly caused the decrease in albedo. Other factors, the increasing temperature, the enlarging fractions of melt ponds, the transition from multiyear ice to seasonal ice, the increasing solar heat input, and the accumulation of black carbon, also play an important role in the albedo decline. (C) 2014 Society of Photo-Optical Instrumentation Engineers (SPIE)