Pinpointing the minimum

UPDATE September 16th:

Given another uptick and the current weather forecast, I'm ready to call the minimum for IJIS SIE V1 on September 12th at 5,000,313 km2. Apparently the high was too big and the pressure gradient too low to prolong things (see below).

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This blog post should perhaps have been written last week, but better late than never, right? Although it could even be too late, as the minimum might have occured already in some data sets. But if there's one thing I did right on this blog so far, it's calling the IJIS sea ice extent minimum! So let's forget all the rest and keep doing what we're good at.

Pinpointing the minimum is a slightly tricky business, especially this year with all the thin ice that didn't melt out. On the one hand this causes a lot of compaction (and some last melting) potential, but this might be offset by faster freeze-up due to all the open water between floes. Either way, it's the atmospheric situation that determines when the minimum occurs in September.

I personally re-invented this wheel back in 2010, the first melting season that was covered on the Arctic Sea Ice Blog, when comparing the end of the melting season with previous ones in a series called End Zone. In the third instalment I covered the influence of atmospheric pressure on the timing of season's end. As I wrote at the time:

Atmospheric pressures determine where low-pressure areas (cyclones) and high-pressure areas (anti-cyclones) are situated. Along the edges of such systems winds are either blowing in an anti-clockwise fashion (cyclones) or a clockwise fashion (anti-cyclones). The magnitude of the pressure determines how strong these winds are.

The way these pressure areas are distributed over the Arctic are a big factor in the annual extent decrease. Especially now, at the end of the melting season. The Beaufort Gyre, the clockwise movement of the ice pack from the Pacific side of the Arctic towards the Atlantic side, is dependent on a high over the Beaufort Sea. Combined with a low over the Siberian coast, preferably between the Kara and Laptev Seas, the Transpolar Drift Stream is activated and transports a lot of ice through Fram Strait. The stable positioning of these two poles opposite each other is known as the Arctic Dipole Anomaly.

This is what you get when that happens:

The sea ice gets compacted towards the coasts of Greenland, Ellesmere Island and the rest of the Canadian Archipelago, and it gets transported towards Fram Strait where it melts out in warmer southern waters. A double whammy, as the American expression goes.

Globally speaking you could say that a high over the Beaufort Sea, combined with low SLP on the Siberian side of the Arctic, makes for compaction and prolongs the melting season (though the rate of decrease has slowed to a trickle), despite re-freezing already occurring in different regions of the ice pack. It's the pressure gradient between those highs and lows that counts.

To help comparing with previous years I have added yet another segment on the Arctic Sea Ice Graphs page (which has now reached perfection) under SLP Patterns. This segment offers an overview of sea level pressure patterns from May to September in 6-day averages, retrieved from the Daily Mean Composites page, as provided by NOAA's Earth System Research Laboratory, Physical Sciences Division. I'm hoping this will come in handy for myself and others in the coming melting seasons. I'll try and update regularly, but drop me a line when I haven't.

If we look at the SLP patterns in September, we quickly see what kind of set-up prolongs the melting season:This is for September 13-18 2007 and it shows a perfect set-up, with an intense high over the Beaufort and low pressure elsewhere. The melting season in 2007 ended on September 24th, the latest date in the 2005-2013 period.

The same goes for 2010. Here's the 6-day period covering September 13-18:

2010 was also a tad on the late side, with the minimum occurring on September 18th, getting it within reach of 2008's minimum, which was relatively early (September 9th) because of this set-up:The high and low-pressure areas are on the wrong side, causing a lack of compaction, and low air temperatures on the Siberian side of the Arctic where all the open water is. The same goes for 2011 which also had its minimum on September 9th:By the way, I'm basing myself on IJIS' version 1 of SIE data, which was revised a couple of days ago. I simply haven't had time to update my spreadsheet yet, but I will as soon as version 1 is terminated on September 30th, 2013. Version 2 is based on calibrated and validated AMSR2 data, in other words higher resolution.

So, let's have a look at what the weather has in store for the Arctic in the coming 6 days (weather forecast by ECMWF, click for a larger version):

There's a high over the Beaufort Sea alright, but perhaps it is too big, reaching all the way to the Siberian coast. High-pressure systems make for clear skies, and with temperatures dropping, this causes sea water to release its heat so that it can freeze up. If sea water in the Siberian seas freezes up, sea ice extent won't be going any lower. The pressure gradient over the ice pack is also lower, which means less wind to compact the ice pack.

This makes me tend to say that the minimum could be reached by Saturday, September 14th, with the caveat that a big low coming in from the Atlantic might invigorate the pressure gradient, causing more compaction where the weakest part of the ice pack is situated. Perhaps the hole we discussed previously might be blown even closer to the North Pole, making enough room for the US Navy's entire fleet to park there. This animation posted by Jim Hunt on the ASIF shows progression during September so far:

We'll have to wait and see how things develop, and how the ice pack reacts.

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Some tragic news from the Arctic: Marc Thibault, commanding officer of the Canadian icebreaker Amundsen, helicopter pilot Daniel Dube and Klaus Hochheim, a veteran University of Manitoba Arctic scientist, died in a helicopter crash. May they rest in peace.

Comments

[Werther]

Nice analysis, Neven.

I suspect that the satellites will signal new ice as soon as nilas consolidates through pancake ice into young grey ice, that could rapidly accrete to 30cm.

In earlier years, extent growth would partly take place on some colder boundaries of the pack and in the marginal, protected, shallow continental shelf seas. Like the Beaufort, ESAS and within the CAA.
I didn’t check, but SIA probably shot up first as new cold impacted the CAB.
That’s what I think will happen this year too. SIA minimum will arrive soon. Extent may be jittering for some time before we can actually pinpoint the minimum.

[GreenOctopus]

Nice analysis. Interesting summary on the varying roles of atmospheric pressure during the melt and freeze seasons.

With today's NSIDC numbers, the extent pulled away from 2009 a minute too soon. Yesterday, 2013 was within 2k km^2 of tying the 2009 minimum. Unclear if it will be beat now. IJIS/JAXA's extent already has 2013 below 2009. CT area is gliding above the minimum of 2009. Vanishing odds that 2013 will fall below 2009 there. I say we have about a week left for this thing to shake out. The rest of this exercise is for documentary purposes now. I'm ready to call this melt season over to wait and see what the 2013-2014 freeze season looks like.

[Neven]

The rest of this exercise is for documentary purposes now.

Yes, it's not like there will be any big losses, but I still think it's fun to try and pinpoint the minimum, although in previous years it was mostly about calling the minimum. If extent went up two or three days in a row and the weather forecast was for low pressure dominating the Arctic, I would call the minimum.

This time I'm trying to see if I can forecast it a couple of days in advance, but like I say, that's very tricky, especially this year.

[plus.google.com/102121405461486954917]

My take on the situation is that heat that I expected to end up driving melt of the ASI went to warming the North Pacific, melting permafrost,and maybe warming Antarctica? Ultimately, I am not as interested in ice compaction as I am in storm mixing of surface fresh water with deeper salt water.

This is the first time we have actually had a chance to watch an AGW event, so I do not feel too bad about missing some of the couplings.

