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Arctic Sea Ice Extent, Area, and Volume


ORH_wxman
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1 hour ago, skierinvermont said:

 

Just put the CO2 back in the atmosphere... we're pretty good at that already without even trying.

The least dangerous and most logical solution is to sequester while drawing down co2 output levels. Carbon based fuels have led to the modern world, don't expect a quick solution to energy needs. We need a combo of all 3.

Reduce co2, sequester existing co2 and reverse warming in the short term with geoengineering.

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Took one of the strongest summer polar vortex patterns over the Arctic of the 2000's to prevent this year from equaling or surpassing 2012.

The most  dramatic  pattern change that you will ever see there following the strongest blocking pattern on record from Jan-May.

JJA.png

 

JM.png

 

 

 

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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 

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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. 

MAY.png

 

 

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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. 

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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.

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AMSR2 Bremen northern hemisphere sea ice concentration map from September 7th - September 12th 2016. Northern hemisphere sea ice extent and sea ice concentration has increased everyday since September 7th, 2016. We are now long past the 2016 northern hemisphere sea ice extent and area minimum values.

 

Septmber%207th%20September%2012th%20GIF_

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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.

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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.

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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.

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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.

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