Arctic Sea Ice Extent, Area, and Volume

[Mallow]

On NSIDC, we're now below 2011, and almost tied with 2007 for second lowest on record.

http://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/

[frontranger8]

6 hours ago, skierinvermont said:

We hear this every year..

You're confusing this with the musings of exceptionally early mins (before 9/5) we hear every year.

You think we'll see a min after 9/12?

[forkyfork]

18 hours ago, frontranger8 said:

You're confusing this with the musings of exceptionally early mins (before 9/5) we hear every year.

You think we'll see a min after 9/12?

what difference does it make? we got to second lowest without an extended summer dipole. that's more worthy of discussion 

[chubbs]

NSIDC extent dropped 120k on 9/6 to 4083k clinching 2nd place.

[bluewave]

James Overland has a nice presentation on the record winter warmth in the Arctic this year which set the stage for the record low sea ice extent levels that were experienced during May. The more favorable polar vortex pattern for sea ice this summer prevented this from being the year which beat 2012. 

 

 

[frontranger8]

5 hours ago, forkyfork said:

what difference does it make? we got to second lowest without an extended summer dipole. that's more worthy of discussion 

And I believe it's being discussed? Geez...ice narrative nazi here.

[Snow_Miser]

NSIDC has now dipped below 2007's minimum, making this year the 2nd lowest minimum on record.

[ORH_wxman]

9/7 would be the earliest extent min on record for Jaxa. I'll have to see what the earliest is for NSIDC. 

[Jonger]

I thought sub 4.0 was a lock on jaxa.

The arctic pulled a Tayshaun Prince block right at the end of the melt season.

 

[Sundog]

13 hours ago, ORH_wxman said:

9/7 would be the earliest extent min on record for Jaxa. I'll have to see what the earliest is for NSIDC. 

I can see why earlier minimums can be more common with very low sea ice numbers since all the easy ice to melt is long gone while in more normal extent years there would have still been some vulnerable ice farther from the core to melt out. 

[forkyfork]

some good animations/graphs here

http://sites.uci.edu/zlabe/arctic-sea-ice-figures/

[ORH_wxman]

50 minutes ago, Sundog said:

I can see why earlier minimums can be more common with very low sea ice numbers since all the easy ice to melt is long gone while in more normal extent years there would have still been some vulnerable ice farther from the core to melt out. 

 

It makes sense anecdotelly, but the lower mins haven't shown to be any earlier than higher mins thus far if we're using empirical evidence. 2007 was actually one of the later mins on record. 2011 was a bit early, but 2012 was pretty late.

I think perhaps the open water this season getting fairly close to the pole but still surrounded by a lot of ice on most sides in the CAB helped cause the early min....assuming we've actually reached the min. The smaller finger of open water there was more vulnerable to closing up quickly once we lost insolation.

 

The higher res U Bremen AMSR2 min occurred even earlier than Jaxa so far...it had a min on 9/1.

[ORH_wxman]

Yeah jaxa had another 78k increase last night...so I think we can call it on jaxa as we are now about 180k above the min...esp given the rate of ice growth seems to be accelerating in the CAB.

[frontranger8]

On 9/5/2016 at 1:00 PM, frontranger8 said:

Given the upcoming pattern, a late minimum (past 9/12) looks very unlikely. Good chance the min is before 9/10.

 

On 9/7/2016 at 7:22 AM, skierinvermont said:

We hear this every year..

I'm such an idiot.

[LithiaWx]

The cheerleading in here by some is patently ridiculous.  We are number two in the record books.  There isn't much to hang a hat on except the date of the min where some can say they were right.  So what?  The ice is still in rough shape.  Low bar is really low.

[frontranger8]

2 hours ago, LithiaWx said:

The cheerleading in here by some is patently ridiculous.  We are number two in the record books.  There isn't much to hang a hat on except the date of the min where some can say they were right.  So what?  The ice is still in rough shape.  Low bar is really low.

I'm not sure you understand "cheerleading". It's all discussion. Move along.

[ORH_wxman]

Now that we've reached the min it looks like on all metrics, time for a quick review.

 

I posted predictions for CT SIA on June 30th this year like I've been doing since 2013. For the first time, this year fell outside the 5-95% confidence intervals. A 5% result would have been a min of 2.58 million sq km on CT SIA, and we finished down near 2.42 million sq km which was actually closer to 2012 (the lowest year) than 2011 (2nd lowest). I'll get back to this in a minute.

