Arctic Sea Ice Discussion 2016: Melt Season

[interested & confused]

Weird, I read somewhere in the last few days that the temperature in the Arctic was back down to freezing already *confused* How cold does it have to be to stop losing ice?

[BornFromTheVoid]

Using single day NSIDC extent values, 2016 has now dropped below the minima of every year up to and including 2006, as well and 2009 and 2013. It is also within 35k of 2014.

With the 5 day trailing average, 2016 has now dropped below the minima of every year up to and including 2006, and is just 66.2k off 2009.

...Diff....... No of Years.. Percentage
Below 0........ 28............75.7%
0-100k.......... 1.............2.7%
100-250k....... 2.............5.4%
250-500k....... 0.............0.0%
500-1000k..... 4.............10.8%
>1000k......... 2.............5.4%

[BornFromTheVoid]

21 minutes ago, interested & confused said:

Weird, I read somewhere in the last few days that the temperature in the Arctic was back down to freezing already *confused* How cold does it have to be to stop losing ice?

I thought I'd respond in here, as it's a more suitable thread.
There are a few factors to consider with sea ice. First, is that salt water doesn't freeze until it reaches about -1.8C.
The second factor is that as the surface cools and becomes denser, it sinks, allowing slightly warmer water to rise. This means that you need to cool the first 100m or so of the ocean close to freezing for lasting sea ice to form.
Finally, while some parts of the Arctic will see temps a little below 0C for the next week, that's mainly over areas that already have ice cover. Most of the Arctic is yet to see temps below freezing lasting more than a few days. The current forecast doesn't suggest that sustained sub 0C temperatures will occur across the Arctic until September.

On average, the minimum sea ice coverage occurs about September 12th, so we will still have another 3 weeks or so of melting to go.

[interested & confused]

Thank you for explaining.

[Seanlid]

 

13 hours ago, BornFromTheVoid said:

There are a few factors to consider with sea ice. First, is that salt water doesn't freeze until it reaches about -1.8C.
The second factor is that as the surface cools and becomes denser, it sinks, allowing slightly warmer water to rise. This means that you need to cool the first 100m or so of the ocean close to freezing for lasting sea ice to form.
Finally, while some parts of the Arctic will see temps a little below 0C for the next week, that's mainly over areas that already have ice cover.

 

This is so true, and it's having a major impact on much of the arctic mammals, particularly polar bear! The melting of land-based ice and the expansion of the oceans as they have become warmer account about equally for observed increases in sea level. (Melting of sea ice does not raise sea level, since floating ice already displaces its equivalent in melt water.) Sea level has risen by roughly 17 cm (7 in) in the past 100 years. Although this is a relatively small amount, historical data indicate that mean sea level had been virtually unchanged for the previous 2,000 years. 

[stewfox]

On ‎22‎/‎08‎/‎2016 at 05:50, Seanlid said:

 

This is so true, and it's having a major impact on much of the arctic mammals, particularly polar bear! The melting of land-based ice and the expansion of the oceans as they have become warmer account about equally for observed increases in sea level. (Melting of sea ice does not raise sea level, since floating ice already displaces its equivalent in melt water.) Sea level has risen by roughly 17 cm (7 in) in the past 100 years. Although this is a relatively small amount, historical data indicate that mean sea level had been virtually unchanged for the previous 2,000 years. 

Polar bears may have to wait 2/3 weeks for ice to freeze but no evidence of any impact as numbers increase.

https://polarbearscience.com/2013/07/15/global-population-of-polar-bears-has-increased-by-2650-5700-since-2001/

We should move to Scotland

https://en.wikipedia.org/wiki/Post-glacial_rebound

"""In Great Britain, glaciation affected Scotland but not southern England, and the post-glacial rebound of northern Great Britain (up to 10 cm per century) is causing a corresponding downward movement of the southern half of the island (up to 5 cm per century). This will eventually lead to an increased risk of floods in southern England and south-western Ireland""

[BornFromTheVoid]

After stalling for a few days, NSIDC extent is on the way back down. The single day values are below the minima all but 2007, 08, 10, 11, 12 and 15.

Edited August 24, 2016 by BornFromTheVoid

[stewfox]

4 hours ago, BornFromTheVoid said:

After stalling for a few days, NSIDC extent is on the way back down. The single day values are below the minima all but 2007, 08, 10, 11, and 12.

What percentage extent ? Don't see it on this one ?

https://ads.nipr.ac.jp/vishop/#/extent

[BornFromTheVoid]

3 minutes ago, stewfox said:

What percentage extent ? Don't see it on this one ?

https://ads.nipr.ac.jp/vishop/#/extent

Same 15%, different instruments and algorithms.

However, I forgot to add 2015 on the earlier post, which I presume is why you're asking. Will edit it in now. Otherwise, ADS will be the same on tomorrows update (currently 2.6k above the 2014 min)

[BornFromTheVoid]

An impressive amount of compression and movement toward the Atlantic/Greenland from most of the pack for just 1 day.

The weather patterns that produced this are only going to strengthen over the next 5 days. From this, I'd anticipate an end to the recent melt season "hiatus" and above average extent (and possibly area) losses through the weekend and early next week.

[Singularity]

That's one of the two most shocking images I've seen in a while with respect to the Arctic. The other is the drift map also posted on the ASI forum;

http://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=1493.0;attach=35131;image

Will that entire arm of ice heading into the Atlantic fringes suffer rapid a melt out? That'd be a  big loss... and how much of that is multi-year ice? I suspect more than I'd like to hear.

Deep storms and a dipole pattern combined. I wonder if this pattern is a natural response to having the vast majority of the sea ice on the Canadian side - you you get relatively stable conditions there while a lot of moisture and rising motion fuels storm systems on the Eurasian side.

