Sea Ice
Sea Ice Extent
Daily sea ice extent for both hemispheres from satellite passive-microwave observations
(1978–present), from the
NSIDC Sea Ice Index.
Loading sea ice extent data…
Units: Millions of square kilometers (10
6 km²).
Data:
Northern Hemisphere and
Southern Hemisphere
daily extent, NSIDC Sea Ice Index v4 — updated automatically every Monday.
Arctic Sea Ice Volume
Monthly modeled Arctic sea ice volume from
PIOMAS
(Pan-Arctic Ice-Ocean Modeling and Assimilation System, UW Polar Science Center). Unlike the
extent series above, this is a model reanalysis rather than a direct satellite measurement —
see the note below on its current update status.
There is no Southern Hemisphere counterpart on this page: Antarctic sea ice thickness is much
harder to estimate from satellites because of deep, flooding snow cover, so no agency publishes
a routine Antarctic volume time series. The same modeling group's
GIOMAS
project does cover the Antarctic, but only as raw gridded model output — see that page directly
if you want to work with it.
Arctic (PIOMAS)
— ×10³ km³
latest month
Loading sea ice volume data…
Units: Thousands of cubic kilometers (10
3 km³).
Update status: PIOMAS's atmospheric forcing input (NOAA's NCEP/NCAR reanalysis)
was discontinued in March 2026, and the Polar Science Center has not announced a timeline to
resume — the series below may lag behind the present by several months until it does.
Data:
PIOMAS Arctic Sea Ice Volume Reanalysis, UW Polar Science Center.
Schweiger, A., et al. (2011),
J. Geophys. Res., 116, C00D06, doi:10.1029/2011JC007084;
Zhang, J. and D. Rothrock (2003),
Mon. Weather Rev., 131, 845–861.