ASI 2012 update 8: it shouldn't, but it does

During the melting season I'm writing (bi-)weekly updates on the current situation with regards to Arctic sea ice (ASI). Central to these updates are the daily IJIS sea ice extent (SIE) and Cryosphere Today sea ice area (SIA) numbers, which I compare to data from the 2005-2011 period (NSIDC has a good explanation of sea ice extent and area in their FAQ). I also look at other things like regional sea ice area, compactness, temperature and weather forecasts, anything that can be of particular interest.

Check out the Arctic Sea Ice Graphs website for
daily updated graphs, maps and live webcam images.

ATTENTION: There are still 3 days left to vote on the polls in the right hand bar.
One is for Cryosphere Today minimum daily sea ice area, the other for NSIDC minimum monthly sea ice extent (the one that is used for the SEARCH SIO projections). More info in this blog post.

July 28th 2012

I'm basically going to say the same thing as I did in the last ASI update: Weather patterns haven't been conducive to sea ice decrease, trend lines on graphs should be stalling, but they don't. As I've shown in yesterday's blog post comparing this year's weather patterns in June and July with previous record years, the decrease should have slowed down significantly like it did in 2010 and 2011, but it didn't. The 2012 SIE trend line shouldn't follow 2007 so closely, but it does. The 2012 SIA trend line shouldn't lead, but it does.

Now air and sea surface temperatures are higher than in previous years, but does that explain all of it? Personally, I don't think so. I think ice thickness is playing a big part in all of this. One of the conclusions I found most important last year, was that, yes, the weather is still dominant and determines whether a melting season will see a new minimum record or not, but only as much as ice thickness will allow it. There comes a point when large parts of the ice pack become so thin that it doesn't matter what the weather does. Sure, ideal conditions will cause a nosedive, but the train keeps chugging along, even when the weather isn't so great for melt, transport and compaction.

I believed I saw that in September 2011. I believe I'm seeing it now too,
4-6 weeks earlier. Maybe my eyes deceive me.

Sea Ice Extent (SIE)

In the last ASI update I was wondering whether the 2012 trend line
on the IJIS SIE graph would veer off to the right towards big staller 2010:

But it didn't. Especially in the last couple of days the 2012 trend line has decided to track new leader 2007, after following 2011, which had a brake put on its decline in mid-July. 2007 had a very strong first week in August, so it will be interesting to see whether 2012 can keep up or not.

The current difference between 2012 and other years (without the unrealistic last data point that gets revised upwards) is as follows:

• 2005: -593K (-83,709)
• 2006: -608K (-70,025)
• 2007: +198K (-98,608)
• 2008: -683K (-81,260)
• 2009: -371K (-92,127)
• 2010: -376K (-62,601)
• 2011:  +90K (-83,473)

Between brackets is the average daily SIE decrease for the month of July. 2012's average daily SIE decrease for July currently is -87,101 km2 per day, which is quite a bit less than 10 days ago, but given the circumstances quite high. One would have expected it be more like 2010's average of -63K, but it's actually third highest.

Sea Ice Area (SIA)

Despite a couple of slow days in the past week, the situation on the Cryosphere Today SIA graph is basically the same:

Here we see the difference between area and extent at work. The slowdowns in 2010 and 2011 are less apparent here because of melt ponds and holes within the ice pack. This year there are a lot of holes on the Pacific side of the Arctic, these get counted for SIA, and so the 2012 trend line is still leading, and has been for almost a month now. Despite today's uptick I think 2012 will stay in the lead until the end of the month.

As we saw in this blog post, the CT SIA anomaly graph broke through the 2 million km2 barrier earlier than ever this year. It has shot back to 1.8 million, but given the fact that the long-term average decline is going to slow down, I wouldn't be surprised if it dips below 2 million some more before the period of re-freeze:

The current difference between 2012 and the other years is as follows:

• 2005: -857K (-76,120)
• 2006: -939K (-77,397)
• 2007: -218K (-91,629)
• 2008: -797K (-89,552)
• 2009: -867K (-99,165)
• 2010: -465K (-73,502)
• 2011: -111K (-91,469)

Between brackets is the average daily area decrease for the month of July. 2012's average daily area decrease for July is currently -86,335 square km per day. That's a big drop compared to two weeks ago (-105K), but still a lot higher than 2010, the year that also had anti-melt weather patterns in July.

Cryosphere Today area per IJIS extent (CAPIE)

CAPIE has been low, supporting the satellite images showing holes in the ice pack. These holes get counted for sea ice area, but not for sea ice extent, so if you divide the one by the other, you get a CAPIE or compactness percentage that tells you something about how patchy or Swiss-cheesy the ice pack is compared to previous years. Here's the graph:

With extent going down a bit faster in the last couple of days, and area going slower, CAPIE has gone up a bit again, but it's still really, really low for the time of year.

Percentages for July the 26th:

• 2005: 69.70%
• 2006: 71.04%
• 2007: 68.56%
• 2008: 68.64%
• 2009: 72.27%
• 2010: 66.78%
• 2011: 66.09%
• 2012: 63.44%

Regional SIE and SIA

Regional graph of the week:
I'm guessing this graph will be Regional graph of the week in more updates to come, as this is one of the few regions left that still have ice in them, together with the East Siberian Sea, Canadian Archipelago and Greenland Sea (where there's always ice because of transport from the Arctic Basin). In fact, the Arctic Basin is the biggest and most important region of all. This is where we expect the last of the ice to be, by the time the Arctic is coming close to becoming ice-free.

