Ice that contains liquid water; a composite of ice and liquid water. Spongy ice is a form of accretion of supercooled drops in which the heat transfer is inadequate to freeze all the water. The excess
water is included within the growing ice. Spongy ice may also form during the melting of low-density accretions by the meltwater soaking into the pores.
1. (North-American usage) Permafrost underlying 10 to 35 percent of the exposed land surface; 2.< (Russian usage) Permafrost underlying 5 to 30 percent of the exposed land surface
(1) (North American usage) permafrost underlying 10 - 50% of the exposed land surface (2) (Russian usage) permafrost underlying 5 - 30% of the exposed land surface.
Transient, localized patches of relatively high electron density in the E region of the ionosphere, which significantly affect radiowave propagation. Sporadic E can occur during daytime or nighttime,
and varies markedly with latitude. Es can be associated with thunderstorms, meteor showers, solar, and geomagnetic activity.