For extent, it is a bit harder, but loosely converting area to extent made the low of roughly 4.1 million sq km (on NSIDC...a bit lower on jaxa around 4.02) a result that would occur about 20-25% of the time given the information we had on 6/30. So the extent was low, but not well outside of the typical confidence intervals.

Getting back to the extreme area result....the first culprit you would look at is the weather. However, the weather wasn't hostile to the ice in July/August this summer. There were a few hostile periods, but they were largely transient and we would have needed to see off-the-charts extreme. So weather isn't really a valid explanation. That leaves two other variables that may have played a large factor....bottom melt and reduced ice thickness from an exceptionally warm January-May period. PIOMAS didn't really have exceptionally thin ice, though the CAB region close to the pole was a bit thin and this is actually where a lot of the area damage occurred as we had a big fragmented pool of floes that was the major contributor of the area loss in August. Cryosat2 was a bit thinner here as well. But we've had very thin ice here before too that experienced summer weather worse than 2016 and yet we didn't see this. In 2013, the ice was significantly thinner in much of the CAB region near the pole, though it did have weather more favorable for ice retention than 2016 did. But still, that leads me to believe we may have had more bottom melt too this season. We don't have a lot of reliable data on this. Some scattered buoys is about it. There is some literature that suggests stronger El Ninos causes an influx of warmer waters at depth into the arctic ocean, but it's not very robust.

 

At any rate, it will be interesting to gather more data as it become available in the early winter with cryosat2. I think a combination of exceptional warmth in spring and above average bottom melt likely contributed to the extreme result. Something like this may have to be taken into account in the future when making predictions.

[chubbs]

1 hour ago, ORH_wxman said:

Now that we've reached the min it looks like on all metrics, time for a quick review.

 

I posted predictions for CT SIA on June 30th this year like I've been doing since 2013. For the first time, this year fell outside the 5-95% confidence intervals. A 5% result would have been a min of 2.58 million sq km on CT SIA, and we finished down near 2.42 million sq km which was actually closer to 2012 (the lowest year) than 2011 (2nd lowest). I'll get back to this in a minute.

For extent, it is a bit harder, but loosely converting area to extent made the low of roughly 4.1 million sq km (on NSIDC...a bit lower on jaxa around 4.02) a result that would occur about 20-25% of the time given the information we had on 6/30. So the extent was low, but not well outside of the typical confidence intervals.

Getting back to the extreme area result....the first culprit you would look at is the weather. However, the weather wasn't hostile to the ice in July/August this summer. There were a few hostile periods, but they were largely transient and we would have needed to see off-the-charts extreme. So weather isn't really a valid explanation. That leaves two other variables that may have played a large factor....bottom melt and reduced ice thickness from an exceptionally warm January-May period. PIOMAS didn't really have exceptionally thin ice, though the CAB region close to the pole was a bit thin and this is actually where a lot of the area damage occurred as we had a big fragmented pool of floes that was the major contributor of the area loss in August. Cryosat2 was a bit thinner here as well. But we've had very thin ice here before too that experienced summer weather worse than 2016 and yet we didn't see this. In 2013, the ice was significantly thinner in much of the CAB region near the pole, though it did have weather more favorable for ice retention than 2016 did. But still, that leads me to believe we may have had more bottom melt too this season. We don't have a lot of reliable data on this. Some scattered buoys is about it. There is some literature that suggests stronger El Ninos causes an influx of warmer waters at depth into the arctic ocean, but it's not very robust.

 

At any rate, it will be interesting to gather more data as it become available in the early winter with cryosat2. I think a combination of exceptional warmth in spring and above average bottom melt likely contributed to the extreme result. Something like this may have to be taken into account in the future when making predictions.

It is surprising how close CT SIA came to 2012. The series of storms in August may also have played a role by enhancing bottom melt.

[ORH_wxman]

6 minutes ago, chubbs said:

It is surprising how close CT SIA came to 2012. The series of storms in August may also have played a role by enhancing bottom melt.

 

The powerful August storms could have certainly contributed. It is hard to get a feel for how much though without better data on subsurface water temps under the ice. If the August storms were a major factor, then I may have been too hasty in dismissing the weather as a non-factor.

[skierinvermont]

On 9/13/2016 at 1:49 PM, frontranger8 said:

 

I'm such an idiot.