The trend line on the Arctic Basin SIA graph has dipped below 3 million km2, a recurring feature since 2007. Judging by this MASIE extent graph it seems to be going down faster than other years, which is hardly surprising with those holes showing up all over the place:
Most of the regions on the Regional Graphs page are practically empty of ice. The nosedive I expected on the East Siberian Sea SIA graph came about, and the Canadian Archipelago (where a lot of ice is melting in place, instead of being transported to warmer waters) is going down hard as well.

Sea Level Pressure

As usual I start with an animation of SLP images from the Danish Meteorological Institute to see what has happened in the past two weeks:

The lows dominating the Arctic, churning up and diverging that ice for the first 10 days since the last ASI update, can clearly be seen. Much of the transport towards Fram Strait was cut off, but at the same time those lows didn't move over the Canadian Archipelago either, so these effects perhaps cancelled each other out. Towards the end of the animation we see a weak high taking over and then moving in the direction of Canada. Basically things are at a standstill right now, due to a lack of intensity of both high- and low-pressure systems.

Maybe the weather forecast by the the ECMWF forecast model can tell us whether the weather will stay like this:

I would say it does seem like it will stay like this. Highs remain dominant on the American side of the Arctic, lows on the Siberian side, but I don't see anything intense that either spurs or slows the decline. For a fast decrease you need a strong high in the 1025-1035 hPa range, preferably over the Beaufort Sea. Or a nice cyclone in the 985-995 hPa range to stir things up and cause some of that flash melting that we love so much on the ASI blog because it looks so awesome.

Actually, we have been seeing some flash melting already, without that cyclone, but more on that some other time.

Temperatures

A bit more yellow and green air temperature anomalies in Siberia, a bit less in Alaska, northern Canada and Greenland, compared to two weeks ago:
When it comes to sea surface temperature anomalies (as calculated by DMI), things look again much worse than the image I posted two weeks ago for the previous ASI update:

There's significantly more red in the Laptev Sea, the red in the Kara and Barentsz Seas grew and intensified some more, and it's growing in the Beaufort Sea as well. Luckily, it seems to have cooled down a bit in the Chuckchi Sea and Bering Strait.

I'm getting increasingly worried about this. 4-5 °C warmer than on average in so many parts of the Arctic. I wonder what that will bring come September and October. If it stays like this, of course.

Update conclusion

With ice that doesn't seem to care what the weather does and warm temperatures in many places above and below the ice, it's no wonder that SIE and SIA keep decreasing steadily. This melting season doesn't resemble 2007 in any way really, but 2012 is keeping up with the tempo easily. The longer the weather stays like this, the stronger the evidence becomes that the ice is thinner than it has been for a long, long time. If it doesn't stay like this and weather patterns start to move towards something that made 2007 so formidable, we will need a word that surpasses 'formidable'.

The weather is neither fish nor flesh right now, but the ice pack keeps getting smaller, from within and without. We will know more in two weeks.

Comments

[AmbiValent]

Is it really more formidable than 2007? 2012 might end up with less ice area and extent, but it already started with much less ice volume than 2007 did.

You might well say that 2007 cleared the way, and 2012 now has it much easier.

[Neven]

You have a point, AmbiValent. All I meant to say, is that when we get to see 2007 weather conditions for a prolonged period in August (ie a Dipole Anomaly) the melting will be at least as spectacular as in 2007.

If I have seen further it is by standing on ye sholders of Giants.

- Isaac Newton

[Tor Bejnar]

I know the discussion has happened in the past, but for clarity:

In the "Cryosphere Today area per IJIS extent (CAPIE)" section, Neven wrote "... These holes get counted for sea ice area, but not for sea ice extent …" The "holes get counted for sea ice area" means that the holes get counted as being water.

[Tor Bejnar]

Seke Rob,
I posted a reflection on one of your graphs at the end of "ASI 2012 update 7". I'd sure appreciate a hand in developing my ideas from somebody with more data manipulation and graphing skills.

[dabize]

The Sea Ice thread at AW has had a nice discussion of whether the factors driving extent and area loss are as dominated by local weather (vs emergent AGW effects) as they were in previous years.

http://www.americanwx.com/bb/index.php/topic/156-arctic-sea-ice-extent/page__st__5810#entry1670730

Neven's previous post on the rules driving recent SIE/SIA loss was discussed/dissected in this context as well.

FYI.........

[Paul Klemencic]

Neven, excellent update. I haven't been able to participate in the discussion here this year, due to time constraints, but I think you have reached the correct conclusions throughout your post.

Clearly something has changed dramatically in terms of ice pack loss.
Summarizing the excellent discussion on the some of the previous posts, there are three principle methods for moving thermal energy into the Arctic ice pack:

- Summer solar insolation (increasing because of changing albedo);

- Ocean currents, and currents moving water warmed by insolation in the various lower latitude seas of the Arctic (particularly the Beaufort, Laptev, Kara, and Barentsz seas) into the ice pack (or the ice pack shifting over the warmer waters);

- Heat transported through the atmosphere into the Arctic, with the sensible heat of the air volume not nearly as important as the moisture (humidity) carried by the air.

Someone on one of the previous posts estimated the amount of thermal energy added to the Arctic by increased albedo; it clearly is a huge amount of heat, and the extensive melt ponds and open polynyas should have increased the absorbed solar energy this year. But the weather conditions this year were not particularly conducive to substantially increased absorbed insolation.

