Friday, 8 July 2016

Arctic sea ice report - 07/07/2016

2016 Arctic Sea Ice Headed To Zero

Arctic News,
7 July, 2016

The image below shows that Arctic sea ice extent on July 3, 2016, was 8,707,651 square km, i.e. less than the 8.75 million square km that extent was on July 3, 2012.

In September 2012, Arctic sea ice extent reached a record low. Given that extent now is only slightly lower than it was in 2012 at the same time of year, can extent this year be expected to reach an even lower minimum, possibly as low as zero ice in September 2016?

The ice this year is certainly headed in that direction, given that the sea ice now is much thinner than it was in 2012. The image below shows sea ice thickness on July 7, 2012, in the left-hand panel, and adds a forecast for July 7, 2016 in the right-hand panel.

Besides being thinner, sea ice now is also much more slushy and fractured into small pieces. The animation below shows that the sea ice close to the North Pole on July 4, 2016, was heavily fractured into pieces that are mostly smaller in size than 10 x 10 km or 6.2 x 6.2 miles. By comparison, sea ice in the same area did develop large cracks in 2012, but even in September 13, 2012, it was not broken up into small pieces.

One big reason behind the dire state the sea ice is in now is ocean heat. On July 2, 2016, sea surface near Svalbard (at the location marker by the green circle) was as warm as 16.7°C or 62.1°F, i.e. 13.5°C or 24.3°F warmer than 1981-2011. This gives an indication how much warmer the water is that is entering the Arctic Ocean.

As the sea ice disappears, less sunlight gets reflected back into space, resulting in additional warming of the Arctic Ocean. In October 2016, the sea ice will return, sealing off the Arctic Ocean, resulting in less heat being able to escape, at the very time the warmest water is entering the Arctic Ocean from the Atlantic and Pacific Oceans. The danger of this situation is that a large amount of heat will reach the seafloor and destabilize hydrates, resulting in huge abrupt methane releases that will further contribute to warming. When adding in further factors such as discussed e.g. at this earlier post, this adds up to a potential temperature rise of more than 10°C or 18°F compared to pre-industrial times in less than ten years time from now.

The situation is dire and calls for comprehensive and effective action, as described at the Climate Plan.

PIOMAS July 2016

Another month has passed and so here is the updated Arctic sea ice volumegraph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center:
As expected after a month of stalling sea ice extent and weather that generally isn't conducive to sea ice loss, 2016 is no longer lowest on record. In fact, 'only' 5890 km3 of volume was lost during June, according to PIOMAS, which is still more than any year before 2010, but less than any year after 2010, except for 2014. 2016 has now dropped into third position, on a par with 2010.
Here's how the differences with previous years have evolved from last month:
Change monthly difference June
As you can see the change in difference with 2012 is massive, which isn't surprising given that 2012 dropped almost 7300 km3 during June. Over on theArctic Sea Ice Forum I was expecting this year's volume loss to be somewhat higher, but it seems I was wrong. So 2016 is now more than 1000 km3 behind 2012, which is another line of evidence that speaks against new record lows at the end of the melting season. Of course, this doesn't mean everything is hunky dory. Quite the contrary.
Wipneus' version of the PIOMAS volume graph shows how this year's trend line kept veering off its course, while 2012 dropped off a cliff during June:
And look, the trend line on the PIOMAS sea ice volume anomaly graph has dropped well into the 2 standard deviation zone where it hasn't been since 2013. The question is now whether it will drop some more and leave the light grey band like it did in 2010, 2011 and 2012:
The PIOMAS team has again posted a thickness anomaly map that shows where this year the ice is thicker/thinner compared to the 2000-2015 average:
Piomas_thick_anomaly june
Just like last month ice is mostly thicker in the East Siberian and Laptev Sea regions. We get a more detailed view if we compare directly to 2011 and 2012, both currently lower than 2016 and ending with the lowest September volume and extent numbers on record (from this Wipneus comparison map; red means ice is thicker there now, blue the opposite):
SIT difference June
If this year is going to stay in 2011 and 2012's slipstream, it is because a lot of the ice on the Siberian side of the Arctic melts out. But except for an intense heat wave a couple of weeks ago and all the fast ice having disintegrated by now, these regions have been spared the worst, and the current weather forecast isn't showing any big changes in the coming week (more on that in the next ASI update). Plenty of time left to go, of course.
As for average thickness, here's the PIJAMAS graph based on my crude calculation of PIOMAS volume numbers divided by total JAXA sea ice extent:
This year is following the low average thickness years from the 2010-2013 period, as corroborated by the thickness plot from the Polar Science Center:
As a bonus, I'm also showing you a new ice motion map that was posted on thePolar Science Center website, with the January-June mean for the 2006-2016 period on the left, and this year's anomaly to the right:
Although clockwise drift speed has been higher in the Central Arctic during the first half of this year, it doesn't seem to have resulted in as much export through Fram Strait as during the 2006-2016 period. I'm not sure how important this is, as this year the heat has decided to come to the ice, instead of the other way around.
Again, we see how important June is for record-breaking ambitions. These latest PIOMAS numbers show that 2016 has now definitely lost the edge it had over 2012, although it remains one of the lowest in most metrics. I'm still pretty certain that no records will be broken in September, but unfortunately I'm also pretty certain that this year won't offer any relief either. Who knows, maybe a lot of that thicker ice on the Siberian side of the Arctic will be preserved and the Northern Sea Route won't open up completely for the first time in a decade. But somehow I doubt it.

From mid-June onwards, ice cover disappeared at an average rate of 29,000 miles a day, about 70% faster than the typical rate of ice loss, experts say

The summer sea ice cover over the Arctic raced towards oblivion in June, crashing through previous records to reach a new all-time low.

The Arctic sea ice extent was a staggering 260,000 sq km (100,000 sq miles) below the previous record for June, set in 2010. And it was 1.36m sq km (525,000 sq miles) below the 1981-2010 long-term average, according to the National Snow and Ice Data Center.

That means a vast expanse of ice – an area about twice the size of Texas – has vanished over the past 30 years, and the rate of that retreat has accelerated.

Aside from March, each month in 2016 has set a grim new low for sea ice cover, after a record warm winter.

January and February obliterated global temperature records, setting up conditions for the further retreat of the Arctic summer ice cover, scientists have warned.

Researchers did not go so far as to predict a new low for the entire 2016 season. But they said the ice pack over the Beaufort Sea was studded with newer, thinner ice, which is more vulnerable to melting. Ice cover along the Alaska coast was very thin, less than 0.5 meters (1.6 ft).

The loss of the reflective white ice cover in the polar regions exposes more of the absorptive dark ocean to solar heat, causing the water to warm up. This goes on to raise air temperatures, and melt more ice – reinforcing the warming trend.

Scientists have warned the extra heat is the equivalent of 20 years of carbon emissions.

From mid-June onwards, ice cover disappeared at an average rate of 74,000 sq km (29,000 sq miles) a day, about 70% faster than the typical rate of ice loss, the NSIDC said.

Sea ice loss in the first half of the month proceeded at a lower pace, only 37,000 sq km (14,000 sq miles) a day.

The overall Arctic sea ice cover during June averaged 10.60m sq km (4.09m sq miles), the lowest in the satellite record for the month, according to the NSIDC.

There was more open water than average in the Kara and Barents seas as well as in the Beaufort Sea, despite below average temperatures, the NSIDC said.

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