csnavywx

On 6/3/2017 at 6:34 AM, chubbs said:

Wipneus' daily sea ice volume anomaly chart updated through May. The volume gap between 2017 and other years narrowed in May due to a relatively slow start to the melting season vs recent years. Melting accelerated though in the second half of May leaving a record low well within reach this year depending on the weather.

Still a pretty decent gap there. Upcoming D3-D5 pattern look conducive to the development of widespread ponding pretty much basin-wide. Pretty similar to the 2012 pattern, just a couple of days later in the calendar, with the addition of the Atlantic side getting hit at the same time. Depending on how long that pattern lasts, we could see a pretty quick swan dive in area/extent/volume figures. The Pacific side is particularly weak and thin with FYI this year and it'll take less to demolish that ice cover than it typically does.

2012 cliff started in a few days. It looks like the forecast is pointing towards increasingly hostile conditions in the next week (recent model skill caveat applies here) which might give that 2012 dive a run for its money. 2017 is starting with less ice in the Chukchi, but more in the Kara and Barents. Preconditioning is somewhat less this year, but the ice is notably thinner due to warm winter weather. It'll be interesting to see how this plays out as we head into the most critical period for ponding.

Area tanking fast as melt ponding sets up. -157k yesterday and -117k. Now in 2nd place behind 2016. Kara/Barents look to be getting hit, with some contribution from the Beaufort and Hudson Bay.

Model skill scores are still in the tank and generally unreliable past D4 right now, but they do more or less show more widespread warmth continuing through the next 4 days. The EC is suffering less than the GFS is, but still taking significant hits to its scores.

Stable 5-wave pattern showing up on ensembles now for the first week of June. That leaves the door open to ridging over/near the pole but doesn't guarantee it.

The GFS and GEFS skill scores have been in the tank over the last week. Euro and EPS have suffered as well, but not as badly. Use with extra caution.

13 minutes ago, forkyfork said:

that is a pretty favorable melt pattern after day 7. we'll see if it's real

Yeah, EPS and GEFS are showing a pretty strong +AD pattern from D6 onwards. The CFSv2 has been barking on this for weeks and was for the current cold spell as well. It'll be interesting to see if that verifies as it would pretty much jump-start the melting season. Interestingly, looking back, the first 12 days or so of May 2012 were pretty cool as well before it flipped warm.

Volume topped out at 20.7K km3. Terrible. Currently, there is a 1.6K gap with 2011, the previous lowest record. Near to slightly below average temps will help close a bit of that over the next 7-10 days. After that, signals are emerging for the massive NAO block to retrograde into a position to help produce a +DA by around the middle of the month and rapid warming over most of the basin. The GEFS, EPS and CFSv2 weeklies are on board for it atm, so this will have to be watched. A +DA going into the later half of this month would be bad news, as the Beaufort and Chukchi Seas won't offer up much resistance with a near total lack of MYI this year.

DMI 80N temps finally fell to normal for the first time since last summer. CFSv2 weeklies showed this happening a while back (starting at least in early/mid-April). The next couple of weeks look fairly cool compared to what we've had recently (wrt normal). W3/W4 shows some action -- so we'll see if that pans out as we're coming upon the critical period for early season melt ponds in about 3-4 weeks.

High eastern Pacific SSTs tend to favor melt over the Pacific and parts of the CAA, so keep an eye on that. Of course, a good PV pattern over the pole could negate a good deal of the potential damage. The Beaufort/Chukchi and Kara/Barents regions are particularly vulnerable this season due to low in-situ starting thicknesses. The Chukchi in particular didn't freeze over until early January.

A couple of sharp drops on JAXA over the past couple of days (-98k and -112k) as the peripheral seas are getting hit with some pretty high temps for this time of year. Some outright melting conditions are present over the Kara/Barents Sea area as well and look to continue for the next few days, so we may have hit our maximum for the year on extent. FDD anomaly totals are piling up again after a brief pause late in Feb and early this month.

