On September 17, Arctic sea ice reached its likely minimum extent for 2014. This is now the sixth lowest extent in the satellite record and reinforces the long-term downward trend in Arctic ice extent. Sea ice extent will now begin its seasonal increase through autumn and winter. Meanwhile, sea ice in the Antarctic has surpassed the previous record maximum extent set in 2013 and is now more than 20 million square kilometers (7.72 million square miles) for the first time in the past thirty-five years. It is too soon to determine if Antarctic sea ice has reached its annual maximum.

Please note that this is a preliminary announcement. Changing winds in the Arctic could still push ice floes together, reducing Arctic ice extent below the current yearly minimum. NSIDC scientists will release a full analysis of the Arctic melt season, and discuss the Antarctic winter sea ice growth, in early October.

Overview of conditions

Figure 1. Arctic sea ice extent for September 17, 2014 was 5.02 million square kilometers (1.94 million square miles). The orange line shows the 1981 to 2010 average extent for that day. The black cross indicates the geographic North Pole. Sea Ice Index data. About the data

Credit: National Snow and Ice Data Center
High-resolution image

On September 17, 2014, sea ice extent dropped to 5.02 million square kilometers (1.94 million square miles). This appears to have been the lowest extent of the year. In response to the setting sun and falling temperatures, ice extent will now climb through autumn and winter. However, a shift in wind patterns or a period of late season melt could still push the ice extent lower. The minimum extent was reached two days later than the 1981 to 2010 average minimum date of September 15.

Conditions in context

Figure 2. The graph above shows Arctic sea ice extent as of September 17, 2014, along with daily ice extent data for four previous years. 2014 is shown in blue, 2013 in green, 2012 in orange, 2011 in brown, and 2010 in purple. The 1981 to 2010 average is in dark gray. The gray area around the average line shows the two standard deviation range of the data. Sea Ice Index data.

Credit: National Snow and Ice Data Center
High-resolution image

This year’s minimum was 1.61 million square kilometers (622,000 square miles) above the record minimum extent in the satellite era, which occurred on September 16, 2012, and 1.20 million square kilometers (463,000 square miles) below the 1981 to 2010 average minimum.

Varying distribution of ice in 2014 versus 2013

Figure 3. This image compares differences in ice-covered areas between September 17, 2014, the date of this year’s minimum, and last year’s minimum, September 13, 2013. Light gray shading indicates the region where ice occurred in both 2014 and 2013, while white and dark gray areas show ice cover unique to 2014 and to 2013, respectively. Sea Ice Index data. About the data

Credit: National Snow and Ice Data Center
High-resolution image

This year, the ice cover remained more extensive over the Barents and Kara seas compared to last year. The most notable feature was the lack of ice north of the Laptev Sea that at one point in the melt season extended beyond 85 degrees North latitude, within 550 kilometers (342 miles) of the North Pole. This year was also unusual compared to recent years in that the Northwest Passage remained closed. On the other side of the Arctic, the Northern Sea Route or Northeast Passage opened with little ice near most of the shipping route along the coast of Siberia.

Antarctic overview and conditions

Figure 4. Antarctic sea ice extent for September 20, 2014 was 20.07 million square kilometers (7.75 million square miles). The orange line shows the 1981 to 2010 average extent for that day. The black cross indicates the geographic South Pole. Sea Ice Index data. About the data

Credit: National Snow and Ice Data Center
High-resolution image

While it is too soon to tell if sea ice around Antarctica has reached its annual maximum for the winter, it remained at record high daily levels for most of the year. On September 19, the five-day average ice extent surpassed 20 million square kilometers (7.72 million square miles) for the first time in the satellite record. Ice extent is above average in almost all sections of the Antarctic, particularly in the northern Ross Sea and Indian Ocean sectors. Near-average ice extent occurs south of South America in the northern Bellingshausen Sea and in a small region south of Australia.

Figure 5. The graph above shows Antarctic sea ice extent as of September 20, 2014, along with daily ice extent data for four previous years. 2014 is shown in blue, 2013 in green, 2012 in orange, 2011 in brown, and 2010 in purple. The 1981 to 2010 average is in dark gray. The gray area around the average line shows the two standard deviation range of the data. Sea Ice Index data.

Credit: National Snow and Ice Data Center
High-resolution image

Previous minimum Arctic sea ice extents

The end of this year’s Arctic sea ice melt season is imminent and the minimum extent will be slightly lower than last year’s, making it the sixth lowest extent in the satellite record. Earlier in the month, a small area of the Laptev Sea ice edge was within five degrees of the North Pole. This appears to be the result of persistent southerly winds from central Siberia. Meanwhile, Antarctic sea ice is poised to set a record maximum this year, now at 19.7 million square kilometers (7.6 million square miles) and continuing to increase.