Neven estimated the amount of thermal energy being carried into the Arctic by the ocean currents. The amount of heat is significant, but again the rate that thermal energy is carried into the Arctic Basin by the currents likely varies, but it is unlikely to account for the big changes this year. But the incursion of water heated by insolation, or weather systems, at lower latitudes into the ice pack must be a big factor in the ice pack loss.

Which leaves top melt caused by increased heat transport by the lower troposphere. In prior years, if a LP system moved over the Arctic, the north pole cams would show new fallen snow, even in July. This year, the cams showed mostly raindrops and puddles when the LP systems moved through. The lower troposphere in the Arctic is warmer, which is consistent with meteorological measurements.

Typically the early season is the top melt season, and starting around August 1, the bottom melt takes over. One indicator we should look for: the melt ponds should begin freezing over near the NP. This year, the top melt seems really bad, even with less than ideal conditions. The extensive areal melting of the Greenland ice sheet (even up to 3000 m) indicates that the lower troposphere is clearly warmer over the Arctic regions. This is a stunning result, just by itself. But the warmer troposphere evidence also shows some important issues about thermal energy teleconnection into the Arctic.

The key to maintaining a significant ice pack throughout the summer in the Arctic, is the stability of the ice pack over 80N. Getting heat into the far north is difficult. Normally, the air movement through the troposphere would lose most of its moisture (and transported latent heat) due to rainfall, and snowfall at lower latitudes. The air masses moving over the 80N Central Arctic would drop to freezing temperatures long before reaching the far northern latitudes.

This year, its raining all over the Central Arctic Basin (not to mention higher altitude Greenland). But if the regions near the NP are getting rain regularly, the amount of heat being transferred into the regions between 75N to 80N must be enormous.

Also, when the ice pack surface has extensive melting snow, ice, and melt ponds (not to mention polynyas), then the heat transfer between the air and the surface increases substantially. The heat transfer between the water (fluid) in the melt ponds (and polynyas) and air, is much higher than solid ice and air. Additionally, the water can entrain into the wind, warm, and fall back to the surface (check out the water droplets hitting the lenses on the ice cams).

Even worse, all of these heat transport mechanisms (increased absorbed insolation, higher temperature seawater contacting the ice, and increased heat transport by atmospheric moisture getting through into higher latitudes) reinforce each other with positive feedbacks.

Essentially, it takes a lot more refrigeration (ice melt) to cool moist warm air down to zero deg C, than dryer air at a similar temperature. And LP systems move more moist air into the Arctic Ocean, than HP systems.

I think this year, we have seen the Arctic basin go over a tipping point. From this year forward, the ice pack (and Greenland ice sheet) decline should accelerate. And one of these years, weather conditions will be more conducive to melt or heat transfer, and we will get a blowout year. It could still happen this year, which I will discuss in the next comment.

[Paul Klemencic]

Re-reading the last comment, I should have said "And LP systems move more moist air into the Arctic Ocean, than stationary HP systems."

If the guys who did the solar insolation calculations, and the ocean current calculations, could summarize the data on heat transport in the Arctic from these sources, it would be helpful. I would like to see how these quantities compare to annual Gulf Stream thermal transport.

[Paul Klemencic]

Ice pack melt mechanism

OK, we know more heat is getting into the Arctic. Getting heat into the Central Arctic Basin is still tough. If the ice pack loses it's lower latitude extent early enough in the season, the central pack can be fractured and pushed out by wind and current.

There appears to be enough thermal energy to eliminate the lower latitude ice pack. But the thermal energy must transfer into the ice fast enough to accomplish the melting of these lower latitude regions within the next month.

Last year, I estimated the heat transfer rate to get both the top melt rate, and the bottom melt rate, measured by the buoys. And I estimated that the heat transfer rate needed to rapidly (overnite) melt off the fractured pack floes at about 100x the normal heat transfer rates. For this reason, I was skeptical about the massive flash melts we saw last year in the Beaufort and Chukchi regions.

But the evidence was very strong, that at some point the ice pack is fractured enough, and has enough ice surface area in contact with warmer replenished seawater, to hit the higher heat transfer rates.

This last week we saw this again. Flash melt in the Beaufort, Laptev, and E. Siberian regions were significant. And the weather systems that caused these events was not nearly as strong as last year's strong cyclonic LP systems.

Clearly, at some point the ice pack is thin enough, and fractured enough, for the heat transfer rates to climb as much as two orders of magnitude (exceeding 100 cm per day) compared to stationary pack melt of 1-2 cm per day.

I think the Laptev is still the weakest route to the CAB and NP, but this year, the E. Siberian region off the New Siberian islands, is weakening fast enough to combine with the "Laptev bite" to really eat into the deep CAB over 80N.

Open water at the NP is still a long shot this year, but CAB MASIE extent falling below 2.0 million sq km is likely. That should result in the Arctic extent dropping below the 2007 level at the minimum.

[Seke Rob]

Had not looked hard the last week, but quite surprised to see the Greenland Sea being currently so much short on ice... -127KKm^2... transport stagnation in Fram or flat flash melt as mentioned? See http://bit.ly/MASIEA for picture, tabulation and comparison to last year for July 27

[dingojoe]

It is a rather small corner, but the fast ice along the NE Greenland coast looks like it's ready to completely fracture. It doesn't always do this and when it does, it tends to be much later and the ice doesn't clear out or melt before refreezing sets in. This year could be different.

http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?subset=Arctic_r02c03.2012210.terra.250m

[R. Gates]

AmbiValent said:

"You might well say that 2007 cleared the way, and 2012 now has it much easier."