IJIS extent in Antarctica is down to 2.25M, now at lowest on record with a 1-2 weeks to go on the melting season. NSIDC not far behind.

Arctic extent up just 47k over the last 5 days. That may change after we get some cooler weather in a few days. Might even get a week of normal temps/climo weather in that region before that Pac jet extension and upcoming secondary SSW conspire to buckle the Pacific pattern again and likely build another AK/Pac side ridge.

Yeah, extent is fairly insensitive to basin-wide temp at this time of the year and is much more subject to temp swings on the edges (over the Bering, Ohktosk, Kara, Barents, etc). Much too early to make any calls there.

Volume and very high basin temps are the big story of the refreeze season.

5 hours ago, Jack Frost said:

For starters, refute or cite to a paper or papers that refutes the following:  http://edberry.com/blog/ed-berry/why-our-co2-emissions-do-not-increase-atmosphere-co2/

Please provide the cv(s) of the author(s) so that we can all assess credibility.

Thanks. 

I'm more than willing to engage at length on this, but this phrasing leaves room for backsliding or goalpost-moving later. It also implies you have other objections besides the issue you raise. I want an intellectually honest conversation where there is no chance to drag the conversation through the weeds or possibility of engagement in an obstacle-course style argument where an endless stream of objections is thrown up after the first is countered. Basically, I'm trying to provoke you to think honestly about your position and set a standard that can be falsified*. Please provide the a full accounting of what it would take to convince you that it is human-caused climate change. The reason is that I want to know ahead of time if it's even possible to change your mind on the issue. If your personal standard is, for instance, too high (e.g. Earth must become Venus-like), then obviously no amount of data or argument will meet it and I've wasted my time.

*Holding a scientifically-sound position means it includes the possibility of being falsified if a defined set of conditions are met. If it can't, it's speculative, hypothetical and/or faith-based and I'm not here to engage in that line of conversation.

Answering the question I pose above (in a way), this year is already considerably worse than any other in the basin with the slight exception of 2013, which also had a weak Pacific, though not quite as bad as this year. It's a bit deceiving though, as 2013 turned colder after the first few weeks and went very cold in February, something this year isn't likely to do -- so this likely opens up a wide gap even with that year. The volume differences outside the basin appear fairly minimal at this point (when comparing the actual thickness graphs) when compared to that year, so there's every reason to believe a 2009/2013 style summer won't be able to put up the numbers we saw in those years. If we continue with the ridiculous warmth for another 6 weeks, the ship will have likely sailed.

It's a bit ironic, since fast FYI growth in a near MYI-less landscape was the last big buffer left to prevent a quick transition to a near-sea ice free state and this winter seems poised to largely erase that buffer. The Arctic is great at making fools out of prognosticators, so I'm not quite ready to throw my hat all-in on a new record, but I feel it's pretty safe to say that the chances have increased significantly at this point. A tie in volume with 2007 last year after a below-average summer increases confidence a bit too.

18 hours ago, chubbs said:

Wipneus has updated PIOMASS sea ice volume for January. As expected, ice volume growth continued to lag in January increasing the shortfall vs. 2012 and 2013. In January, 2017 had roughly the same volume growth as last year, maintaining a  roughly 2.3 1000 km^3 gap. If 2017 continues to have volume growth rates similar to 2016, then the volume peak this year should be somewhere around 20,000 km^3 in April.

20K km^3 with a record small loss would still result in a minimum just below last year. A well below average loss of 17k (2013-style) would put it below 2012 volume. That's ballpark, though, and I'd like to get a comparison of basin-only volume losses (minus the peripheral areas like the Ohktosk, Bering, Hudson and St. Lawrence as they melt every year and starting below average in those areas doesn't mean much). Regardless, it's easy to see how a new record becomes much more likely with such low maximum volume.

2 hours ago, Jack Frost said:

I do enjoy this thread because it is empirical.