Overview of Conditions

Figure 1. Arctic sea ice extent for September 15, 2014 was 5.07 million square kilometers (1.96 million square miles). The orange line shows the 1981 to 2010 average extent for that day. The black cross indicates the geographic North Pole. Sea Ice Index data. About the data

Credit: National Snow and Ice Data Center
High-resolution image

Arctic sea ice extent for September 15 was 5.07 million square kilometers (1.96 million square miles). This is only 30,000 square kilometers (11,600 square miles) below the same date last year, yet sea ice extent remains low compared to the long-term 1981 to 2010 average. As is typical for this time of year, weather conditions near the ice edge heavily influence the timing of the minimum, which has occurred as late as September 23. We are now a day past the 1981 to 2010 average minimum date of September 15.

Conditions in context

Figure 2. The graph above shows Arctic sea ice extent as of September 15, 2014, along with daily ice extent data for four previous years. 2014 is shown in blue, 2013 in green, 2012 in orange, 2011 in brown, and 2010 in purple. The 1981 to 2010 average is in dark gray. Sea Ice Index data.

Credit: National Snow and Ice Data Center
High-resolution image

Sea ice extent declined at a rate of 28,700 square kilometers (11,100 square miles) per day through the first half of September. This is nearly twice as high as the 1981 to 2010 average rate of decline for this period of 16,200 square kilometers (6,200 square miles) per day. As was the case for the beginning of the month, extent remains below average in all sectors of the Arctic except for a region in the Barents Sea, east of Svalbard. There are areas of fairly low concentration ice north of the East Siberian and Chukchi seas that may still melt out or compact from wind-driven drifting.

However, as in 2013, a large area in the East Siberian Sea remains ice covered, helping to keep the overall extent higher for this time of year than observed since 2007. Last summer that area was covered by first-year ice that did not melt out under cooler-than-average conditions. This year, a region of second-year ice appears to have helped stabilize ice loss there.

The Northwest Passage remains closed, while the Northern Sea Route is still largely clear of ice.

A new ice edge

Figure 3a. The map at top shows the ages of ice in the Arctic at the beginning of March 2014; the bottom graph shows how the percentage of ice in each age group has changed from 1983 to 2014 .

Credit: NSIDC, courtesy M. Tschudi, University of Colorado
High-resolution image

Through the first half of September, the ice edge slowly retreated north of the Laptev Sea and is now within five degrees latitude of the North Pole. This is the most northerly position that the ice edge has been recorded over the period of satellite observations in this region. A large part of this region was also ice free in 2007. The reasons for the strong ice retreat in this sector are, at present, not entirely clear but we offer some initial insights.

Figure 3b. This map shows surface wind patterns over the Arctic region from June to August 2014.

Credit: NSIDC courtesy NOAA/ESRL Physical Sciences Division
High-resolution image

In April, we discussed the pattern of ice age across the Arctic as the melt season began. In general, younger ice tends to be thinner ice. Areas of young ice are more likely to melt out during the summer than areas of old ice. The ice age figure from that post, reproduced here (Figure 3a), shows a strong northward extension of ice less than one year of age along the same general longitudes that open water has developed. Given the general circulation of the sea ice away from the Siberian shores, this area of thin ice prone to melting out would have tended to advance further northward through the melt season. Indeed, average sea level pressures this summer featured a pattern of surface winds particularly conducive to transporting thinner ice northward in the Laptev Sea sector (Figure 3b). To the east, winds were calmer and an arm of older, thicker second-year ice there may have helped to limit melt out and northward advection.

Sea surface temperature update

Figure 4. These maps show Arctic sea surface temperatures (left) and temperature anomalies (right) for August 2014, in degrees Celsius. Sea surface temperature data are from the National Climatic Data Center’s OIv2 “Reynolds” data set, a blend of satellite (Advanced Very High Resolution Radiometer) and in situ data designed to provide a bulk or mixed layer temperature. Ice edge data are from NSIDC near-real time passive microwave data.

Credit: Mike Steele/University of Washington
High-resolution image

As one may expect with an early retreat of sea ice, sea surface temperatures in the Laptev Sea were higher than average by up to 5 degrees Celsius (9 degrees Fahrenheit), with up to 3 degrees Celsius (5 degrees Fahrenheit) anomalies extending north of 80 degrees North for the first time since 2007. Early ice retreat and high sea surface temperatures are not unusual for this area and have appeared every summer since 2007, with the exception of 2008. The date of ice opening in the Laptev Sea is not particularly unusual in 2014 either. Open water and warming ocean temperatures started in early June. However, this summer there was a rapid northward progression of the ice edge in this area, especially along about longitude 140 degrees East, which allowed the sun to warm the resulting open water.