Today, there is more heat in the system than there was 6 months ago, so at some point, the sea ice will melt, and with more heat in the system, it will melt faster, and everyone will be more surprised at how fast
it does melt out. As long as the North Pacific is gaining heat, and supplying latent heat to Northern Canada, I do not see any chance of real ASI recovery.

[fredt34]

Isn't it amazing that the NSIDC's post for September hasn't been signaled here yet ?

He it is, nicely putting things in perspective;
http://nsidc.org/arcticseaicenews/2013/09/a-real-hole-near-the-pole/

[NJSnowFan]

fredt34 No Mention of the Worlds Largest and Nuclear powered Ice Breaking ship making a Joy ride at the end of July to the N pole this summer in that NSID's post. Seems the Worlds Largest Nuclear powered Ice Breaking ship likes taking that ice breaker to the N pole since the ship was launched in 2007. Not exactly sure if they have gone every year but videos on youtube show many since 2007

Everyone can say the ice breaking ships do no harm to the ice but cutting a path through the ice weakened by normal summer melt conditions but the ships create open water that absorbs heat speeding up the melting.

I have been tracking the ice breaking ships and some do not have their tracking signals on, I wonder why? Seems some that people that set up the arctic webcams with buoys in August were crushing the ice under the radar. I could not locate then with signal tracking websites.

50 let Pobedy tracks from about the last year.
https://twitter.com/NJSnowFan/status/371560701774823424/photo/1

[LRC]

@ NJSnowFan: Based on your theory of ice breakers making a big impact on sea ice, you should also see a very clear temperature path along the major shipping corridors of the world as these container ships are many times larger and the number of ships taking the same path many times more. You can not find it and you never will find it. It may be there for a short time but a path can not be followed in that manor over a longer period of time. The same goes with contrails that high altitude jets leave. They do add a little haze in the atmosphere, but in the grand scale of what you see in the sky after a couple of hrs. the flight path is very hard to detect. Therefore your pet theory can not be relevant as the effects of wind, water and waves are far greater then one ship carving a path through ice a 100 ft or so across and in normal circumstances recloses a few hrs later. That is why every ship going through heavy ice either is an ice breaker or closely follows an ice breaker. Even then they occasionally get stuck.

[Jim Hunt]

NJSnowFan - Have you noticed any adverse side effects on the Arctic sea ice of the Admiral Makarov's recent mercy mission? If so please could you share them with the rest of us.

Thanks in advance.

[Neven]

NJSnowFan, I'm going to have to ask you to stop hi-jacking comment threads with this particular conspiracy theory. The impact of ice breakers on the non-monolithic ice pack in summer is minimal. If you could convincingly quantify the effect as being over 2% of the total season's ice decrease, you'd have a point. But you're going to have an incredibly difficult time showing even that.

You think that ice breakers have a huge detrimental effect on the sea ice, most of us don't see how it could be more than 2%. We know all of that now. Please, refrain from redundant regurgitating. If you really have to, you could take it to this thread on the ASIF.

[Neven]

IJIS data Version 1 keeps going down so far, could go below 5 million tomorrow. CT had a couple of small upticks, so if there's no bigger drop in the coming 2-3 days, the minimum will have been reached there.

[NJSnowFan]

LRC, Jim Hunt and Neven. Ok Ok, Just keep your eyes on Polarstrern Smaller Diesel Ice Breaking Ship that is going deeper into Antarctica's Sea Ice Sheet now. Since Melt season will start soon maybe my point will be proven.
Location
http://www.sailwx.info/shiptrack/shipposition.phtml?call=DBLK

Info On the Smaller Diesel powered ice breaker
http://www.ask.com/wiki/RV_Polarstern?o=2801&qsrc=999
Ice conditions, delayed location
http://www.iup.uni-bremen.de:8084/amsr2/Polarstern_AMSR2_visual.png

Neven, I like a lot of info you post and do not agree with some of your theory's. I do NOT consider them conspiracy theory's but your own feelings.
Manny things effect Arctic Sea Ice from melting, my feelings about Ice Breaking ships is valid point is just one part of the puzzle that was not an issue before.

You say the ice breaking ships could not be decreasing the ice more then 2%. Add that 2% up ever year since the Nuclear powered ice breaking ships, larger diesel powered ice breaking ships like the uscgc healy showed up in late 70's, and get a big %. Lets say it is 1% a year, over 30 years it becomes 30% decrease.

I will stick to Trend topics from now on ok.

Thanks
Chris

[Downpuppy]

@LRC - contrails do reduce the day/night difference. 12 years ago this week, grounding all jets in the US increased the max/min spread by 1.1C -http://www.sciencedaily.com/releases/2002/08/020808075457.htm

Dimming & aerosols are a big part of climate today.(Which of course has nothing to do with icebreakers)

[Neven]

I will stick to Trend topics from now on ok.

Thanks, Chris. I'm not saying the effect is zero (and we've discussed this regularly in the past couple of years), I just think it's negligible. The Arctic is a very, very big place.

No CT update as of yet today.

[LRC]

@Neven Sorry I should not have bit and failed to remember to hesitate posting after I had posted.
Think the minimum has been reached unless a big system goes in and goes a major compaction job, I do feel though that there is too much heat in the land and oceans in NH to add a lot of volume this winter unless of course we get a continuation of cold air mass being isolated from the rest the NH

[jdallen_wa]

@LRC et al;

We may be able to measure that isolation by way of arctic breakouts this winter.

Regarding the minimum, there seem to be conflicting forces competing right now, even without the storms. Looking at SSTs from NOAA, it seems like we could still have limited bottom melt thinning even while we start a refreeze. Time to start pouring over buoy data again.

[Susan Anderson]

"NSIDC is closed today because of severe weather and flooding. We are sorry for any inconvenience this may cause you."

Boulder Colorado is on disaster alert today:
http://usnews.nbcnews.com/_news/2013/09/12/20450541-flash-floods-wash-away-homes-kill-at-least-3-near-boulder-colorado

stolen from Wunderground Masters comment:

The emergency radio feeds out of Boulder are pretty harrowing right now.... the rain continues to fall... multiple reports of Natural Gas Main breaks.

[GreenOctopus]

Understandably, too. About 7-10" of rain in 24 hours, obliterating the previous record in 1919.
http://denver.cbslocal.com/2013/09/12/boulder-breaks-rainfall-record-set-in-1919/

"The City of Boulder has broken a rainfall record set more than 90 years ago. Boulder has received seven to 10 inches of rain in the past 24 hours. That breaks the previous record of 4.8 inches set on July 31, 1919.

A flash flood warning remains in effect for Boulder County until 8:30 p.m. Thursday. All City of Boulder facilities, including libraries and recreation centers, will remain closed on Friday."

Three lost their lives, many homes have been flooded. Terrible situation.

For what it's worth, 5-day moving average of NSIDC extent (before site went down) was lower than 2009's 5-day min. Daily extent still slightly above 2009 as of 9/11/13.

[Doug Lofland]

Tweet from @spogburn in Boulder, 2013's missing Arctic ice located: after a phase change it's headed down Boulder Creek towards #NSIDC.

[Susan Anderson]

That's a choke on laughter tweet, thanks.

