Arctic Sea Ice Extent, Area, and Volume

[forkyfork]

2 hours ago, chubbs said:

Big area losses in the CAB the past couple of days. With the stormy pattern forecast to persist for the next week, may get open water close to the pole.

-285k in two days

[Sophisticated Skeptic]

sounds like stuffs gettin ripped up. 

[csnavywx]

To finish 2nd, shadow CT needs to drop 326k from its current readings. (It would need 996k for 1st.) The next few days look fairly cold and stormy, but the EPS shows conditions favorable for melt from D5 onwards. As weak as the remnant ESS arm of the pack is at the moment, I would expect almost all (if not entirely all) of that part to melt off. The Laptev arm isn't looking too hot either, but it's late enough that it'll probably survive in some fashion. At this time, a solid 2nd place finish looks good. Pretty remarkable, considering the vast majority of the summer remained colder than normal.

[Sophisticated Skeptic]

It's an unusually cold and stormy pattern though.

the winds have to be the only reason, right ?

[stadiumwave]

6 hours ago, csnavywx said:

To finish 2nd, shadow CT needs to drop 326k from its current readings. (It would need 996k for 1st.) The next few days look fairly cold and stormy, but the EPS shows conditions favorable for melt from D5 onwards. As weak as the remnant ESS arm of the pack is at the moment, I would expect almost all (if not entirely all) of that part to melt off. The Laptev arm isn't looking too hot either, but it's late enough that it'll probably survive in some fashion. At this time, a solid 2nd place finish looks good. Pretty remarkable, considering the vast majority of the summer remained colder than normal.

Considering where we started I think it's remarkable that this year wasn't a record melt!

[ORH_wxman]

11 minutes ago, stadiumwave said:

Considering where we started I think it's remarkable that this year wasn't a record melt!

 

You can look at it both ways this year...we had a record warm spring (after a record warm winter) and June actually wasn't that cold...maybe slightly below normal, but it ranked like 19th or something since 1979. 2013 and 2014 ranked in the top 5 coldest. There was unprecedented open water on the pacific side early in the season. So the ice came into this summer in about the worst shape it could have given the starting point at the end of last melt season. Yet, we're not going to come close to the record.

 

On the other hand, July and August have been cold and yet we're still challenging the 2nd lowest season. So that sounds impressive too.

 

 

It will be a race between the ESS arm of ice melting down and the CAB slush pool refreezing late this month that determines the exact spot we finish.

 

 

[forkyfork]

area is only 44k above 2012 at this point

[ORH_wxman]

9 minutes ago, forkyfork said:

area is only 44k above 2012 at this point

 

CT SIA (or really NSIDC area) is something like 400k above 2012 actually.

 

 

[A-L-E-K]

lol @ forky

[forkyfork]

1 hour ago, ORH_wxman said:

 

CT SIA (or really NSIDC area) is something like 400k above 2012 actually.

 

 

i was using the amsr2 numbers from wipneus 

[ORH_wxman]

7 minutes ago, forkyfork said:

i was using the amsr2 numbers from wipneus 

 

Doesn't he use SSMI/S for 2012 though? That would not be the best comparison.

If those numbers are accurate though, then they will show up on most metrics very soon. I'm a bit skeptical on that though.

 

I do think there's higher than normal risk for a late crash given all the marginal concentration....but on the flip side, I could see a pretty big area spike if that stuff near the pole starts to refreeze in the next 4-6 days. That's a difficult area to keep low concentration this late.

[stadiumwave]

7 hours ago, ORH_wxman said:

 

You can look at it both ways this year...we had a record warm spring (after a record warm winter) and June actually wasn't that cold...maybe slightly below normal, but it ranked like 19th or something since 1979. 2013 and 2014 ranked in the top 5 coldest. There was unprecedented open water on the pacific side early in the season. So the ice came into this summer in about the worst shape it could have given the starting point at the end of last melt season. Yet, we're not going to come close to the record.

 

On the other hand, July and August have been cold and yet we're still challenging the 2nd lowest season. So that sounds impressive too.

