| Term: | First-year ice |
| Definition: |
Floating ice of no more than one year's growth developing from young ice; thickness from 0.3 to 2 meters (1 to 6.6 feet); characteristically level where undisturbed by pressure, but where ridges occur, they are rough and sharply angular. NSIDCCryosphere
Sea ice of not more than one winter's growth, developing from young ice; thickness (typically) 30cm2m. May be subdivided into thin first-year ice/white ice, medium first-year ice and thick first-year ice. ASPECT2012 Sea ice of not more than one winter's growth, developing from young ice; thickness 30 cm - 2 m, and sometimes slightly more. May be subdivided into thin first-year ice/white ice, medium first-year ice and thick first-year ice. Bushuyev Sea ice of not more that one winter's growth, developing from young ice; thickness 1 to 7 ft (30 cm-2 in). May be subdivided into thin first-year ice (white ice), medium first-year ice, and thick first-year ice. WMOSeaIce Sea ice terminology, meaning sea ice that has grown for not more than one winter, developing from young ice. It must also be 30 cm or greater. First-year ice may be subdivided into thin first-year ice (sometimes referred to as white ice), medium first-year ice, and thick first-year ice. ECCCanada Sea ice that has not yet experienced summer melt. First-year ice is distinguished from older ice primarily by having a higher salinity. Undeformed first-year ice differs from older ice in that it is smoother and lacks refrozen melt ponds. First-year ridges are distinguished by being larger, more angular, and more porous than multiyear ridges. AMSglossary Floating ice of not more than one year's growth developing from young ice. Thickness from 30 cm to 2 m. Characteristically level where undisturbed by pressure, but where ridges occur they are rough and sharply angular. SPRI GCW |