Tracking the Arctic's shrinking ice cover: Another extreme September minimum in 2004

Abstract

[1] Satellite passive microwave observations document an overall downward trend in Arctic sea ice extent and area since 1978. While the record minimum observed in September 2002 strongly reinforced this downward trend, extreme ice minima were again observed in 2003 and 2004. Although having three extreme minimum years in a row is unprecedented in the satellite record, attributing these recent trends and extremes to greenhouse gas loading must be tempered by recognition that the sea ice cover is variable from year to year in response to wind, temperature and oceanic forcings.

Relaxation of central Arctic Ocean hydrography to pre‐1990s climatology

“…[16] The idea that the 1990s pattern of Arctic change is related to a strengthening of the AO [e.g., Steele and Boyd, 1998;Morison et al, 2000;Karcher et al, 2003] has been cast in doubt by continued decreases in ice extent [e.g., Stroeve et al, 2004] in spite of a decline in AO in the mid-1990s. The persistence of thin ice has been explained in terms of the need for a strongly negative AO to allow sea ice to mature [e.g., Lindsay and Zhang, 2005].…”

Current estimates of freshwater flux through Arctic and subarctic seas

“…The question of long-term thinning, redistribution and retraction of Arctic Sea-ice has been extensively discussed in the literature for example, Rothrock et al (1999), Johannesen et al (1999), Wadhams and Davis (2000), Holloway and Sou (2002), Laxon et al (2003), Rothrock et al (2003), Comiso (2002) and Sroeve et al (2005). The most recent of these (Stroeve et al) shows that the downward trend in ice extent at the annual minimum (September) has been À7.7 ± 3% per decade since 1979 with evidence of a reinforced downturn in the most recent years.…”

An Arctic and antarctic perspective on recent climate change

“…Regionally, this is seen as a retreat in the ice edge of 300-500 km in the Beaufort Sea or the East Siberian Sea, depending on the year. Of particular note are the extreme September ice minima of 2002(Stroeve et al, 2005. Rothrock and Zhang (2004) discuss a decrease in ice thickness.…”