I apologize for having started a strange off/on topic diversion. However, in my researches (since there were wildfires that threatened NCAR in Boulder last year) I found this gem for those interested in Arctic effects and knock-on consequences, if a mite elsewhere-centric.

http://www.theepochtimes.com/n2/opinion/climate-change-hits-home-302120.html

"Climate Change Hits Home: A warming Arctic affects all of us"

[Ostepop1000]

There is a slight lurch of the "hole" towards the pole, but it will never get anywhere near as temperatures at the pole are already down to 12 degrees below zero (celsius) at night, and sunlight is getting scarcer by the day. Open water freezes over in these conditions in calm conditions, which is what we have at the moment.

I still think we will se a late dip in extent though, as there is still a lot of warm water and air in areas of relatively thin ice.

As melting seasons go, this will not beat any records in minimum extent, but it might well beat the record of latest minimum.

Not a prediction, just a possibility.

[Doug Lofland]

I should not be making fun at the Boulder flood, its becoming a very serious situation. But it may not be that off topic. While everyone is looking at the ice minimum, and no new record being broken (or their predicted minimum not happening) a record that might be broken this year is the extent of the open ocean between Greenland and Sevemaya Zemlya (or Greenland/Barents/Kara Seas). I am going to CAD it as soon as the minimum is reached, and see how it compares to other years.

The fact that it extended as far north as it did, and the lack of ice off East Greenland may have created the largest "heat island" in that part of the world, which may skew/lock/alter the jet stream in ways we have not seen yet.

The extreme weird weather just keeps a coming, everywhere you look.

[Ostepop1000]

And the more you look, the more you see, Doug.

[NJSnowFan]

Doug, There in no extreme weird weather, it is just how it is presented to the public Extremely Fast. It is Extreme weird media reporting. How do you think the canyons formed out west. This type of weather events with big floods over millions of years.

The Ice off Greenland is less because it is jammed up from the coldest summer on record. Warm summer would of allowed the flows to migrate south more. Less ice now will only allow water to cool down deeper making a nasty winter for Europe.Snow has been falling all summer in Greenland and more then half of Greenland had no summer melt at all.
Hope you have your long johns ready,Dalton like minimum has already started. Things can get real cold fast just like it can get hot.

[Colorado Bob]

"The Ice off Greenland is less because it is jammed up from the coldest summer on record."

Prove this NJSF, I mean the "coldest summer on record." part.

[Doug Lofland]

NJSF, You should take up terminology issues with NOAA and the NWS. Tonight they used "1,000 year" and "biblical" to describe the ongoing events in Colorado. http://tinyurl.com/l8wnr63

My sources for weather watching are Neven, Dr. Jeff Masters and Christopher Burt, not the sensationalized media, and I could not think of a more cautious and conservative group that puts a great deal of effort to get the information right.

It will take months to understand what led to the conditions, why the ice is where it is (and is not), and all this through satellite eyes 700 kms out in space.

I don't have long johns and have not had weather in 2 years here in Miami where I have needed to wear anything other than shorts. I would welcome cool winters again, being able to shut the A/C off. I would love to see the old patterns return, that were here for so many years. I would love to see the tropical zone stop creeping north, and sea level rise stop or reverse.

Thanks to websites like this that lurkers like myself can learn a little about what is going down on the planet.

[Hans Gunnstaddar]

Doug L. "I would love to see the old patterns return, that were here for so many years. I would love to see the tropical zone stop creeping north, and sea level rise stop or reverse."

I find that interesting because we had an unusual Summer this year (a couple hours drive north of SF and about an hour's drive east of the coast). So many warm nights translated into needing to run the AC to get to sleep or not getting very restful sleep. Lots of sub-tropical weather systems moving north threatening but not usually bringing rain making for muggy weather. Usually at 1200 ft. elevation our nights are cool and this area is usually dry - but so much for what use to be the norm. I'm worn out and keep hoping for cooler weather, but alas tomorrow's high, 95F. Right now it's 10:46 pm and it's 75.4 out and 81 in. I want it to be 65F or less inside to get to sleep. Stick a fork in me, I'm done.

[Phil263]

SIE now under 5 million (IJIS Version 1 pending correction): 4,997,188 on Sep 12

[GreenOctopus]

"Hope you have your long johns ready,Dalton like minimum has already started. Things can get real cold fast just like it can get hot."

Dalton minimum, eh? Hope you're exaggerating. The folks at NOAA seem to think winter 2013-2014 is going to be somewhat unremarkable for cold weather.
https://lh6.googleusercontent.com/-_ZNU5AJkLL4/UjMVETiS44I/AAAAAAAAALk/ToanLZmiC5Q/w831-h642-no/glbT2mSeaInd3.gif

Back to sea ice: IJIS version 2 now showing 9/12/2013 slightly lower than same day 2010.

[L. Hamilton]

The massive flooding in Colorado, variously described now as 100-year, 500-year or "Biblical" results from a low-pressure system stalled over the area this week. No proof that a single event reflects climate change of course, but this one fits the pattern of changes toward more persistent mid-latitude NH weather that Jenifer Francis and others have described as a consequence of Arctic warming.

[LRC]

@LH: Based on location (have not followed weather reports), sounds like what happened in Calgary, Canada earlier this year. There what happened was a swirl broke off of the jet stream and kept throwing a system back up into the mountains making it rain there instead of farther east.
As for what may happen this winter: from Accuweather:
I will be issuing the AccuWeather Canada forecast for Fall 2013 next week.

Here are some of the key points from the ECMWF model forecast....

1. Unseasonably warm for the Fall from extreme NW Canada to Atlantic Canada.

2. Warmer than normal for the SW U.S. in the Fall.

3. Near-normal Fall temperatures from the southern Prairies to extreme southern Ontario.

4. Wetter pattern for western BC this Fall, but drier than normal for Atlantic Canada.

5. Warmer-than-normal winter for Alaska and much of NE Canada, including Newfoundland.

6. Near-normal temperatures from BC to Ontario and southern Quebec.

[L. Hamilton]

Forgot to note why I mentioned the Colorado floods in this thread: that's the reason NSIDC has been down today. They are in Boulder which has been hard hit by the flooding. Major roads in the region have been cut, and some smaller towns evacuated. Don't know how this affects NSIDC, but the University of Colorado nearby reports many flooded buildings.

[Paul Klemencic]

More data to support Jennifer Francis and Steve Vavrus; extreme weather is being causing by changes in jet stream behavior.

