Eisschmelze

Eisschmelze is the process by which solid water (ice) transforms into liquid water. The term is used in physics, glaciology, climatology, and engineering to describe melting in natural systems such as glaciers, sea ice, and seasonal snow, as well as in artificial contexts like frozen storage or cooling systems. In climate science, Eisschmelze is a key component of ablation, sea-level change, and regional hydrology.

Under standard conditions, pure ice melts at 0°C at 1 atmosphere of pressure. The transformation requires latent heat of fusion of about 333.55 kilojoules per kilogram. Ice is less dense than liquid water; for the same mass, ice occupies a larger volume, so melting reduces volume by roughly 8% as ice becomes water. The melting point of ice is sensitive to pressure and impurities: increased pressure lowers the melting point slightly for ice Ih, and dissolved substances such as salt can lower it substantially, allowing melt at subfreezing temperatures in saline environments.

In natural settings, Eisschmelze occurs via surface melting, internal melting, and basal melting. Solar radiation, air temperature, and heat conduction through the ice drive surface melt; meltwater can percolate and lubricate the ice base, enhancing flow in glaciers. In sea ice, salinity creates brine pockets that melt at subfreezing temperatures, influencing stability and dynamics. Eisschmelze also interacts with albedo feedback: darker exposed water and melt ponds absorb more solar energy, accelerating further melting.

The climate impact of Eisschmelze is significant. Melt of glaciers and ice sheets raises global sea level, while changes in sea-ice extent alter ocean circulation and regional climates.