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Noordpoolijs bereikte minimum van 2015 op 11 september

Geplaatst: Wo 7 Okt 2015, 12:49
door Martijn
Gisteren heeft het National Snow and Ice Data Center (NSIDS) eindelijk een bericht geplaatst over het smeltseizoen op de noordpool en dat de minimum bedekking van het noordpoolijs werd bereikt op 11 september 2015. Op 15 september kwam het NSIDS al met een voorlopig bericht dat op 11 september het arctische zeeijs waarschijnlijk de minimum bedekking bereikte voor 2015, maar er is dan nog steeds een kans dat er toch nog een lagere ijsbedekking wordt bereikt.

Bron: http://nsidc.org/arcticseaicenews/2015/ ... in-review/

2015 melt season in review

October 6, 2015

The Arctic melt season has ended and sea ice extent is now increasing after reaching the fourth lowest minimum on record, on September 11. Sea ice extent in Antarctica has not yet reached its seasonal maximum.

Overview of conditions

n_extn_hires_resized.png
Figure 1. Arctic sea ice extent for September 2015 was 4.63 million square kilometers (1.79 million square miles). The magenta line shows the 1981 to 2010 median extent for that month. The black cross indicates the geographic North Pole. Credit: National Snow and Ice Data Center.
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Following the seasonal daily minimum of 4.41 million square kilometers (1.70 million square miles) that was set on September 11, which was the fourth lowest in the satellite record, Arctic sea ice has started its cycle of growth. Arctic sea ice extent averaged for the month of September 2015 was 4.63 million square kilometers (1.79 million square miles), also the fourth lowest in the satellite record. This is 1.87 million square kilometers (722,000 square miles) below the 1981 to 2010 average extent, and 1.01 million square kilometers (390,000 square miles) above the record low monthly average for September that occurred in 2012. As of this writing, Antarctica’s winter maximum has not yet occurred, but is anticipated within several days.

Conditions in context

asina_N_stddev_timeseries1_resized.png
Figure 2. The graph above shows Arctic sea ice extent as of October 5, 2015, along with daily ice extent data for four previous years. 2015 is shown in blue, 2014 in green, 2013 in orange, 2012 in brown, and 2011 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. Note: This graph was updated to show the most recent years, in order to be consistent with our monthly posts. Credit: National Snow and Ice Data Center.
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For two weeks following the minimum extent on September 11, air temperatures at the 925 hPa level (about 3,000 feet above the surface) were 2 to 4 degrees Celsius (4 to 7 degrees Fahrenheit) lower than average in the Chukchi and Beaufort seas, helping foster ice growth in those regions. Elsewhere over the Arctic Ocean, there has been fairly little ice growth, in part due to near average to slightly above average air temperatures. Both the Northern Sea Route and Roald Amundsen’s route through the Northwest Passage appeared to remain free of ice at the end of the month. The deeper northern route through Parry Channel, which consists of M’Clure Strait, Barrow Strait, and Lancaster Sound, never completely cleared of ice.

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Zie bron voor volledig artikel met nog meer details over het noordpoolzeeijs en het bereikte minimum.