The Colorado floods were caused by a big blocking HP systems stuck over Canada and the Eastern US. Jeff Masters had this to say (please note that the rainfall amounts are off the charts; each of the last three days saw rainfall that roughly matched the MONTHLY rainfall record for this area):

Colorado's epic deluge is finally winding down, as a trough of low pressure moves across the state and pushes out the moist, tropical airmass that has brought record-breaking rainfall amounts and flooding. Devastating flash floods swept though numerous canyons along the Front Range of Colorado's Rocky Mountains Wednesday night and Thursday morning, washing out roads, collapsing houses, and killing at least three people. The flood that swept down Boulder Creek into Boulder, Colorado was a 1-in-100 year event, said the U.S. Geological Survey. A flash flood watch continues through noon Friday in Boulder. According to the National Weather Service, Boulder's total 3-day rainfall as of Thursday night was 12.30". The city's record rainfall for any month, going back to 1897, is 5.50", so this week's rainfall event is truly extraordinary. Some other rainfall totals through Thursday night include 14.60" at Eldorado Springs, 11.88" at Aurora, and 9.08" at Colorado Springs. These are the sort of rains one expects on the coast in a tropical storm, not in the interior of North America! The rains were due to a strong, slow-moving upper level low pressure system to the west of Colorado that got trapped to the south of an unusually strong ridge of high pressure over Western Canada. This is the same sort of odd atmospheric flow pattern that led to the most expensive flood disaster in Canadian history, the $5.3 billion Calgary flood of mid-June this summer. The upper-level low responsible for this week's Colorado flood drove a southeasterly flow of extremely moist tropical air from Mexico that pushed up against the mountains and was lifted over a stationary front draped over the mountains. As the air flowed uphill and over the front, it expanded and cooled, forcing the moisture in it to fall as rain. Balloon soundings from Denver this morning continued to show levels of September moisture among the highest on record for the station, as measured by the total Precipitable Water (PW), which is how much water would fall at the ground if the entire amount of water vapor through the depth of the atmosphere was condensed. Four of the top eight all-time September highs for Precipitable Water since records began in 1948 have been recorded over the past two days:

1.33" 12Z September 12, 2013
1.31" 00Z September 12, 2013
1.24" 12Z September 13, 2013
1.23" 12Z September 10, 1980
1.22" 00Z September 2, 1997
1.21" 00Z September 7, 2002
1.20" 00Z September 13, 2013

Wunderground weather historian Christopher C. Burt discusses how this year's flood compares to previous Colorado floods in his latest post.

[Paul Klemencic]

I would also like to note, that the flow of moist air went WEST, not east as we would normally expect. This fronts moving left, instead of right, matches the highly peculiar path and behavior of Hurricane Sandy, and the LP system Sandy combined with. That occurred late last October, and was caused by a blocking HP areas stuck over Baffin Bay and the Labrador Sea.

Every year we are seeing confirming extraordinarily rare weather events in the NH that conform with the Francis and Vavrus hypothesis. We are now entering the eighth autumn since the blowout melt year of 2007, and every year evidence of altered jet stream behavior mounts.

[profmpiya]

An important characteristic of the Earth's atmosphere is its pressure as it often determines wind and weather patterns across the globe. By definition, atmospheric or air pressure is the force per unit of area exerted on the Earth’s surface by the weight of the air above the surface. The force exerted by an air mass is created by the molecules that make it up and their size, motion, and number present in the air. These are important factors because they determine the temperature and density of the air and thus its pressure. Air pressure is not uniform across the Earth however. The normal range of the Earth's air pressure is from 980 millibars (mb) to 1050 mb. These differences are the result of low and high air pressure systems which are caused by unequal heating across the Earth's surface and the pressure gradient force.

[VaughnA]

Hans, I am about 600 miles due north of you. I concur with what you are saying. Two days ago it was 100F and humid. A week before that I got about 4.5" of rain in 24 hours from one of those cutoff lows. Was hot and humid then too with temperatures in the 70s to low 80s F with the heavy rain. There was minimal flooding because the ground was parched when the rain started. This type of weather is certainly becoming more common.

[LRC]

Makes me wounder when are we going to stop calling all these events 1-100 yr event. For a specific location maybe(although even that is changing), but it used to be a 1-100yr. event was meant to include an entire geographical region. So many of this events are happening every year in even geographical regions (although different variations granted) that 1-100 yr. event although catastrophic for the location you can almost start calling them as common as cat 3+ hurricanes hitting Florida. Maybe not frequent, but not unusual and should not be surprising giving how big the changes are occurring especially related to the jet stream, which was predicted quite a while ago is it would start slowing down and become erratic as a result of decline of ASI.
PS that was a long unwieldy sentence but am too tired to try an figure out a better way of saying it. Good night.

[Hans Gunnstaddar]

Thanks for sharing VaughnA. Wow, even 600 miles north! And now this sub-tropical system deluging parts of Colorado. This is the problem with a dropping temp. gradient between the Artic and the tropics, as three distinct weather regions in the NH are melding to some extent into a more homogenous system.

[Jim Hunt]

NJSnowFan - A convoy consisting of four nuclear powered icebreakers and ten vessels from the Russian Northern Fleet, including the flagship "Peter the Great", have just cut the remaining ice on the Northern Sea Route into ribbons.

Can you discern any adverse side effects of all this sudden activity in any satellite image? If so I'd love to see it!

[Neven]

A 26K uptick on IJIS SIE version 1. If that big high that is now in place, prevents further compaction (or doesn't cause enough of it), the minimum has been hit, because it's forecast to stay in place for at least another week (atmospheric blocking?).

[Phil263]

If Sep 12 was indeed the minimum for SIE IJIS, 2013 did not quite make it under 5 million. The figure for Sep 12 was revised upwards to 5,000,313!!!

[Lord Soth]

Actually IIJS was at 4809288 as of Sept 12. You are quoting IIJS Version 1, which is now obsolete (and will finish reporting on Sept 30).

IIJS Version 2.0 is higher resolution and much more accurate. Also they have adjusted IIJS Version 1 numbers to reflect the new algorthim.

As of yesterday, we were below 2010, but you are right, I don't expect the late season dip we saw in 2010, so 2013 will likely finish in 6th place.

[Phil263]

Hi Lord Soth
I am aware that IJIS has now two versions for its graphs. I agree with you that Version 2 is more accurate; but for the sake of consistency, I think Version 1 is a better gauge at least until the end of this season as predictions and comparisons were made on the basis of Version 1.

[VaughnA]

Hans, it will be very interesting to see if these types of systems become more common throughout the fall and winter as well. Imagine what one of these lows could do in the fall if it contains all this tropical moisture already then moves into a comparatively cold moist environment.

[Shared Humanity]

"...it will be very interesting to see if these types of systems become more common throughout the fall and winter as well."

We are already seeing the winter effects throughout the northern hemisphere. Blocking patterns and a stalled jet stream are delivering sporadic record breaking snowfalls. Scotland was decimated last winter by a snowfall that resulted in 15' drifts.

[wayne]

Examples from the unknown abound. Huge big lead event is occurring now... http://eh2r.blogspot.ca/ .

The biggest reason for this years apparent greater sea ice extent is from dominant winds canceling the Arctic Ocean clockwise Gyre. As a consequence the pack is loose even near Ellesmere Island. THerefore the minima may be delayed....

[Neven]

Another uptick, now more than 50K above the low reached on Sept. 12th. I'm about ready to call the minimum.

[NJSnowFan]

Colorado Bob

"Prove this NJSF, I mean the "coldest summer on record." part."

According to DMI records going back to 1958, 2013 Arctic temperatures above 80 North is or very close to the coldest summers on record.

It turns out the 3 coldest Arctic summers have all occurred in the last 5 years. - See more at: http://notrickszone.com/2013/07/28/cooling-poles-top-3-coldest-arctic-summers-will-have-all-occurred-in-past-5-years/#sthash.cLP5FGjN.dpuf

Here is the DMI Data on Arctic Temps click on temps back to 1958

http://ocean.dmi.dk/arctic/meant80n.uk.php

[NJSnowFan]

Jim Hunt
"NJSnowFan - A convoy consisting of four nuclear powered icebreakers and ten vessels from the Russian Northern Fleet, including the flagship "Peter the Great", have just cut the remaining ice on the Northern Sea Route into ribbons.

