Ice chart definitions

SIC: Sea ice concentration (range: 0-1)
Ice category Ocean: SIC ≤ 0.025[0/10]
Ice category Open water (OW): 0.025 ≤ SIC < 0.125[1/10]
Ice category Very open drift ice (VODI): 0.125 ≤ SIC < 0.35[2/10, 3/10]
Ice category Open drift ice (ODI): 0.35 ≤ SIC < 0.625[4/10, 5/10, 6/10]
Ice category Close drift ice (CDI): 0.625 ≤ SIC < 0.85[6/10, 7/10, 8/10]
Ice category Very close drift ice, Fast ice (VCDI): 0.85 ≤ SIC[9/10, 10/10]
MIZ: Marginal ice zone (categories OW + VODI + ODI + CDI)
Ice edge: Boundary between categories ODI and VODI
Sea ice extent: Area covered with sea ice of categories ODI + CDI + VCDI
MIZ extent: Area covered with sea ice of categories OW + VODI + ODI + CDI