Modeling of ice albedo: A quantitative study of the impact of surface roughness

The effects of surface roughness on spectral and broadband (spectrally integrated) albedos of sea ice are investigated using a multiple scattering radiative transfer model for the atmosphere-snow/ice system (ARTMASS2). The model accounts for multiple scattering, incorporating Mie theory and geometric optics approximation for single scattering by various components such as snow grains, air bubbles, brine pockets, and cloud droplets across a wavelength range from 0.3 to 4.0μm. To account for the refractive index change at the air-ice interface, we introduced an ice surface reflection model. Recognizing the irregularity of sea ice surfaces, we integrated surface roughness into this model. Our findings indicate that sea ice surface roughness can significantly alter both spectral and broadband albedos. Particularly for bare sea ice, surface roughness plays a significant role in albedo variation.