 

 

It will be a race between the ESS arm of ice melting down and the CAB slush pool refreezing late this month that determines the exact spot we finish.

 

 

 

Agree on both accounts

[DaculaWeather]

Anyone know what happened to the Rutgers site?

[frontranger8]

Ice loss has slowed the past few days, as expected. No Icepocalypse, nothing like 2012.

[ORH_wxman]

1 hour ago, Ufasuperstorm said:

We have gained sea ice extent and sea ice area; each of the last two days. (Today should make a 3rd) We are now 25.5 thousand square kilometers and 87.7 thousand square kilometers, with respect to extent and area, above the 2016 minimum values. 

 

 

We gained area on today's update but we didn't gain extent on any of the main datasets. I'm not sure which datasets you are using to get those numbers. 

[ORH_wxman]

54 minutes ago, Ufasuperstorm said:

Wipneus AMSR2 extent & area calculation

 

Ahhh...right. I don't usually use those since they have no real history (only back to 2013 AMSR2).

Though the bootstrap AMSR2 data from U Bremen does look like a slowdown the last couple days:

 

 

 

 

The ice still looks pretty precarious though so I wouldn't be surprised if we see some big drops between now and the min. I don't know if it will be enough to finish below 2011, 2015, or 2007...but we'll see. You can see on the graph how 2015took a really steep dive starting this week.

[stadiumwave]

6 hours ago, frontranger8 said:

Ice loss has slowed the past few days, as expected. No Icepocalypse, nothing like 2012.

 

Folks who were hoping for 2012 cyclone repeat forget that volume is better than that summer.

[frontranger8]

1 hour ago, stadiumwave said:

 

Folks who were hoping for 2012 cyclone repeat forget that volume is better than that summer.

And that pattern was much different than the one we've been in the past few days. Much smaller cyclone, stronger, and not nearly as cold.

Looks like a dipole develops next, though, so should see losses pick up again soon. But we're well past peak melting season, so that's the good news (if you're rooting for ice survival rather than annihilation).

 

[The_Global_Warmer]

The ice has been smoked.  Now an absolutely filthy warm wind field is forming.Gonna end up in 2nd place

[bluewave]

This is officially the slowest melt season from June 21st to August 21st on NSIDC going back to 2007.

The only reason we are challenging 2nd or 3rd place is due to the record warmth and dipole pattern

from the winter into spring. The 2012 record low will last at least 5 years just like the 2007 record low did.

 

NSIDC 6/1-8/21 loss since 2007

2016...6005

2015...6328

2014...6369

2013...6599

2012...7944

2011...6735

2010...6247

2009...6451

2008...6585

2007...7156

[chubbs]

10 hours ago, frontranger8 said:

And that pattern was much different than the one we've been in the past few days. Much smaller cyclone, stronger, and not nearly as cold.

Looks like a dipole develops next, though, so should see losses pick up again soon. But we're well past peak melting season, so that's the good news (if you're rooting for ice survival rather than annihilation).

 

You were thinking 4-6'th at the start of the stormy period. Is that still your call?

[frontranger8]

6 hours ago, chubbs said:

You were thinking 4-6'th at the start of the stormy period. Is that still your call?

It was actually prior that I said that. Probably depends on how long the dipole persists. Hard to say, given that it's a pretty destructive pattern, but coming so late in the season. I'd probably say 3rd-5th is most likely at this point for area, at least.

[chubbs]

1 hour ago, frontranger8 said:

It was actually prior that I said that. Probably depends on how long the dipole persists. Hard to say, given that it's a pretty destructive pattern, but coming so late in the season. I'd probably say 3rd-5th is most likely at this point for area, at least.

Yes dipole would be much worse in June or July. I favor 2 or 3 on area.

[csnavywx]

Probably surface pond re-freeze. The upcoming pattern features a +3-4SD ridge (570-582 dam) over the CAB and a -2SD low near the Kara, so the upcoming week should feature some significant late losses. It may be enough to lock a 2nd place finish, but we'll see.

