Global sea ice coverage from satellite data: Annual cycle and 35-yr trends

Abstract

Well-established satellite-derived Arctic and Antarctic sea ice extents are combined to create the global picture of sea ice extents and their changes over the 35-yr period 1979-2013. Results yield a global annual sea ice cycle more in line with the high-amplitude Antarctic annual cycle than the lower-amplitude Arctic annual cycle but trendsmore in linewith the high-magnitude negativeArctic trends than the lower-magnitude positive Antarctic trends. Globally,monthly sea ice extent reaches a minimumin February and amaximum generally in October or November. All 12 months show negative trends over the 35-yr period, with the largest magnitude monthly trend being the September trend, at -68 200 ± 10 500 km2 yr-1 (-2.62% ± 0.40% decade-1), and the yearly average trend being 2-35 000 ± 5900 km2 yr-1 (11.47% ± 0.25% decade-1).