_____

2007 was the tipping point year and did set the stage for those that followed, and of course there were black-years in the several prior to 2007. But if you look at this anomaly graph for the Arctic basin, and imagine it is the pulse of a patient in the hospital, you can see quite easily that the pulse changed in 2007 in a dramatic way (with a precursor shock in 2006 before that summer turned colder):

http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/recent365.anom.region.1.html

This range of 2+ million below "normal" sea ice area is now the new normal, and I'm waiting for the first 3+ million below normal period (Sept.-Oct. of this year could be possible)

[Neven]

transport stagnation in Fram or flat flash melt as mentioned

I think the first, Rob. Lows dominating the Arctic kill the Beaufort Gyre and Transpolar Drift Stream, and those two are needed for transport through Fram.

This last week we saw this again. Flash melt in the Beaufort, Laptev, and E. Siberian regions were significant. And the weather systems that caused these events was not nearly as strong as last year's strong cyclonic LP systems.

That echoes my conclusion, Paul. Thanks for your analysis, interesting as always.

[Bob Wallace]

The ARC is predicting movement of some of the thickest ice into the Beaufort over the next few days.

At the same time 2 meter thick and thinner ice should continue to move outward through the Fram. That should open things up for more thicker ice to be transported out when thick ice direction reverses.

[crandles]

The area loss in the last week at only 50k per day is the second lowest year for area loss at this time of year. Only 1995 had less.

The weather patterns certainly haven't been ideal for area decline, but have they been that good for keeping area high? Particularly with water temps as they are.

Is it possible that area isn't declining as fast as expected because the ice has been breaking up so much and is therefore getting the opportunity to spread into a thinner layer?

Perhaps that is unreasonably alarmist? You can certainly argue I cherrypicked this particular week because of the rise in the last days data causing this week to look unusually low for area decline.

[toby]

Are we seeing more "century breaks (>100,000 km^2)" this year than ever before (on JAXA, at least)?

The "ups and downs" of this year look qualitively different than other years. There seem to be more large daily melts, and more smaller ones as well.

Or is that just a new satellite, or a policy shift by the scientists?

[Neven]

Toby, it's definitely due to the switch from high-resolution AMSR-E to low-resolution WindSat.

IJIS SIE has had 35 century breaks so far this melting season. Record holder 2007 had 16 so far and would end at 20.

CT SIA centuries are more consistent in this respect, and I will soon do a post on that, out of tradition and respect for the noble sport of snooker. ;-)

[Twemoran]

Paul

Everything you said

PLUS

Ekman pumping, which had very little effect on thicker, more compact ice. Even a weak low is leaving behind a trail of widely dispersed ice sitting in a warm brine dredged from the depths.

Terry

[SteveMDFP]

Paul Klemencic

Thanks so much for your contributions here. I think you've presented an excellent synthesis--pulling together disparate mechanisms and findings that individually result from analysis of data.

It seems to me that the only way sea ice could fail to fall below all-time records is if arctic weather remains ideal for ice preservation -- weak, diffuse low pressure with clouds and mild winds. Any deviation from this (intense lows, significant highs, any strong winds in any direction at all) will drive the thin, fractured, vulnerable ice to melt.

[George Phillies]

July 28 From the Bremen images, there seems to be a drastic change in the last couple of days in the area from the Bering straits and East Siberia up to about 80 N; lots of melting and opening seems to be happening.

[Neven]

We have been discussing some of that here earlier today, George. I'm expecting some of those holes to fill up again, because the drastic change is, I think, partially explained by ice not being picked up by sensors. But we should all keep a close eye on this because it's very early in the season for flash melting.

[Espen Olsen]

"transport stagnation in Fram or flat flash melt as mentioned"

I believe the Fram transport system pace is very reduced pt. the web cams # 1 -2 at the "pole" are parked at 84.145 and did only move very little over the last 2 weeks.

[Seke Rob]

Don't know which map you're looking, the one I follow is this http://psc.apl.washington.edu/northpole/DriftTrackMap.html which has not been updated since the 16th, so yes this map is parked.

[Espen Olsen]

Seke Rob : http://psc.apl.washington.edu/northpole/

[Seke Rob]

Thx... 1 step up in the link. Barely half a degree in 12 days.

[SteveMDFP]

Seke Rob,

I've noticed that when transport out the Fram Strait is brisk, almost all the polar ice moves in that direction, judging by motion of the drift buoys--their trajectories are roughly parallel to each other.

This drift map separates the last 10 days of motion from the rest of a 60-day track. Yes, the past week or so has seen a big drop in transport out the Fram. If/when the weather again favors transport out the Fram, the more mobile ice may now move more quickly. See:
http://iabp.apl.washington.edu/maps_daily_northpole.html

[dorlomin]

The Bremen map looks like we could be in for a few days of big drops, its full of big big gaps in the ice near the Bearing Strait.

[Bob Wallace]

Bremen is also showing a lot of blue in the NWP.

[Chris Biscan]

The GFS is brutal.

tons of compaction and heat.

[Rob Dekker]

As for export through Fram straight, Obuoy4 is about to enter Fram straight any day now (currently at 82N - 9W).
http://obuoy.datatransport.org/monitor#buoy4/gps
It's been moving at a rather unremarkable 0.2-0.5 m/sec speed over the past week or so, although it has been speeding up over the past month, strongly guided by the winds, which seem to alternate between westerly (speeding up) and easterly (slowing it down).
Taken overall, there does not seem to be much "unusual" ice export into Fram over the past month.
So any significant ice reduction in the Greenland sea is probably due to melting and ice movements away (or towards) the coast line.

