Fallen snow preserves dust, ash, bubbles of atmospheric gas and even radioactive elements; a richer source of climatic information than tree rings or layers of sediment.

Removal of atmospheric gas in a more controlled manner could also prove difficult.

As the lift gas heats and expands, the displacement of atmospheric gas increases, while the balloon weight remains constant.

Inclusions in the snow of each year remain in the ice, such as wind-blown dust, ash, pollen, bubbles of atmospheric gas and radioactive substances.

The pressure of an atmospheric gas decreases with altitude due to the diminishing mass of gas above each location.