Can you discern any adverse side effects of all this sudden activity in any satellite image? If so I'd love to see it! "

Jim makes little difference this time of year, My main concerns were from at end of winter through summer melt season. Shallow water is much colder now and ice that already starting to refreeze.

[TuringMachine]

Neven:

Do you track max point as well? One of the signature of warming would be increasing melting season days from max to min, and the error estimate in pin pointing.

[Chris Reynolds]

NJSnowFan,

Gosselin hasn't a clue what he's talking about.

It's been cold, certainly in comparison to recent years, but by NCEP/NCAR it is certainly not the case that "Top 3 Coldest Arctic Summers Will Have All Occurred In Past 5 Years". And as for the bet...

"I’d bet a good bottle of Scotch that we’ll be seeing a rising Arctic sea ice trend over the next 10 years."

I'm seriously pondering upping the stakes on that.

DMI use ERA40, but the difference between the two reanalyses isn't so massive that the take home message of this graph is negated:

When Gosselin calls his blog 'notricks zone' it is a warning. The other warning is the lack of a timeseries and just a few snips!

Referring to that site calls your judgment into question.

[wayne]

Wipneus , replied about the winds on http://eh2r.blogspot.ca/.

Neven, I note AMSR2 presentation not showing dramatic increase, although 50K is small. I suspect the numbers to be trumped by that 15% area rule, or the interior of the pack might be freezing easier because there is floating just melted fresh water and no wind mixing up the layers. Compaction should continue for sometime while this process goes on.

[Mark Arnest]

Since we're going to hear a lot about his year's historic rebound in arctic ice, it's especially important to keep things in perspective: This year's minimum is lower than any year recorded prior to 2007. Or: Just seven years ago, this would have been a record low. The real story isn't the rebound, but how quickly the ice coverage has shrunk.

This otherwise-optically-confusing version of the arctic sea-ice monitor works well here: http://www.ijis.iarc.uaf.edu/seaice/extent/Sea_Ice_Extent_v2_prev_L.png

[Hans Gunnstaddar]

VaughnA: "Imagine what one of these lows could do in the fall if it contains all this tropical moisture already then moves into a comparatively cold moist environment."

Wasn't that what happened with Sandy on the east coast? Two converging massive storms, one cold, the other warm. As for the West coast I remember seeing a special on TV in which there was speculation that with a warming climate, the weather could shift to bring water drenched tropical storms farther north that would deluge the LA region causing massive mud flows. Whether or not that comes to pass we are certainly into a certain degree of climate change already and how bad it gets all depends on this experiment we are conducting to see how increasing CO2 levels impact the weather.

[Chris Reynolds]

Wayne,

See the NCEP/NCAR plot in my post above.

I have said on my blog that:

"Throughout the season it has been tempting to view cooler temperatures as causing reduced melt, but less sea ice (meaning more open water) may be what is driving temperatures upwards, and more ice this year may have suppressed temperatures. Despite the lack of relationship between SLP and June loss shown above, there is a relationship between temperature and June loss, but this may be caused by sea ice loss, not causing sea ice loss."

However I think that while more ice has been part of the reason for the cold, atmospheric circulation must have played a role.

I have not reached a solid view of this year in terms of the atmosphere, what follows is my initial impression. PIOMAS volume was less than 2012 before May, but more after. This suggests to me that the pivotal conditions were in May. After that in June ice recession was retarded and cold conditions remained through the ice pack preventing the Greenland ridge and post 2007 summer pattern from developing, this then persisted through the summer.

So regards your blog post:
http://eh2r.blogspot.ca/2013/09/cooler-air-reducing-sea-ice-melt-not-so.html
I have said in comments at my blog that I agreed in general with this. I now think it is but part of the reason for the cooling, and that circulation this summer (lack of Arctic Dipole?) has played a role.

I still maintain my strong disagreement with this statement of yours:

"The great 2013 dispersal of sea ice masked the actual melt especially when using standard statistics."

PIOMAS has continued to be accurate this year, and correctly shows that volume loss this year has been muted compared to the other post 2010 years. It is not the case that 'actual melt' has been greater than PIOMAS indicates. While increased ice implies less warming due to less open water, comparing extent/area this year with other years in no way explains the severe drop in temperature this year.

[NJSnowFan]

It is really sad, we have the technology to figure out many problems and solutions like never before.
Most Climate Scientist
Use climate models(selected data is put in first) to predict future outcomes not like the so called arm chair deniers like my self that use hard data facts from the past to predict future outcomes.
If you use a computer climate model and do not add one event/outcome exactly right the models calculations will be way off going forward in time. One problem will add more problems to the same one and over time the estimate will be way off.

Many people who only look at media for news on the climate will be brainwashed. May TV news outlets are running the what IF shows on weather, climate, and asteroid like
dooms day events are really messing up the minds of many.

[NJSnowFan]

snip

[Thank you, that will be all; N.]

[mabs]

NSF, quite a piece of revelation you've got there. Blew my mind, it did. Do you think it's maybe because them scientists haven't figured that out? Maybe they don't know. You think? I think you should go tell them. Take your three graphs with you and show them how it's done. Show them your hard data! Poor lost souls! They dwell in ignorance without you! They have nothing better than the media to get their information from. Go! Save them! Why are you wasting your time on this blog!? Go!

[NJSnowFan]

Chris Reynoslds, almost any bet you make against, I will take.

Man up..

Look at ALL the past data, any bet you make you will lose.

OK, I have an inside tip, look at the sun.

[wayne]

It was a dynamic road fork Chris, summer 2013 sea ice would have done 2012 record trends given the same compaction, but the winds turned the other way around the clock. Quite an extraordinary season if you think of it. Of course counterclockwise winds make cyclones. Any enhanced cloud cover during summer cools the air , and finally scattered ice cooled temperatures further. The flow of moist North Atlantic air added to the clouds and created the early snow carpets for CAA, record warm North Pacific sst's also contributed. If the winds turned the other way we would be less amazed. It is fundamentally misleading to say that the Arctic cooled because greenhouse gas theories are wrong.
Because this years melt was tempered by extraordinary strange stable dynamic meteorology .

As far as Piomas is concerned I have basic questions about its volume calculations, the overall thickness of the ice is thinner than last year, yet there is more volume. This leads me to posit a possible flaw perhaps by the the thresholds used. Or, if it is accurate, the ice melted more than last year, and there was no compaction which should enhance the melt further. Or the ice melted more than last year and the statistical methods used to judge a melt should be re-evaluated by removing compaction, similar to removing ENSO from the Global temperature trend.

[Susan Anderson]

NJSnowFan is preventing interesting real people from talking about interesting real stuff and free with insults along with boring rebunking of long-dead talking points.* Enough already. Seems to want to be in charge, for which I'd suggest starting own blog, not infesting somebody else's.

*try this for easy to digest and more thorough well referenced answers. Deniers don't like it because it saves reinventing the wheel:
www.skepticalscience.com

In twitterese: Deniers attack @SkepticScience because it is so effective.

[Dan Ellis-Jones]

OK, NJSnowFan, I've been holding my tongue as responding to you is just a waste of time, but I'm doing this to make myself feel better.

I've worked with climate modellers in Australia. Firstly, they will admit that their models don't always get it right...

