Recent Trends in Arctic Sea Ice and the Evolving Role of Atmospheric Circulation Forcing, 1979–2007 - Arctic Sea Ice Decline: Observations, Projections, Mechanisms, and Implications - page 12

Plate 2. Geographical distributions of the (top) linear trends and (bottom) climatologies of the dates when sea ice con-
centration first falls below 50% (“melt”), first exceeds 50% (“freeze”), and their difference (“duration”) based on 5-day
running mean data during 199-2006. The trend values are expressed in days per decade, and the climatological values
are expressed in terms of calendar date (number of days for “duration”). The white ellipse around the North Pole indicates
missing data.