As the sea ice melts, its white reflective surface is replaced by a relatively dark ocean surface. (sciencedaily.com)
As dark ocean surfaces absorb more light than white ice surfaces, solar heat input through the open water melts sea ice, increasing both open water areas and heat input and thus accelerating sea ice melt. (sciencedaily.com)
As sea - ice melts, it exposes a much darker ocean surface, which absorbs more radiation — amplifying the warming. (pnas.org)