Parameter Tree:
EARTH SCIENCE > CRYOSPHERE > SEA ICE > POLYNYAS

Definition:
Any non-linear shaped opening enclosed by ice. May contain brash ice and/or
be covered with new ice, nilas or young ice; sub-mariners refer to these
as skylights. Polynyas are important in the study of the energy budget of
the polar ocean and local and regional climatology.


Reference:
Canadian Ice Service - Environment Canada
http://www.cis.ec.gc.ca/manice/chp1_eng.htm .
See also Hall, D.K. and J. Martinec. 1985. Remote Sensing of Ice and Snow,
Chapman and Hall. London.