However, yawn.  To the extent that the extent of arctic sea ice moves in one direction or the other, the tie to Global Warming / Climate Change is tenuous at best non-existent.  Has anyone checked out the latest survey of underwater sources releasing geolocked carbon?  The AO?  PDO?

Much more interested in the relative humidity in the stratosphere and the direct relationship to increases in C02.  Just sayin....

Out of curiosity, what evidence would you have to see to convince you that it is mainly climate change? What standard would it have to meet?

Feb 1st update:

Conditions continue to deteriorate vs other years. The longer range forecasts for the first 2 weeks of Feb. look terrible for almost the entire basin. Some improvement is forecast for the Bering Sea and Beaufort areas next week, meaning extent numbers are likely to climb back towards the pack:

Volume gains will continue to be slow. We're on track for a -1700 to -1900 FDD freezing season (using 80N+ temps as baseline), far below any previous winter. With 2 weeks of hostile re-freeze conditions forecast, only about a month remains for significant volume gains heading into the melt season.

Despite the one decent cold spell over on the Pacific side, the ice there is still quite thin:

Time is running low for the peripheral seas. Without a recovery soon, these areas aren't likely to survive very long during the melting season without a 2009/2013 style summer. A below average (2016-like) June isn't going to cut it. With the sun returning in a few short weeks, any remaining open water likely will not freeze and will start absorbing insolation earlier than at any time seen in recent history.

In other news -- Antarctic sea ice extent is down to 2.51M on NSIDC, lowest on record for the date and 7th place against the all-time minimum of 2.26M set on 2/27/97.

Area at 1.87M vs mins of 1.24M in 1993 and 1.50 in 1984.

Very cold conditions over the Bering and Okhotsk have allowed extent to catch up and pass 2006, offsetting losses on the Atlantic side. The Pacific side should warm up over the next two days and put a halt to any further advances there, but we should finally see a relaxation of the very warm conditions near the pole for a bit.

Stall speed again on extent. No net increase over the last 9 days. Will probably remain at/near the level it is now for another week with the upcoming warmth and storms as the Atlantic side is chewed up again for the umpteenth time this winter.

Another ice destroyer being modeled on the Atlantic side in a few days. Hits the Kara/Barents pretty hard, but pulls warm air all the way across the pole too. Might turbocharge Fram export depending on the track (a la recent runs of the Euro). At least the Chukchi gets a break from the relentless blowtorching.

Thanks for those links. Interesting results.

Trick now will be pinpointing which mechanisms are most important and/or which are providing synergistic interactions or feedbacks. I have a feeling the Blue Ocean experiment was on to something, but we'll see with time.

That's pretty much how I envision getting the first near ice-free September day. Combine a winter like this one (with a finish below 3500) and a summer like 2007 and you're pretty much there. Maybe not quite -- but it's pretty close. That extra 30-40cm of missing ice growth on the edges will make all the difference in the world in getting the outer periphery to melt very early on, as in 2-3 weeks earlier. That puts the CAB under the gun in July rather than August -- with a higher sun angle and a longer period of time to heat the peripheral seas.

Of course, it's going take a whopper of a summer to get this to happen this early, but in 10-15 years -- not so much. It seems the ability to get a warm enough winter to stifle ice growth enough to put away all of the ice in a single summer is close to being in reach. That was a topic of discussion on this board last year. I just didn't think we'd be seeing a winter this warm so early.

My main concern this year will be the Chukchi/Beaufort and Barents/Kara area. Ice in those areas is (very) abnormally thin and likely won't make it past ~80-100cm before spring. The fact that it took until the first week of January for the Chukchi to finally finish freezing over isn't a great sign. One bad weather spell in May/June will quickly erode what used to be a bulwark for the CAB. Gotta hope for a 2013 or 2014 style summer to get out of this one.

We have probably at least 6 weeks as Don alluded to. The sun has to return to the peripheral seas before max can be attained. Getting it in mid-January is nearly impossible as heat lag hasn't finished cycling off of the solstice.