This is a brief simplification of their process… Before they publish any findings, they develop and test the model for months and years. Then they put in historic data to get the model to predict climate/weather that's already happened... so 1980's data to predict 1990/2000's weather/climate. They then adjust the model to provide an accurate picture that can be relied upon if there is any discrepancy.

Once the model accurately predicts past weather, they will undertake a huge number of runs with minor changes to the inputs and see what they give. Then after all that they finally publish outputs that are the average of all the runs they've made.

I think if you did some proper research you will find that many models are very close to real life outcomes. Those that are off tend to present the situation as much less severe than reality - eg the speed and extent of Arctic sea ice loss is a good deal worse/quicker than most models have predicted.

So, they don't always get it right, but that's not a reason to think that the planet isn't warming, and that GHGs aren't going change our climate. The models are just predictive tools. Deniers are predictable tools (not that I'm saying you're a denier NJSnowFan - just speaking generally).

[LRC]

@DE-J: I do admire your efforts. As you point out where models have not worked is underestimating severity. It goes back to the old problem of the butterfly in Beijing, It will never be possible to get all the perimeters involved to the degree they are involved as it is a chaotic system over all. I do say that the models are getting better, but they are never meant for what happens year to year. They are only meant for the long run.
Keep up the good work, for even when you do get things wrong we are still getting closer to what the truth is.
Just remember that hurricane et al and tornado forecasts are based on models. They never get it exactly right, but when listened to save countless lives and damage.

[Dan Ellis-Jones]

Thanks LRC - Just to clarify, I'm not a scientist/modeller myself, but I've worked with some scientists on trying to make the scientific outputs more accessible/understandable to policy makers and developers (that's me) and the general public (oh, that's me too!).

I've said on this blog before, that I think there is a definite trend where the more we know, the more we realise we don't know, and are surprised at how the real world reacts (This is a truism for most things!). But much more often than not, the real world reacts quicker and more severely than the models predicted.

And, yes, the models don't (aren't meant to) predict how each year will play out. And it depends on what the model is trying to determine. The models predicting the ENSO status are almost always on the money, for instance. I would recommend the Australian Bureau of Meteorology website for some great background info - www.bom.gov.au

Also, on weird weather - eastern Austrlia has had bush fires and record high temps already this season - remembering Sept is the SH equivalent of March. Imagine having wildfires in California/Arizona in March!

[Chris Reynolds]

NJ Snow Fan,

The terms I offer are based on P Gosselin's claim that the ice will recover over the next ten years, to which I assume you subscribe. However the term of the bet will end on 30 Sept 2020. I am not willing to wait ten years.

The bet is as follows:

Using NSIDC daily extent data. I bet that the average of daily minimum extent for the seven year period from 2014 to 2020 will be lower than the average of daily minimum extent for the seven year period from 2007 to 2013.

The bet is £1000.00 UK Sterling to be redeemed on 30 September 2020 at exchange rates effective on that date.

You have no inside information, you just don't know what you're talking about. See figure 4 of Notz/Marotzke on this blog post.
http://dosbat.blogspot.co.uk/2012/05/co2-causes-arctic-sea-ice-loss.html
The second panel shows the relationship between insolation and sea ice.

It is telling that you have failed to acknowledge that Gosselin is wrong.

Wayne,

I'll respond when I have more time after work.

[VaughnA]

Hans, I agree the blocking highs and cutoff lows are becoming much more common. Last year in January we had an intense blocking high over this area for about 2 weeks. Air temps at 2000 feet elevation were 50 to 60 F in very dry air. Surface temps were about 28 to 32 F day and night in fog and it even snowed a few places under the warm cap of air which is something I had never seen before(snow under a dome of very warm high pressure.)
However, I do not believe they are the dominant feature at least not here...yet, as the weather seems to eventually return to a more "normal" progression of fronts crossing the coast in the winter and the normal high pressure off the coast in the summer.
If however, the blocking highs and cutoff lows become the dominant features or the only features then it is pretty clear...at least from the tastes we have had from them so far...that all hell will break lose.
Since the trend for more blocking highs and cutoff lows is noticeably increasing over the past few years the time to change completely over may not be too far off unless something happens to stop the change.
Interestingly, I was down on the north Oregon Coast today wading in the Pacific Ocean and the water was so warm it barely felt cold...something which just doesn't happen here, as the water usually feels ice cold. I didn't have a thermometer but I am guessing the water temp was around 65F, which would be highly unusual.
Also, after I consulted the map a little closer, I think I am closer to 500 miles due north of you, just north of Portland, OR.

[John Christensen]

Chris said:

"PIOMAS volume was less than 2012 before May, but more after. This suggests to me that the pivotal conditions were in May."

While I agree with your direction, I actually think the difference was established during those two freezing seasons:

It is necessary to consider the geographic distribution of the volume, and the late winter/early spring of 2012 saw lots of ice in Bering, Baffin, and Hudson, while the same period in 2013 was showing less volume in these seas, but more in Beaufort, CAA, ESS, etc.

Therefore, while overall PIOMAS volume in 2012 was comparable to 2013, the difference became clear by June as the more southernly seas melted out, and the added volume this year in more central seas (added due to the SSW event and cracking) combined with very favorable weather made the whole difference.

Imagine if PIOMAS would break down their data by individual seas..

[John Christensen]

Sorry, let me correct myself:

Okhotsk, Bering, and Baffin had more ice in spring than 2013 - probably not Hudson.

In the CT compare for April 1st of 2012 and 2013, the difference is clear:

http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=04&fd=01&fy=2012&sm=04&sd=01&sy=2013

It is also interesting to note the improved snow cover overall in the NH in the first months of 2013, which was still visible by April 1st, but changed rapidly during the month of April.

[NJSnowFan]

Neven, " snip

[Thank you, that will be all; N.]"

Not sure what was posted where you sniped it, was not me and think one of my friends might of used my tablet at the B day party.

snip

[Don't have time for the trolling, NJ. As 97% of what is written on blogs like WUWT and notrickszone is untrustworthy and/or intentionally misleading, I don't want too much linking, especially if it's off-topic. So, I'm sorry, but next time I'll have to ban you from this alarmist echo chamber, N.]

[Jim Hunt]

I'm sure this will interest you NJSnowFan - Amongst many other things, it contains an interview with Wieslaw Maslowski from 2007 in which he discusses his views on when the summer Arctic sea ice extent might reach a minimum of zero:

http://greatwhitecon.info/2013/09/shock-news-why-isnt-the-arctic-ice-free/

You will note that what Wieslaw actually said was:

If we project this trend ongoing for the last 10 - 15 years, we probably will reach zero in summer some time mid next decade.

[Neven]

Given another uptick and the current weather forecast, I'm ready to call the minimum for IJIS SIE V1 on September 12th. Apparently the high was too big and the pressure gradient too low to prolong things.

Another one of Chris Reynolds' comments got caught in the spam filter (sorry, Chris!). I've released it and here it is again in full:

NJ Snow Fan,

The terms I offer are based on P Gosselin's claim that the ice will recover over the next ten years, to which I assume you subscribe. However the term of the bet will end on 30 Sept 2020. I am not willing to wait ten years.