[Chris Reynolds]

I've nailed my colours to the mast and contrary to my usual conservative stance....

I think we're in for another record.

Details here - but the regulars won't find this news:
http://dosbat.blogspot.co.uk/2012/07/here-we-go-again.html

[AmbiValent]

Now ice seems to be breaking up in the northern Archipelago (north of Parry Channel). Ice also seems darker there to me in the arctic.io picture, but that might be to almost transparent clouds.

[Pete Williamson]

Following on from AmbiValents thoughts maybe it would be useful to look at the volume of ice that has melted or been export each year.

I'll contribute some rounded off numbers from eyeballing Wipneus' POIMAS graphs.

https://sites.google.com/site/arctischepinguin/home/piomas

All numbers are in 1000 km cubed of ice lost

Max (apr) to now (Jul)

2012 11
2011 10
2010 11
2009 9
2008 8
2007 8.5
2006 7
2005 7.5
2004 6
2003 7
2002 7

Max (apr) to Min (sept)

2012 ??
2011 18
2010 19
2009 18
2008 18
2007 17.5
2006 16
2005 17
2004 16
2003 17
2002 16.5

The volume lost each year is increasing but no obvious sudden increase in loss in any one particular year. Maybe somebody can provide the accurate numbers.

[Seke Rob]

With a little lack of luck, we'll be seeing CT dropping below 4MKm^2 before August 1 and July ending as showing lower than any year prior to 2007. Needs -300KKm^2 for July 27-31, where July 26 lost 69K.

Per current http://bit.ly/CTNHMn there are now 21 years of satellite observed record that had their annual 1 day minimum passed on or before day 209 of the year.

[dabize]

Rob,

Something to chew on.....

Looks to me from your figure that the low minimum areas seen 2007 and after are correlated with a distinct reduction in variance vs earlier years with respect to the date the minimum is set (SSS caveat, of course!)

Of course this might well be coincidental, but might it also reflect a simplification of the factors affecting the minimum date - such as the removal of significant levels of MY ice from the equation?

[Espen Olsen]

Jøkelbugt North East Greenland:

The big action these hours is happening in front of the giant glaciers Zachariae and 79 Fjords Glacier, the pack of ice in the bay is now in the process of departing from the scene, and it will be interesting to watch if the the Giant 79th will do her her move or if she is to shy to make a real move ,it looks like some pressure is mounting in front of her, so guys be prepared!

[Chris Reynolds]

Pete Williamson,

Using CT's area index

...............2007...2008...2009...2010...2011...2012
Max -> Min.....10.40, 10.89, 10.43, 10.74, 10.24 , 9.41

Max -> 27 Jul.. 8.73 , 8.73 , 8.62 , 8.98 , 8.67 , 9.34

27 Jul -> Min.. 1.67 , 2.16 , 1.81 , 1.76 , 1.57 , 1.79*

The final figure for 2012, Jul to minimum, is the average of the other figures for that period. I'm assuming here that there isn't an underlying physical reason for this
, in that I could be wrong. It is notable that from CT's timeseries of area, both 2007 and 2011 flatline around the minimum. This might just be coincidence. But it could be that as the melt gets closer to the pole, insolation is reduced and polar ice protected from loss. If that is the case we could indeed have to wait till next decade or later to see a near total loss of ice during the melt season.

However assuming that the issue above and the apparent downtrend in loss between 27/7/08 and 12 is not due to an underlying physical reason....

If we take the figure of 1.79 as a typical loss for this season then that implies a minimum this year of 2.57M km^2.

I can't do the same calculation for Volume because we've not yet got the volume data for that date. However volume shows the same decrease of loss during the Summer as does area, again, this year should make it more clear whether this is a new behaviour we need to understand, or whether this was just coincidence. Given the impact of 2007 if volume/area loss from 27/7/12 are lower than in 2011 a new trend must be suspected. At present I can't think of a reason for such a reduction.

[Chris Reynolds]

PS - to examine export you'd have to look at ice movement in the PIOMAS model, otherwise it's impossible to discern whether ice has melted in-situ or been transported out.

[Account Deleted]

It is surprising that on the official grafics in 2012 continues to go on a par with 2007.

http://nsidc.org/data/seaice_index/images/daily_images/N_stddev_timeseries.png

These data are more reliable than the IJIS data.
http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm
•Jan. 1980 - Jul. 1987 SMMR
•Jul. 1987 - Jun 2002 SSM/I
•Jun. 2002 - Oct. 2011 AMSR-E
•Oct. 2011 - the present WindSat

[Pete Williamson]

Chris,

The same effect occurs using my eyeballed volume numbers.
In 2011 ice volume lost in the second half of the season is 8000km3 (18-10).
While in 2003 the second half of the season lost 10,000km3 (17-7).

Whatever mechanism is responsible for the larger ice melt in the first half of the year is being moderated later in the melt season or on the more central ice. Something of a brake on runaway positive feedbacks possibly?

[AmbiValent]

Pete,
I would guess the ice in 2003 that melted was further outward that the one in 2011.

[Nightvid Cole]

I *really* miss the PIOMAS animation of the forecast ice thickness through the rest of the melting season...

[crandles]

>"I *really* miss the PIOMAS animation of the forecast ice thickness through the rest of the melting season..."

Oh, it is up now:

http://psc.apl.washington.edu/zhang/IDAO/seasonal_outlook.html

4.3 +/- 0.3

[AmbiValent]

How do they project it at 4.3 when Wipneus' projection says it's about 3.0, and the ice volume declared by Piomas for July 1 was below the projection for that time?!

