Sea Ice Extent
|July 2014||Sea Ice Extent||
|million km2||million mi2||Year(s)||million km2||million mi2|
Data Source: National Snow and Ice Data Center (NSIDC). Period of record: 1979–2014 (36 years)
According to the National Snow and Ice Data Center (NSIDC), the Northern Hemisphere (Arctic) sea ice extent — which is measured from passive microwave instruments onboard NOAA satellites — averaged for July 2014 was 8.25 million square km (3.19 million square miles), 1.45 million square km (560,000 square miles), or 15.0 percent, below the 1981-2010 average. This was the fourth smallest July Arctic sea ice extent on record, with smaller July sea ice extents occurring in 2007, 2011, and 2012. The rate of ice decline during July across the Arctic was near average, with sea ice retreating rapidly at the beginning of the month, but slowing during the second half of the month due to a dramatic shift in the weather patterns across the region. According to the NSIDC, sea ice extent was below average in nearly all regions of the Arctic. Most of the ice along Alaska's coast had melted by the end of the month, except near Barrow. The Northwest Passage remained ice covered, with high ice concentration continuing to cut off the Northern Sea Route. Overall, July Arctic sea ice extent is decreasing at an average rate of 7.2 percent per decade.
The July 2014 Southern Hemisphere (Antarctic) sea ice extent was 17.40 million square km (6.72 million square miles), 0.96 million square km (370,000 square miles), or 5.8 percent, above the 1981-2010 average. This was the largest July Antarctic sea ice extent on record, surpassing the July 2010 Antarctic sea ice extent by 207,000 square km (80,000 square miles). This also marked the 19th consecutive month with much above-average sea ice extent in the Southern Hemisphere and the fourth consecutive month with record large sea ice. Eight of the last 12 months have had record large sea ice extent in the Southern Hemisphere. Southern Hemisphere sea ice extent during July is increasing at an average rate of 1.2 percent per decade.
When combining the Northern and Southern Hemisphere sea ice extents, the globally-averaged sea ice extent during July was 25.65 million square km (9.90 million square miles), 1.8 percent below the 1981-2010 average and the 13th smallest July global sea ice extent on record. Global sea ice extent during July is decreasing at an average rate of 2.0 percent per decade.
For further information on the Northern and Southern Hemisphere snow and ice conditions, please visit the NSIDC News page.