GREEN4SEA Conference & Awards

7 Mar 2018
Learn More
GREEN4SEA Conference & Awards

7 Mar 2018
Learn More

Arctic sea ice extent continues to track well below average

ABS

According to National Snow & Ice Data Center (NSIDC) Arctic sea ice extent continues to track well below average, but it is still unclear whether March will see an increase in ice, or establish a record low maximum. 

Regionally, Arctic ice extent is especially low in the Sea of Okhotsk and the Bering Sea. In the Antarctic, sea ice shrank to the fourth highest minimum in the satellite record.

Overview of conditions

Arctic sea ice extent in February averaged 14.41 million square kilometers (5.56 million square miles). This is the third lowest February ice extent in the satellite record. It is 940,000 square kilometers (362,900 square miles) below the 1981 to 2010 long-term average of 15.35 million square kilometers (5.93 million square miles). It is also 50,000 square kilometers (19,300 square miles) above the record low for the month observed in 2005.

With the Arctic Ocean completely ice covered, the remaining areas of potential new ice growth are limited to the margins of the pack in the northern Pacific and northern Atlantic. Sea ice extent is below average across the entire sea ice margin, most prominently along the Pacific sectors. A small region of above-average ice extent is located near Newfoundland and the Canadian Maritime Provinces.

The Arctic maximum is expected to occur in the next two or three weeks. Previous years have seen a surge in Arctic ice extent during March (e.g., in 2012, 2014). However, if the current pattern of below-average extent continues, Arctic sea ice extent may set a new lowest winter

Conditions in context

Arctic sea ice extent increased by 429,000 square kilometers (165,600 square miles) during the month of February. This gain was slightly less than the average for the month. While low extent for the Arctic as a whole was largely driven by conditions in the Sea of Okhotsk and the Bering Sea, extent was also slightly below average along the Barents Sea and parts of the East Greenland Sea.

February 2015 compared to previous years

The monthly average Arctic sea ice extent for February was the fourth lowest in the satellite record. Through 2015, the linear rate of decline for February extent is 2.9% per decade.

Snow cover

Northern-Hemisphere-Snow-Cover-Feb-2015

This snow cover anomaly map shows the difference between snow cover for February 2015, compared with average snow cover for February from 1981 to 2010. Areas in orange and red indicate lower than usual snow cover, while regions in blue had more snow than normal. (Image Credit: NSIDC)

This unusual jet stream pattern is clearly manifested in the pattern of Northern hemisphere snow cover for February. Snow extent was well above average over the northeastern U.S. However, the western U.S. and Northern Rockies saw less snow cover than average, especially along the Pacific coast where it has been particularly warm and severely dry. While the Tibetan Plateau saw a somewhat more extensive snow cover than average in December and January, extent for Tibet and Eurasia as a whole was below average in February. Higher-than-average snow cover in the eastern U.S. expanded and became more pronounced this month as well. All of these are continuations of the basic pattern seen in December and January, although the pattern of extensive snow over the northeastern U.S. became more pronounced this month. The low snow cover extent in much of Eurasia is consistent with the warmer-than-average conditions there as described above.

Seasonal Antarctic minimum reached

Antarctic sea ice extent reached its annual minimum, dipping to 3.58 million square kilometers (1.38 million square miles) on February 20. This is the fourth highest summer minimum extent on record, trailing behind 2008 (3.75 million square kilometers or 1.44 million square miles, highest), 2013, and 2003. The 2014 Antarctic minimum ranked the fifth highest (3.54 million square kilometers or 1.36 million square miles). For the month as a whole, February 2015 has the sixth highest ice extent (3.8 million square kilometers or 1.46 million square miles).

The sea ice extent trend for February for 1979 to 2015 shows an increase of 5.0%  per decade. However, Antarctica’s sea ice extent is highly variable. As recently as 2011, Antarctic sea ice extent was at near-record low levels for the summer minimum.

Nevertheless, the recent series of high-ice-extent minima is part of a remarkable recent uptick in extent year-round for Antarctica, dominated by extensive ice in both the Weddell Sea (south of Africa) and the Ross Sea (south of New Zealand). Sea ice in the eastern Weddell Sea presently extends several hundred kilometers further north and east of its typical extent, while ice extent in the Ross Sea is presently near average. The debate continues regarding the cause of the recent Antarctic trends, but the best explanation so far involves a combination of strengthening low pressure in the eastern Ross Sea (the Amundsen Sea Low) and the eastern Weddell Sea, and a persistently positive phase of the Southern Annular Mode. The freshening of surface seawater around Antarctica may also play a role.

Global sea ice trends

Claire Parkinson of NASA recently presented the global average (Arctic plus Antarctic) trend in sea ice extent for the period 1979 to 2013. Overall, global sea ice has declined, despite the positive trend in Antarctic extent. The annual average trend is -35,000 square kilometers (-13,500 square miles) per year, or about -1.5% per decade. The strong Arctic decline in September leads to the largest magnitude monthly trend for global sea ice in that month, at -68,000 square kilometers (-26,300 square miles) per year, or -2.6% per decade.

Source : NSIDC

In the outbreak, I was forthright with you propecia before and after has changed my subsistence. It has become much more fun, and now I have to run. Just as it is fabulous to sit.

Related Posts


Share on Facebook0Tweet about this on TwitterShare on Google+0Share on LinkedIn0

Leave a Reply

Your email address will not be published. Required fields are marked *

*

Explore Our Group Sites:

x

Check Also

christophe de margerie yamal lng

Christophe de Margerie starts first commercial voyage for Yamal LNG

The icebreaking LNG carrier 'Christophe de Margerie' completed her first loading of LNG cargo at the Port of Sabetta, on the Yamal Peninsular. The ship is the first in a series of 15 icebreaking LNG carriers ordered for Yamal LNG project, to transport LNG year-round in the challenging ice conditions of the Kara Sea and Gulf of Ob.

The cookie settings on this website are set to "allow cookies" to give you the best browsing experience possible. If you continue to use this website without changing your cookie settings or you click "Accept" below then you are consenting to this. By continuing to use the site, you agree to the use of cookies. more information

The cookie settings on this website are set to "allow cookies" to give you the best browsing experience possible. If you continue to use this website without changing your cookie settings or you click "Accept" below then you are consenting to this. By continuing to use the site, you agree to the use of cookies.more information

Close