[maltose]

Hi AmbiValent,

The 4.3 +/- 0.3 is an estimation of Sept. extent, not volume.

[AmbiValent]

Oops, my bad, the 4.3 prediction was about extent. But looking at the forecast, I think the +/- value is too low... there is a great amount of very thin ice, which may spread out at the right amout, showing great extent, or contracting, showing small extent, or spreading out too far, no longer getting shown as extent...

[maltose]

They seem to project that a lot of high-latitude ice on the Russian side will melt completely in August. How did they do in 2011?

[crandles]

>"How did they do in 2011?"

8 June 4.1+/-.6 (data to 31 May)
13 July 4.3+/-.5 (data to 30 June)
15 Aug 4.6+/-.6 (data to 31 July)

Actual 4.6

[Kris]

Precipitation records at Nome and around the Bering and Chucksi Seas:

... Nome breaks 101 year old precipitation mark...

For the second time in four days Nome has broken a long standing
precipitation mark. On July 28 Nome received 1.13 inches of rain
thereby shattering the old mark of 0.87 inches set in 1911. Our 5 day
total since this rain event began on Tuesday is a whopping 3.89
inches and it is still raining.

[Kris]

On top of the former, record precipitation as Kotzebue, Alaska too.

Kotzebue breaks 31 year old precipitation mark...

And as cherry at the cake, a "heat wave" at Alaska's Artic coast, spanning from Barrow to the Canadian border and beyond...

The North Slope was one of the warmest areas in the state today...

[Seke Rob]

Something is weird about precipitation this period. Japan had 100mm/hour rain events/750mm in 10 hours. Netherlands-South, had 65mm/0.5hours, and here while away we heard of flash rain, the trails of soil and pebbles on the road spoke for that. Our hill was absolutely soaked, when 5 km south/east nothing at came down... at least 2 months that accumulated 0.0mm.

Meantime, JAXA did not quite produce a century for the 29th, but prelim-prelim is -151K suggesting at least 1 is coming for the 30th. DMI nosedived on the 30% concentration metric, and 1 day behind on JAXA and MASIE: http://bit.ly/MASDMI

As for JAXA million stepping stone measure, who anticipates the descend below 6 million will not be quicker than 2011 [or 2010 for that matter]. 6 days in and already half way at 6.5M, last year and year before 19 and 15 days respectively. Think the true grid of 2012 is about to show. http://bit.ly/IJISMD

CT not out yet as at this writing. The global path is strange, not following the quasi regular profile: http://bit.ly/CTGB01 and Arctic only http://bit.ly/CTAR01

[as for Watts/Muller head bang], think the former made a humongous own goal [treads his own flaky standards once more]... moved the goal posts and forgot about the beam above :O]

[Seke Rob]

CT in, with 3 days of a constant anomaly, a smallish 62K reduction in actuals:

25-Jul-2012 208 2012,5671 -1,8230635 4,3680320 6,1910954
26-Jul-2012 209 2012,5698 -1,8235836 4,2991047 6,1226883
27-Jul-2012 210 2012,5726 -1,8290802 4,2368927 6,0659728

[Neven]

Thanks for the info, Kris!

[Nightvid Cole]

How is it possible for IJIS to have a value for today's extent when the map is black (no data) over the entire Arctic Ocean?

[Nightvid Cole]

Today's MODIS image seems to show that the western outlet of McClure Strait of the NWP is still completely blocked off - a non-icebreaker is not able to exit to the Beaufort Sea at this point...

[Espen Olsen]

Hi Nightvid Cole

If you are going by Kayak, turn left just before the last block ( Bank Island) down Prince of Wales Strait and you will find Beaufort Sea!

[Greg Wellman]

Espen,

Not just by kayak. I believe a guy named Henry Larsen made that same left turn in 1944 :-)

[Espen Olsen]

Not surprised same national background;-)

[idunno]

Has anybody mentioned that NSIDC has a new (week-old) analysis out?

http://nsidc.org/arcticseaicenews/2012/07/sea-ice-continues-to-track-at-low-levels/

[Neven]

Uni Bremen has put up extent charts again (scroll down). Hopefully Larry can get the exact numbers again and keep us up-to-date.

[Neven]

Big changes again on the UB SIC maps:

29th

vs

30th

CT SIA is looking more and more like a serious slowdown. The big changes on the UB SIC maps from a few days back didn't translate into big SIA losses after all.

[Jim_pettit]

Neven wrote: CT SIA is looking more and more like a serious slowdown. The big changes on the UB SIC maps from a few days back didn't translate into big SIA losses after all.

Indeed. Over the past ten days, SIA has decreased by only 484k. By comparison, the same ten-day span last year saw a drop of 780k (while 2007 fell by 745k during the same period). After being ahead of 2011 by more than a half million km2 just 12 days ago, 2012's lead has dissipated to a mere 68k.

Rank-wise, 2012 still holds first place, as it has for 47 of the last 52 days, and the last 31 straight. But that's in jeopardy; an increase today, or a decrease of fewer than 35k, will see 2012 fall back to at least 3rd place (behind 2011 and 2007).

Historical minimum day is statistically about six weeks away. Area needs to drop by a further 1,331,128 km2 to set a new record.

[Seke Rob]

Something of a variation on the chart that shows current CT SIA against prior year 1 day minima and a bar easing the discern of which years have *already* been passed [red segments]. http://bit.ly/CTNHMn . Of the satellite record, the last little reduction was enough to put the years that were higher at 67% [two-third], and it's "only" July 28 in data terms. The bar labels at top indicate by how much the red [stacked] bar years were higher than last data point.