The bet is as follows:

Using NSIDC daily extent data. I bet that the average of daily minimum extent for the seven year period from 2014 to 2020 will be lower than the average of daily minimum extent for the seven year period from 2007 to 2013.

The bet is £1000.00 UK Sterling to be redeemed on 30 September 2020 at exchange rates effective on that date.

You have no inside information, you just don't know what you're talking about. See figure 4 of Notz/Marotzke on this blog post.
http://dosbat.blogspot.co.uk/2012/05/co2-causes-arctic-sea-ice-loss.html
The second panel shows the relationship between insolation and sea ice.

It is telling that you have failed to acknowledge that Gosselin is wrong.

Wayne,

I'll respond when I have more time after work.

Maybe put in the big-volcanic-eruption clause.

I personally wouldn't take that bet if Pierre Gosselin had influenced my thinking, unless he'd be willing to chip in.

[Chris Reynolds]

John Christensen,

PIOMAS do break down their data, this year they have been good enough to provide gridded data up to May, here is the difference between 2012 and 2013.
http://farm4.staticflickr.com/3672/8988350542_ae5ec32f02_o.png

Baffin, Hudson were virtually the same. In in Beaufort and the Atlantic sector was thicker in 2012. Ice across the Siberian sector was mixed.

But to blame it on distribution of ice is to ignore the colder conditions over most of the pack in May.
http://farm6.staticflickr.com/5443/8961022081_01c4ff09dc_o.jpg
And the colder conditions in June:
http://farm8.staticflickr.com/7438/9202895792_9ea69a751e_o.png

[Chris Reynolds]

Wayne,

But we're left with the extremity of the temperature drop this year. I cannot envisage that temperature did not play a role now I see how severe the cold was.

Neven,

When making bets I always assume that 'force majeure' applies implicitly. I don't think anything other than a Toba, Yellowstone volcanic eruption or a KT type asteroid impact would apply to a seven year average. But by the same token a massive ash cloud falling on the pack in May causing a total melt out by August would mean I would call the bet off.

What NJSnowfan does with regards financing his payment to me should he accept is up to him. The reverse isn't something I need consider. The bet is a dead cert for me. The terms of the bet can be calculated for every year from 1985 to 2006 - over that period every year I win.

The bet only fails if the ice starts an extended recovery. In that sense it's a sound test of mettle.

[NJSnowFan]

Jim hunt,
I just do not see that happening anytime soon with past history repeating with the sun now.
I feel have just ended the modern maximum and started entering a Dalton minimum type pattern. Current sun spot cycle #24 is tracking what #5 did. Sunspot cycle happened in the Dalton Minimum.

Chart
http://en.wikipedia.org/wiki/File:Sunspot_Numbers.png

[NJSnowFan]

"Chris Reynolds'

The bet is as follows:

Using NSIDC daily extent data. I bet that the average of daily minimum extent for the seven year period from 2014 to 2020 will be lower than the average of daily minimum extent for the seven year period from 2007 to 2013."

The bet is £1000.00 UK Sterling to be redeemed on 30 September 2020 at exchange rates effective on that date."
CR
Lets switch it up some, 2013 to 2020 will be lower than the average of daily minimum extent for the seven year period from 2007 to 2013." is ok
2013 is the start of the Ice recovery with current sunspot cycle #24 and the flushing of the volcanic Ash form the 2011 volcano. I feel giving you 2013 year included in the bet would be giving you some extra free point but you need them so including 2013 is ok.

$$ may have not much value by 2020 so lets stick to a 21 year old bottle of Glenlivet.
Bet will end with a paid shipment of the Glenlivet to the winners location.

http://www.masterofmalt.com/whiskies/the-glenlivet/smiths-glenlivet-21-year-old-whisky/

[Chris Reynolds]

"....perhaps it should not be that surprising that during the Little Ice Age there was a small recession of the Arctic sea-ice, rather than an increase."

http://dosbat.blogspot.co.uk/2011/12/arctic-sea-ice-in-little-ice-age.html

[Chris Reynolds]

NJSnowFan,

Including 2013 is actually to the detriment of my position, not to my advantage.

I don't drink alcohol. £1000.00 or nothing.

[John Christensen]

@Chris,

Thanks for the great data analysis! I had been fantasizing about the impact of the SSW event since early June, but see that this is uncalled for, and that a large part of the central pack was left thinner than in 2012 and thereby seem to have been saved solely by the low temperatures caused by the lows.

As Mark Serreze argues (from the 'On persistent cyclones' entry):

"Results from the present study suggest that, at least in part, the summer cyclone pattern owes its existence to differential atmospheric heating between the Arctic Ocean and snowfree land".

A couple of thoughts:
1) Did the fast continental warming by early/mid-May cause the cyclone activity to be triggered due to the temperature difference between land and ice?, and/or
2) Did the increased ice at the 'fringes'; ESS, Beaufort, CAA and Kara help play a role in triggering Arctic lows (CT regional maps showing least negative anomaly since 2001 for ESS, since 2003 for Kara and CAA, and since 2005 for Beaufort)?

[NJSnowFan]

"NJSnowFan,

Including 2013 is actually to the detriment of my position, not to my advantage.

I don't drink alcohol. £1000.00 or nothing."

Well I guess there is NO bet then.

Lets just keep the bet as bragging rights then as man to man.

p.s. Nothing in the article about the PDO flip and how it can effect Arctic Sea Ice. I forgot to add it in my above post.

[Chris Reynolds]

PDO Flip?

As posted previously.
http://dosbat.blogspot.co.uk/2012/05/co2-causes-arctic-sea-ice-loss.html

See the second graphic, 3rd panel from the left. PDO has even poorer scatter plot relationship with sea ice than TOA total irradiance. Both have extremely poor grouping when compared to CO2 (first panel of that graphic). AMO was given in a separate plot at the end of the post at the request of Neven.

No bet then.

[Neven]

I'm open to the 'PDO flip' as influencing the Arctic and its sea ice somehow, but what exactly is the mechanism?

[NLPatents]

Anyone know why the US sea ice area stuff hasn't updated in almost a week? Normally they dont' get more than 3 days behind.

(Maybe they don't like having their announcement of the minimum scooped?)

[Jim Hunt]

NLPatents - Because Boulder is under water:

http://econnexus.org/biblical-floods-in-boulder-close-nsidc/

[Chris Reynolds]

Neven,

The Notz and Marotzke paper finds that using a 58 year dataset the scatter plot of PDO relationship with sea ice decline has an R2 of 0.04. R2 (R squared) varies between 0 (no variance explained) to 1 (all of variance explained).

It might be possible to improve on the R2 of 0.04 for the PDO using a more advanced statistical method. But it is very hard to see how such improvement could bring the amount of variance explained to anywhere near that of CO2 (R2 of 0.84 - almost all variance explained).

The AMO (Atlantic Multi-Decadal Oscillation) is a more likely candidate as it plays a role in ocean heat transport to the North Atlantic. However even in this case the R2 is only 0.015 for the period 1950 to 2007.

[wayne]

Chris, "the extremity of the temperature drop this year."

true, same as today;

http://www.esrl.noaa.gov/psd/map/images/fnl/sfctmpmer_01a.fnl.html

as with the recent past the cooling was largely restricted to the pack and CAA, not all over.

