As the weight of accumulated snow forces ice lower in the water, more seawater splashes onto the surface and seeps through the snow.

Seawater in the Antarctic often contains higher concentrations of nutrients than does seawater in more temperate regions.

As the air temperature around sea ice decreases during the winter, the likelihood decreases that snow will fall and thus add to any existing snow cover.

The nutrients on which algae rely are common in seawater throughout the Antarctic.

More sunlight filters through a layer of ice than through an equally thick layer of snow.