[Seke Rob]

On SIA stagnation, the butcher in Dads Army always advised Mainwaring not to panic... MASIE slid another 81K http://bit.ly/MASIEA

[Kevin McKinney]

I think it was on this thread that I mentioned the Mann "Hockey Stick" review that I wrote... it's currently down. Will update when the situation is resolved. (And thanks to those who checked it out before this outage!)

[Chris Reynolds]

Seke, Great graphic "http://bit.ly/CTNHMn" really puts things into context.
Minor typo - More thAn now.

What package do you use to produce those graphics?

Anyone...

At present, through all the splatter, there is an underlying +ve index Arctic Dipole, general high pressure over CAA and Greenland, with low pressure over the Arctic Basin, this breaks down, but towards the end of the current ECWMF there's a neater +ve index dipole pattern forming.
http://www.wetterzentrale.de/topkarten/fsavnnh.html
select - 500hPa,Bodendruck (German for surface pressure)
We'll see...

Neven, Jim,
That area of low concentration is just getting more and more fragile. I expect something rather remarkable in the next 14 days. Have we ever seen a large chunk of ice seperated from the main pack this early in the season? I expect there to be a large remnant chunk off eastern Siberia with open ocean between it and the main pack. I still think we're in for another record.

[Chris Reynolds]

Before wrapping up for the night, here's what I mean about the difference 14 days can make.

16/7/12
http://www.iup.uni-bremen.de:8084/ssmisdata/asi_daygrid_swath/n6250/2012/jul/asi-SSMIS-n6250-20120730-v5_nic.png

30/7/12
http://www.iup.uni-bremen.de:8084/ssmisdata/asi_daygrid_swath/n6250/2012/jul/asi-SSMIS-n6250-20120730-v5_nic.png

[Pete Williamson]

It's early days but is it possible that the decrease in extent is beginning it's slowdown to the year minimum?

http://arctic.atmos.uiuc.edu/cryosphere/arctic.sea.ice.interactive.html

I think it's just spotting patterns and happenstance. It will likely accelerate again.

It would make for a truly weird season if it did though.

[Neven]

Holy crap, the NWP has opened up. That sneaky bastard!

I'll put a post up as soon as Terra is finished uploading.

[Bob Wallace]

Since I have a well-earned reputation for posting less than excellent questions and comments I feel I should take credit for introducing that possibility some weeks ago.

Sometimes even a blind pig finds an acorn....

[Llosmith57]

When comparing the Regional Graphs for July 30, Beaufort ice area per Cryosphere is about 50Km2 and NSIDC/MASIE shows 750Km2. This is well below the 15% saturation point for extent. Am I missing something? Chukchi and Laptev are just above the 15% cutoff point as well. If they drop below the 15% cutoff how long does adjustment to the extent normally take?

[Neven]

Post is up: Northwest Passage as good as open.

[Peter Ellis]

Lloyd: MASIE / CT use different boundaries for the various regions. Consider, for example, the winter values for the central basin. CT shows an area of 4 million, while MASIE shows extent of 3.25 million, for a total concentration of 123%...

[Bob Wallace]

ARCs is projecting almost no transport through the Fram over the next several days. Bremen is showing a lot of 50% concentration and open water along the northeast coast of Greenland.

Is there much chance for large melting and the creation of a lot of warmed water close to the CA if this holds?

[Kris]

What could be the black stripe visible at Obuoy 4?

[Seke Rob]

Chris Reynolds, all charts are done with Excel 2010 and some analysis add-ins to get good histogram/distribution graphics.

[Seke Rob]

Kris, looks like a shade from a pressure ridge. Angle of sunlight and exposure time gives these effects.

[Espen Olsen]

Kris,

I believe it is a stretch of open water?

[Chris Biscan]

http://i174.photobucket.com/albums/w109/frivolousz21/1343800364312505401932187.gif?t=1343812069

Beaufort is getting smoked.

huge sst's locally
very warm air and sun the next 3-4 days maybe longer.

This older ice might melt out with incredible melt rates.

you can see it turn from Grayish to blueish in 3 days and compact a ton.

[Neven]

Look at how close the holes are getting to the North Pole (bottom left).

[Seke Rob]

Sur place? Just in, CT -150K

2012.5753 -1.7730085 4.2358670 6.0088754
2012.5781 -1.8734319 4.0850444 5.9584761

[Seke Rob]

One day later and 79% of previous recorded years was higher: http://bit.ly/CTNHMn and 2012 veers away again from last year: http://bit.ly/CTAR01

[Espen Olsen]

Neven,

Those holes are within 400 kms from the Pole!

[Kevin McKinney]

A followup--if anyone had trouble accessing my Mann "Hockey Stick" book review, that's because it is down temporarily. Seems it was reposted in its entirety (without attribution!), and Hubpages has pulled it pending sorting things out...

Sorry for any inconvenience; I'll update when the original is available once again (as I expect it to be.)

Hey, at least I wrote something deemed worth stealing!

[idunno]

Hey veNen - you're in the Grauniad:

http://www.guardian.co.uk/environment/2012/aug/01/arctic-sea-ice-melting-2007-records?newsfeed=true

[Neven]

Great, do I get to meet George Monbiot? :-)

Nice to see that someone like Climate Central's Andrew Freedman drops in to read my ramblings. He writes very good stuff.

[dabize]

Hi Neven, I just emailed you a doctored version of this weeks MODIS composite, since I can never seem to resist doing that..........

I am in the "Beaufort is getting smoked" camp.

