Age of sea ice derived from weekly averaged ice motion vectors. A
value of N indicates ice aged N-1 to N years. A value of 20 represents
land; 21 represents ocean cells where ice age was not calculated. Week
of minimum extent chosen based on NSDIC's Sea Ice Index 5-day
average.

=== Original Data Source ===
https://nsidc.org/data/nsidc-0611

The full original data set provides weekly estimates of sea ice
age for the Arctic Ocean derived from remotely sensed sea ice motion
and sea ice extent. The temporal coverage for this data set is
January 1984 through December 2019. For more recent data, see the
Quicklook Arctic Weekly EASE-Grid Sea Ice Age data product
(https://nsidc.org/data/nsidc-0749). QGreenland displays a subset of
data to coincide with information contained in other sea ice
layers.

Citation:
Tschudi, M., W. N. Meier, J. S. Stewart, C. Fowler, and J.
Maslanik. 2019. EASE-Grid Sea Ice Age, Version 4. [Indicate
subset used]. Boulder, Colorado USA. NASA National Snow and Ice
Data Center Distributed Active Archive Center. doi:
https://doi.org/10.5067/UTAV7490FEPB. 2021/01/05.

Citation URL:
https://doi.org/10.5067/UTAV7490FEPB