[chubbs]

On 8/23/2016 at 11:01 PM, csnavywx said:

Probably surface pond re-freeze. The upcoming pattern features a +3-4SD ridge (570-582 dam) over the CAB and a -2SD low near the Kara, so the upcoming week should feature some significant late losses. It may be enough to lock a 2nd place finish, but we'll see.

Could also be cloud/precip/ice movement since it reversed last night with a 147k amsr2 area drop. Day-to-day trends have been variable but area is still dropping at a good clip averaged over the past week or so.

[bluewave]

It took the strongest summer Arctic polar vortex since 1996 for the slowest June into late August melt season since 2007  on NSIDC.

The polar vortex was actually stronger than we saw in 2013.

 

 

 

 

 

 

[ORH_wxman]

7 minutes ago, bluewave said:

It took the strongest summer Arctic polar vortex since 1996 for the slowest June into late August melt season on NSIDC.

The polar vortex was actually stronger than we saw in 2013.

 

 

 

 

 

 

 

 

 

 

 

Looks like it was displaced a bit too much toward the Asian side though to produce the type of cold we saw in those other seasons. (1996 had the coldest June/July on record and 2013 was top 5) Still, it prevented a record from occurring when the ice was well beyond record lows in May.

[bluewave]

1 hour ago, ORH_wxman said:

 

 

Looks like it was displaced a bit too much toward the Asian side though to produce the type of cold we saw in those other seasons. (1996 had the coldest June/July on record and 2013 was top 5) Still, it prevented a record from occurring when the ice was well beyond record lows in May.

It's as extreme a pattern reversal that you are going to see from the winter and spring record warmth to cooler summer. That PV was so strong

that the Pacific sector North of Alaska to near Siberia was actually colder than 2013 was.

 

 

 

[csnavywx]

Edit: Chubbs beat me to it. AMSR was -145 and shadow CT was -170 yesterday.

[Sophisticated Skeptic]

just because of an ordinary weather bomb, or in-combination with all the ice up there as well?   I don't remember seeing these earthquakes mentioned during the biggest of nor'easters.

https://www.yahoo.com/news/japan-scientists-detect-rare-deep-earth-tremor-200327022.html

Japan scientists detect rare, deep-Earth tremor

Miami (AFP) - Scientists who study earthquakes in Japan said Thursday they have detected a rare deep-Earth tremor for the first time and traced its location to a distant and powerful storm.

The findings, published in the US journal Science, could help experts learn more about the Earth's inner structure and improve detection of earthquakes and oceanic storms.

The storm in the North Atlantic was known as a "weather bomb," a small but potent storm that gains punch as pressure quickly mounts.

Groups of waves sloshed and pounded the ocean floor during the storm, which struck between Greenland and Iceland.

Using seismic equipment on land and on the seafloor that usually detects the Earth's crust crumbling during earthquakes, researchers found something they had not detected before -- a tremor known as an S wave microseism.

Microseisms are very faint tremors.

Another kind of tremor, known as P waves, or primary wave microseisms, can be detected during major hurricanes.

P waves are fast-moving, and animals can often sense them just before an earthquake hits.

The elusive S waves, or secondary waves, are slower, and move only through rock, not liquid. Humans feel them during earthquakes.

Using more than 200 stations operated by the National Research Institute for Earth Science and Disaster Prevention in Japan's Chugoku district, researchers Kiwamu Nishida and Ryota Takagi "successfully detected not only P wave microseisms triggered by a severe and distant North Atlantic storm, known as a weather bomb, but also S wave microseisms, too," said the study.

"The discovery marks the first time scientists have observed... an S wave microseism."

Microseism S waves are so faint that they occur in the 0.05 to 0.5 Hz frequency range.

The study in the journal Science details how researchers traced the direction and distance to the waves' origins, and the paths they traveled.

The discovery "gives seismologists a new tool with which to study Earth's deeper structure," said Peter Gerstoft and Peter Bromirski of the University of California, San Diego in an accompanying Perspective article.

Learning more about microseismic S waves may "add to our understanding of the deeper crust and upper mantle structure."