[Neven]

Here are the images dabize sent me:

Ice loss in the last month

Ice loss, one week vs one month

Great stuff, dabize, thanks for sharing. If things keep going like this, I feel a blog post coming up next week. Obviously.

[dabize]

Wow, fast turnaround, Neven!

As for my point, it looks as if Rob and Jim have already made it - area with a big jump down today.

I am curious about this month's PIOMAS volume number - those images really look as if volume loss is unusually high, even in the CAB.

[Seke Rob]

If Jimi Hendrix were still alive, he'd be singing "Where's" my purple haze?

http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=07&fd=30&fy=2007&sm=07&sd=30&sy=2012

Curious is the almost straight as an arrow demarcation of water/ice from Greenland to the Siberian coast. As of the day before, nothing left in Barentsz per MASIE and the linked CT image [well 18km^2 lurking in some inlet]... that did not happen in 2011 until Sept.20. MASIE BTW lost 113K from the 30th to the 31st.

[dabize]

Little inlets like the Gulf of Ob' are ice covered, but have SSTs of 10C.

Ice Nine?

[L. Hamilton]

Looks like many Manhattans of fast ice could cut loose from NE Greenland very soon.

http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?subset=Arctic_r02c03.2012214.terra.250m

[Espen Olsen]

Hi Larry,

Yes it is the most exciting area in the polar region in my view!

[Neven]

The Joekelbugt region is definitely spectacular, but how does it compare to previous years?

[Paul Klemencic]

Some comments on what kind of melt events we might see over the next few weeks:

1. The NP cams (now located around 84N) are beginning to show some ice refreeze at times. but also still show obvious moisture droplets. My interpretation is that its still raining instead of snowing at latitudes of 84N and likely higher. However the top melt should grind to a halt within a week, and the ponds should freeze over. However, as warm as it has been, the change on the surface of the remaining pack could be less than in previous years. The Arctic now has bigger bodies of water warmer than freezing surrounding the shattered pack edges. The melt rate will now be driven by the heat transfer from the water to the floes on the edges of the pack.

2. The Ice above 85N in the CABasin still hasn't shattered (except for the ice in the area of the "Laptev bite"), but the entire CABasin boundary is exposed to warmer seawater along the eastern side from 15N to 150N up to or above the 80N latitude. The ice between 80N and 85N is pretty well broken up, so the melt rate will be strongly determined by pack shifting movements over the warmer water, or storm driven wave action against the exposed floes.

3. As we observed last year, storms moving through the broken pack areas can eliminate large extent areas literally overnight, so keeping an eye on storm movement in August will be important. Current forecasts show significant LP cyclone in the Beaufort by this weekend, and moving throughout the Beaufort, Chukchi, and E. Siberian regions throughout next week. The low latitude ice less than 80N in these regions should be decimated next week. By August 10 at the latest, 2012 extent should be the lower compared to 2007 (even in spite of the big extent drops in 2007 over this timeframe), and from that point forward, 2012 extent will follow a new low extent trajectory.

4. The ice pack as whole is showing more mobility in blink comparisons of the Bremen graphs. Unfortunately, the Bremen maps have more variability (and less accuracy) than prior years, due to the change in instrument. For that reason, daily reviews don't make much sense, but over 3-5 day periods, the mobility and movement of the pack can still be seen.

5. As the pack begins to move around more with changes in weather systems (winds), the pack above 85N will begin to shatter more and more. By mid-month, probably only the portion of the pack firmly buttressed against the CA, will not be fractured.

6. The big threat to the CABasin ice above 85N will come from the Laptev/ E. Siberian quadrangles between 105E to 165E. This year open seas should extend above 85 N all along that front. I expect CAB MASIE extent will fall to near 2.0 million sq km, and could even fall below that by the minimum, if the Beaufort and Chukchi regions fall completely apart below 80N in the storms over the next week. That would expose the western side of the CAB ice pack to attrition.

Bottom melt season will be tough on the weakened pack.

[Espen Olsen]

Yes the Polar Web Cams have now passed the 84 line, but they are still trapped in "not going anywhere" Fram Export!

http://psc.apl.washington.edu/northpole/

[Paul Klemencic]

oops, in point 2 in my comment, I should have said from 15E to 165E, instead of 15N to 165N.

[Twemoran]

Paul
Environment Canada is showing rain at the Pole, but they make it difficult to get to the data.
If you enter at
http://www.ec.gc.ca/glaces-ice/default.asp?lang=En&n=A592A030-1#mosaics
and go to
"Arctic wind forecasts and AVHRR Imagery"
the ftp files are available. otherwise it requires a password.

Don't know why they make access so difficult.
Terry

[Neven]

For that reason, daily reviews don't make much sense, but over 3-5 day periods, the mobility and movement of the pack can still be seen.

True, but day-to-day changes have been real big at times since the last week or so.

[Andy Lee Robinson]

Looks like many Manhattans of fast ice could cut loose from NE Greenland very soon.

Ah, these would be the "Manhattan Transfers"...

[Frankd 1977]

I am changing my opinion on the SIA 2012 minimum. The SIA as of today is only 1.18 million km2 higher that the record low of last year. With roughly 40 days of melt left, I think it will come in below 2.8 million km2. Actually, if August melt averages 39,300 km2 per day, the record would be tied at the end of August!

Neven: I think this would make an excellent topic for you next update (hint hint!) :)

To all: Could anyone find it in their hearts to share a link that will bring me to a list of SIE and SIA daily data for the past few decades? I have been through NSIDC and IJIS sites and just can't find what I'm looking for.