Melting is said to be from 2/3 sea water 1/3 air, if the cooling was restricted over the mixed pack clouded area, then the cooling was a factor of 1/3 over a smaller area of the entire Arctic. A month ago or so, the North Pole region was first covered with water a top of ice , then broke up with 50/50 open water later. Would a cooling do this?

CT analysis (what is available) is not showing a minima just yet.

[jdallen_wa]

I do like scotch. I'll take your bet, NJSF. Only caveat is the "big event" clause, either way - something like a VEI 7 event - that jerks the average out of shape.

In that event, the median might be better than the mean.

[A Facebook User]

Looks like we have hit the minima, the graph has levelled while the NSIDC has been offline. Who guessed right? http://nsidc.org/data/seaice_index/images/daily_images/N_stddev_timeseries.png

[Neven]

CT SIA has been updated. It seems the minimum was reached on September 10th, coming in at 3,554,397 km2.

WRT PDO mechanism: I just realize I wasn't really referring to long-term PDO influence, but perhaps all that warm water in the North Pacific (negative PDO, because of a sliver of relatively cold water along the US and Canada west coast) had an atmospheric influence? I remember reading about that in some paper (2007 Serreze et al.?) in relation to cyclones.

[Chris Reynolds]

Wayne,

I'm not sure what event a month or so ago you are referring to. However CT Area began a second June Cliff, this is visible in the plot that follows from 16 July.
http://farm6.staticflickr.com/5547/9656563816_98cc9ed272_o.png
As with the early June cliff this was most likely due to spread of melt ponding - the prime way of generating large drops in CT Area. Then from 21 July temperatures dropped with the establishment of low pressure. I initially interpreted the rise in CT Area but was persuaded over at the forum that I was wrong.

NCEP/NCAR doesn't show the drop in temperature but the CRREL mass balance buoys do show it.
http://imb.crrel.usace.army.mil/irid_data/2012G_temp.png
http://imb.crrel.usace.army.mil/irid_data/2012H_temp.png
The drop is more apparent in the numeric data rather than those graphs, it was small but enough to take temperatures from typically above zero to typically below.

For Buoy 2012H,
16 to 23 July 0.73degC avg temperature
24 to 29 July -0.41degC avg temperature

For Buoy 2012G,
16 to 23 July 0.62degC avg temperature
24 to 29 July -0.30degC avg temperature

This temperature drop is small but is enough for melt ponds to freeze over. And surface refreeze is a more tenable explanation than CT area being 'tricked' by pack divergence under the low pressure that dominated in the second period listed above (the first period was dominated by a dipole). One could appreciate extent registering an increase of ice with pack divergence, but not area.

[Lars Boelen]

Can we have a big round of applause for Neven for guiding us through this very interesting melt season? Thanks a lot for all your effort!

As they say in Wallstreet, go away in September, but remember to return in March, (or something like that)

[Neven]

Thanks, Lars! I'm going to try and do a post-season analysis before the month is out, and then it's time to practice hibernation again.

[Watkin M]

Hi. Would also like to say thxs to Neven. Have learned such a lot this summer.

I posted a while ago about the fracturing "event" which caused much of the ice to the north of Ellesmere Island and Greenland to break up in mid to late August. The sky was cloudier last year, so hard to compare exact dates, but there is no sign on MODIS of anything of the same magnitude occurring in 2012.

Chris R has very helpfully posted a link to detailed PIOMASS thickness map for May, which shows (I think - the colours are tricky) that the ice in this area was very much thinner this year at the start of the melt season. This presumably explains why the ice broke up despite the weather being less favourable for melt. I am guessing the ice was thin in the spring because of record melting last year.

MODIS is now showing a wide lead (up to 10km) running from the Beaufort Sea, interrupted only by patches of broken ice, all the way to the Fram Strait. Interesting this lead runs precisely through the area which PIOMASS shows with a maximum negative anomaly in May.

Although its been developing for weeks, opening and closing and sometimes filling with "rubble", over the last few days it's opened considerably in several sections. You have to view MODIS over several days to see the entire length of the lead as the area is quite cloudy at the moment. You can see the effect quite clearly to the north of Greenland in the images from the 10th and 12th.

It now appears, and this is the reason for my post, that the ice "cap", or what's left of it, is now structurally detached from the remaining fast ice.

I am wondering if this might be significant - or unprecedented? Would appreciate it if anyone can point me towards pictures comparable to Worldview for years before 2012.

Would also be interested to know if anyone has an explanation. Maybe I'm imagining things, but its almost as if a million+ sqm of ice has simply upped and moved north. I understand the principle of compaction, but its not obvious to me that wind has been blowing in the right direction - not over such a distance - and not strongly either. And surely the prevailing current is onshore?

[Watkin M]

Maybe it was just a fleet of icebreakers?

[jdallen_wa]

Watkins M, I hope you are joking... It would take more icebreakers by an order of magnitude than are currently afloat to do that.

[Watkin M]

Indeed. lol.

[Twemoran]

Watkin M
Are you familiar with the split zoom feature at Actic.io? Flipping back through previous years is simplicity itself.
Terry

[LRC]

"NLPatents - Because Boulder is under water:" Very seriously under water. Tonights news said army equating it to what happened with Katrina. It is a low full of water trapped by stationary fronts and is just sitting there drowning Boulder. It cannot lose its moister because it keeps on getting replenished from the Gulf. So we have to wait until the fronts move on. Then the clean up begins and depending on how bad and how much money and resources are put in it could be a very long time.

[NJSnowFan]

Neven, You care to comment on this

Antarctica has set All time sea ice record extent on September 14 2013.

[What goes on with sea ice at the South Pole is very interesting in its own right (due to big differences between Arctic and Antarctic, situations are difficult to compare), but back in 1992 a modelling study already showed that Antarctic sea ice would likely expand under a warming scenario. Research into the exact reasons for the expansion is ongoing. Most factors are known, but not how much influence each has. I personally think it's a combination of changing winds and run-off fresh water from land ice; N.]

[jdallen_wa]

@NJSnowFan - Hmmm, trolling?

Might start looking here for why - had a new Maximum last year.

http://earthobservatory.nasa.gov/IOTD/view.php?id=79369

I'd say this is very interesting climatologically as well:

http://scienceblog.com/66290/south-pole-experiences-more-record-heat-in-august-to-end-warmest-winter-ever/

In short, the extent reference you are making is no indication of a slow down in climate change.

[wayne]

Chris, area is surely the better stat, but consider this, compaction ridges the ice as opposed to a thin very large spread , nature of minima 2012 is not at all the same as 2013. A layer 50 cm thick is considered the same as 150. As said by Werther there was rubble pancake ice for about 2 million square km. Squeeze this ice together by 50% and you have a total area of 2.5 million km2. Same number or less than 2012. BTW Thanks for the discussion , it sharpens my focus, the 15% threshold for area and extent still baffles me. Why not no threshold at all?

AMSR2 map still shows a cooler pack image, -11 has been exceeded in many parts within the "cold" Arctic area. Freezing has started there.

[NJSnowFan]

Jadelan, no, not trolling. Ot. Question was for Neven. Cyosphere chart shows No record for S Hem.
Interesting about the temperature at S pole station. Now that is for one location of more then 20 stations or so and not for All of Antarctica right? I would like to see how All of the stations around Antarctica did on average. Cold spread out to create such an ice extent.