Over other parts of the Arctic, sea surface temperatures were not particularly noteworthy, except for cooler-than-average conditions in the northern Barents and Kara seas where the ice has remained extensive compared to recent summers. This reverses a recent trend toward warming and ice retreat in these areas, noted in last year’s sea surface temperature update. Preliminary analysis indicates that these changes are forced by local meteorological conditions, rather than oceanic heat transport by Atlantic water.

Further reading

Steele, M., S. Dickinson, and J. Zhang. 2014. Seasonal ice loss in the Beaufort Sea: Toward synchronicity and prediction. Journal of Geophysical Research-Oceans. In review.

The Arctic summer of 2014 is nearing an end. Overall, the rate of ice loss during August was near average. Regions of low concentration ice remain in the Beaufort and East Siberian seas that may yet melt out or compress by wind action. While the Northwest Passage continues to be clogged with ice and is unlikely to open, the Northern Sea Route along the Siberian coasts appears open except for some ice around Severnaya Zemlya. As the end of the southern winter draws closer, Antarctic sea ice extent remains higher than average.

Overview of conditions

Figure 1. Arctic sea ice extent for August 2014 was 6.22 million square kilometers (2.40 million square miles). The magenta line shows the 1981 to 2010 median extent for that month. The black cross indicates the geographic North Pole. Sea Ice Index data. About the data

Credit: National Snow and Ice Data Center
High-resolution image

Sea ice extent in August 2014 averaged 6.22 million square kilometers (2.40 million square miles). This is 1.00 million square kilometers (386,000 square miles) below the 1981 to 2010 August average, but well above the 2012 August average of 4.71 million square kilometers (1.82 million square miles). Extent was below average throughout the Arctic except for a region in the Barents Sea, east of Svalbard. The ice edge continued to retreat north of the Laptev Sea, and is now within 5 degrees latitude of the North Pole.

Conditions in context

Figure 2. The graph above shows Arctic sea ice extent as of September 1, 2014, along with daily ice extent data for four previous years. 2014 is shown in blue, 2013 in green, 2012 in orange, 2011 in brown, and 2010 in purple. The 1981 to 2010 average is in dark gray. Sea Ice Index data.

Credit: National Snow and Ice Data Center
High-resolution image

August ice extent declined at an average rate of 54,300 square kilometers (21,000 square miles) per day. This was slightly less than the average rate for the month. Generally, the decline slows in August as the Arctic sun dips lower in the sky. Recent years have been an exception, with relatively fast ice loss rates in August.

August 2014 compared to previous years

Figure 3. Monthly August ice extent for 1979 to 2014 shows a decline of 10.3% per decade relative to the 1981 to 2010 average.

Credit: National Snow and Ice Data Center
High-resolution image

Despite the near-average rate of decline in ice extent through the month, August 2014 ended up with the 7th lowest extent in the satellite record. It is 1.51 million square kilometers (583,000 square miles) above the record low for August 2012 and is also higher than August of 2007, 2008, 2010, 2011, and 2013. The monthly linear rate of decline for August over the satellite record is now 10.3 percent per decade.

The Northwest Passage: closed for business

Figure 4. This time series shows the total sea ice area for selected years within the Western Parry Channel route of the Northwest Passage. The cyan line shows 2014, and other colors show ice conditions in different years.

Credit: S. Howell/Environment Canada
High-resolution image

Several recent years have seen remarkably open conditions in the Northwest Passage by the end of August. This year, however, much of the passage is clogged with ice, and even the circuitous Amundsen route is not entirely open. (Note that Amundsen required two summers to navigate this route in 1905; Amundsen wintered over in the hamlet of Gjoa Haven—now called Uqsuqtuuq).

The recent openings of the Northwest Passage in 2007, 2008, 2010, and 2011 were associated with high sea level pressure anomalies over the Beaufort Sea and Canadian Basin. This atmospheric pattern essentially displaces the polar pack away from the M’Clure Strait, resulting in minimal ice inflow from the Arctic Ocean. In contrast, weather patterns this year have been more moderate, and as a result, more ice remains in the Northwest Passage. As of the end of August 2014, ice area in the passage was tracking above the 1981 to 2010 average. Ice area over the summer of 2013 tracked slightly below the 1981 to 2010 average, but was considerably higher than the years prior. The summer of 2011 saw the lowest ice area in the Northwest Passage since 1968.

On the other side of the Arctic Ocean, conditions are much more open along the Northeast Passage (also known as the Northern Sea Route). There are wide areas of open water along much of the Russian Arctic coast, the lone exception being the area around Severnaya Zemlya.

Reference

Howell, S. E. L., T. Wohlleben, M. Dabboor, C. Derksen, A. Komarov, and L. Pizzolato. 2013. Recent changes in the exchange of sea ice between the Arctic Ocean and the Canadian Arctic Archipelago, J. Geophys. Res. Oceans, 118, 3595-3607, doi:10.1002/jgrc.20265.