I didn't disagree.. just skeptical given that we *do* hear it every year (a broken clock is right twice a day) and it would have been a near record early min.

[bluewave]

Statistical tie for 2nd place with 2007 on NSIDC.

http://nsidc.org/arcticseaicenews/

 

Arctic sea ice appears to have reached its seasonal minimum extent for 2016 on September 10. A relatively rapid loss of sea ice in the first ten days of September has pushed the ice extent to a statistical tie with 2007 for the second lowest in the satellite record. September’s low extent followed a summer characterized by conditions generally unfavorable for sea ice loss.

That September ice extent nevertheless fell to second lowest in the satellite record is hence surprising. Averaged for July through August, air temperatures at the 925 hPa level (about 2,500 feet above sea level) were 0.5 to 2 degrees Celsius (1 to 4 degrees Fahrenheit) below the 1981 to 2010 long-term average over much of the central Arctic Ocean, and near average to slightly higher than average near the North American and easternmost Siberian coasts. Reflecting the stormy conditions, sea level pressures were much lower than average in the central Arctic during these months.

Why did extent fall to a tie for second lowest with 2007? The 2016 Arctic melt season started with arecord low maximum extent in March, and sea ice was measured at record low monthly extents well into June. Computer models of ice thickness, and maps of sea ice age both indicated a much thinner ice pack at the end of winter. Statistically, there is little relationship between May and September sea ice extents after removing the long-term trend, indicating the strong role of summer weather patterns in controlling sea ice loss. However, the initial ice thickness may play a significant role. As noted in our mid-August post, the upper ocean was quite warm this summer and ocean-driven melting is important during late summer. The science community will be examining these issues in more detail in coming months.

[ORH_wxman]

Yeah it is interesting they mention the upper ocean heat...I wonder if the exceptionally strong El Nino made it worse this summer than recent years.

[LithiaWx]

4 hours ago, Ufasuperstorm said:

2016 finished 3rd by their metrics.

 

http://nsidc.org/arcticseaicenews/2007/10/589/#26September

 

http://nsidc.org/arcticseaicenews/

 

Additionally, NSIDC always fails to mentioned sea ice extent minimum values before 2012 were based on a nine day trailing mean. Since then we have a 5 day trailing mean, which makes the minimum extent value appear lower than it would be had there been a 9 day trailing mean. The 2016 arctic sea ice extent minimum based on a 9 day trailing mean is 4.18 million square kilometers. For those wondering the daily NSIDC arctic sea ice extent daily minimum value was September 7th, 2016. 

 

Well done NSIDC 

Edit: I encourage you to calculate the 9 day trailing mean from NSIDC's own database below.

ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/north/daily/data/NH_seaice_extent_nrt_v2.csv

Yeah, the whole arctic ice situation really isn't that bad. 

[ORH_wxman]

The distinction between 2007 and 2016 for extent is really not meaningful.

 

This year was definitely worse for area and it is worse for volume.

[bluewave]

16 hours ago, ORH_wxman said:

Yeah it is interesting they mention the upper ocean heat...I wonder if the exceptionally strong El Nino made it worse this summer than recent years.

This will probably be the first melt year that is remembered more for the winter and spring than the summer.

 

 

[chubbs]

 

20 hours ago, ORH_wxman said:

Yeah it is interesting they mention the upper ocean heat...I wonder if the exceptionally strong El Nino made it worse this summer than recent years.

Northern oceans have continued to warm while el-nino fades cooling the tropics. See also:

http://www.esrl.noaa.gov/psd/map/clim/sst.anom.anim.year.html

[Sugarloaf1989]

This YouTube guy is really ridiculous, I posted the webcam to show the true extent of the sea ice at Barrow:

 

 

[lookingnorth]

The ice is growing rapidly, having surpassed 2008, 2007, and 2011.

[Sugarloaf1989]

2 hours ago, lookingnorth said:

The ice is growing rapidly, having surpassed 2008, 2007, and 2011.

That may be but he had a video stating that the Barrow sea ice cam was down to hide the fact of the record freeze up which is false. The cam is working and shows open ocean.

[Jonger]

1 hour ago, Sugarloaf1989 said:

That may be but he had a video stating that the Barrow sea ice cam was down to hide the fact of the record freeze up which is false. The cam is working and shows open ocean.

The jaxa sea ice data doesn't show ice there, what's the conspiracy?