[BornFromTheVoid]

According to Wipneus' continued update of the CT area, if melting stopped today then 2016 would already have the joint 3rd lowest minimum with 2007. With the potential for a few weeks more melting, just a 15k drop required to be guaranteed of the 2nd lowest minimum on record and some pretty worrying weather now occurring, we're in for a very interesting end to the melt season!

Edited August 25, 2016 by BornFromTheVoid

[BornFromTheVoid]

3 days of compaction

[weirpig]

4 hours ago, BornFromTheVoid said:

3 days of compaction

wow i dont think ive seen such a map as that  the ice seems nearly to have been removed from one side

[Jimmyh]

snow capped hills showing now on this link

http://longyearbyen.kystnor.no/

 

[BornFromTheVoid]

7 minutes ago, weirpig said:

wow i dont think ive seen such a map as that  the ice seems nearly to have been removed from one side

The winds during the weekend are going to get even stronger and squash much of that ice down toward the north coast of Greenland. Given that it's the most fragmented pack for the time of year on record (by several measures), the winds could squash the ice into a much smaller area.

There could even be a little melting too as some anomalously warm air gets pulled in from the Pacific

 

[weirpig]

Just now, BornFromTheVoid said:

The winds during the weekend are going to get even stronger and squash much of that ice down toward the north coast of Greenland. Given that it's the most fragmented pack for the time of year on record (by several measures), the winds could squash the ice into a much smaller area.

There could even be a little melting too as some anomalously warm air gets pulled in from the Pacific

 

Ive also  heard that the potential Typhoon Lionrock could also have some potential damage to the artic  is this correct?

[BornFromTheVoid]

2 minutes ago, weirpig said:

Ive also  heard that the potential Typhoon Lionrock could also have some potential damage to the artic  is this correct?

Probably not. Most of the ensembles have it moving inland over China and quickly dissipating, which would be too far away to influence the Arctic. It would need to maintain some intensity, even transitioning to a hybrid or mid latitude storm, as it gets close to the Arctic circle to have much of an effect.

[weirpig]

2 minutes ago, Nouska said:

The seven day forecast from Mercator Ocean.

http://bulletin.mercator-ocean.fr/en/PSY4#2/62.6/-85.1

 

all that ice being compacted  on our side of the pole  will that in anyway affect the Atlantic sea temps?

[BornFromTheVoid]

2 minutes ago, Nouska said:

The seven day forecast from Mercator Ocean.

http://bulletin.mercator-ocean.fr/en/PSY4#2/62.6/-85.1

 

Looks like there's something off with that. The distribution of ice at the beginning of the model run doesn't match the observational data, a problem with the initialisation data from the ECMWF I guess.

[Nouska]

3 minutes ago, weirpig said:

all that ice being compacted  on our side of the pole  will that in anyway affect the Atlantic sea temps?

I don't know the answer to that - some of the other more knowledgeable posters may help.

There is still a cold sub-surface in the Atlantic and I see the autumn/winter long rangers are returning the cold anomaly (presumably also from storm mixing).

I posted an interesting paper on the jet stream yesterday - among other things, it looks at Arctic ice decline on circulation patterns.

 

[BornFromTheVoid]

Sea ice area taking an absolute hammering the last few days, and is now guaranteed at least the 2nd lowest minimum on record, having dropped about 366k in the last 3 days.

The CT area (if it was still updating) would be down to just 2.81 million km2 now. The 2012 minimum was 2.23 million km2, so it will be interesting to see how close we get.

[weirpig]

30 minutes ago, BornFromTheVoid said:

Sea ice area taking an absolute hammering the last few days, and is now guaranteed at least the 2nd lowest minimum on record, having dropped about 366k in the last 3 days.

The CT area (if it was still updating) would be down to just 2.81 million km2 now. The 2012 minimum was 2.23 million km2, so it will be interesting to see how close we get.

Surely 2012 must be in reach  the conditions over the next few days are not the best 

[BornFromTheVoid]

9 minutes ago, weirpig said:

Surely 2012 must be in reach  the conditions over the next few days are not the best 

For area, the chances have definitely increased, but we're still 600k off the minimum and about 160k off where 2012 was at this point.

But with extent, we're still 1.5 million km2 away from the 2012 minimum. Considering that the most extent lost on record between now and the minimum is 950k back in 1984, we'd have to beat that record by a ridiculous margin. It's also a lot easier to lose a lot of ice, when you have a lot of ice to start out with! Still, given how weak the pack is and the current forecast, I still wouldn't rule it completely

[knocker]

ASI 2016 update 6: hell and high pressure

August 26th 2016

A spectacular start to the melting season is being matched by a spectacular ending. And that's probably putting it mildly.

In the past 10 days we've witnessed a storm that comes close to equalling the Great Arctic Cyclone of 2012 (see the three updates I've written: 1, 2 and 3) and even though cyclonic activity has now lessened, it is still there. Worse still, it is going to be joined by massive high pressure on the American side of the Arctic.

That means - you've guessed it - that the final stage of the melting season will be dominated by a so-called Dipole set-up, where the pressure gradient between the high over the Beaufort Sea and the low over the Siberian Seas is going to have a major impact on the final shape of the ice pack. Just when you thought you had seen it all, the Arctic throws another curve ball.

Although temperatures are now going down and the sun is too low to provide enough energy to melt the ice from the top, massive winds will keep moving the ice around and promote bottom melt. But more importantly, these atmospheric conditions are going to heavily compact the highly dispersed ice pack, and cause some extra transport of ice towards the North Atlantic that is running hotter than ever. It's like putting a plate of biscuits in front of the Cookie Monster (om nom nom).

http://neven1.typepad.com/blog/2016/08/asi-2016-update-6-hell-and-high-pressure.html