Zero curtain effect

The period of time during which a nearly constant temperature, very close to the freezing point, exists during annual freezing (and occasionally during thawing) of the active layer. when the phase transition between water and ice (or vice versa) is retarded because of the release of the latent heat.

These periods are defined as the date on which the mean daily ground temperatures remain near 0° C for a few days; meanwhile the air temperature varies.

Analysis of thermal data from an arctic site and a mid‐latitude location suggests that the phenomenon may be a universal characteristic of wet, medium‐textured mineral and organic soils during freezing.