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If it was not clear, I was replying to Al Rodger "is this year's timing the result of a super icy February, a seriously melty March, or is it a combination of the two?"
Early record, late record
10 days ago I posted a blog post called Mad max. The title - referring to a very early maximum sea ice extent - ended with a question mark, because it was far from sure whether the preliminary max reached on February 15th would remain standing. This is because of the oscillatory nature of the f...
I'd have to put it down to stable stratospheric conditions and a cloudy winter. There has not been the 'clear skies' that result from a large stratospheric warming event. There has also been a lack of spreading events so far this 'spring'.
Speaking of stratospheric warming, here's NOAA's 50hpa temp anomaly animation showing one just getting underway in the NH. http://www.cpc.ncep.noaa.gov/products/intraseasonal/temp50anim.gif
Early record, late record
10 days ago I posted a blog post called Mad max. The title - referring to a very early maximum sea ice extent - ended with a question mark, because it was far from sure whether the preliminary max reached on February 15th would remain standing. This is because of the oscillatory nature of the f...
As the dmi arctic weather link shows, these cyclones are helped along by a large (20º+) temperature difference between the pole and surrounding area.
The geo-potential height shows a pool of upper cold air hanging over the arctic (and virtually nowhere else).
What I'm wondering is how this situation has been maintained all summer, and why doesn't it break down?
One factor would appear to be the clouds are keeping things cooler, thus maintaining the temperature imbalance and promoting more cyclones which bring yet more clouds.
It would also appear that the jet stream is acting to 'cut-off' the upper atmosphere over the high arctic from the rest of the NH.
(Could the Stratospheric warming earlier this season have impacted this pattern?)
But that still leaves the question - what is happening to all the warm air-masses flowing into the arctic (for example the warm front above), where is that heat going?
Third storm
Are we getting used to this? After the persistent cyclone in May and June, and the spiffy, but short-lived cyclone of two weeks ago, the Arctic is visited by yet another intense storm that goes below 980 hPa. In fact, according to Environment Canada it is currently at 976 hPa, which is lower tha...
3.8±0.2
Based on melt-favouring weather, that central 'hole' melting out, and some compaction at the end of the season.
Surprises may be on the up-side, but I will be very surprised if the minimum is not lower than 2007.
I would consider this a low-skill prediction - I have learned much from this blog and other sources over the years since 2007, but by no means am an expert.
Crowd-Source Prediction of September Sea Ice Extent (July report & call for August predictions)
In mid-June through early July, participants on the Arctic Sea Ice (ASI) blog posted 82 individual predictions for the mean NSIDC September Arctic sea ice extent. The median value of these 82 predictions was 3.2 million km2, with an interquartile range (approximately the middle 50% of prediction...
Great post as always, Seems with the recent weather prediction, what was looking like a 2013 recovery is 'on thin ice'.
I note that the relatively 'warm' conditions in Antarctica are continuing, wonder if this will have any effect on the WAIS down the track?
ASI 2013 update 4: bye bye, Beaufort
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 Cryosphere Today sea ice area (SIA) and IJIS sea ice extent (SIE) numbers, which I compare to data from the 2005-2012 period (NSIDC has ...
I notice something strange in the concentration map here
ftp://ftp-projects.zmaw.de/seaice/AMSR2/
Arc_latest_yesterday_AMSR2_3.125km.png
There seems to be a 'reflection' of the CAA land mask in the Ice cover on the 'opposite' side of the Arctic. I'm assuming its an image processing problem.
Kevin: seems like a reversal of the 'warm arctic cold continents' pattern.
So, how slow was this start?
It's half time in the Arctic, and with the Summer Solstice and the first half of the melting season behind us, it's time for an assessment. It's clear that PAC-2013, this year's persistent Arctic cyclone, kept the Arctic in a cold and cloudy grip, causing a very slow start to the melting seaso...
A little off topic,
Catalyst, a science program from the ABC in Australia,
has done a nice little segment on the effects of the warming climate and melting sea ice on the weather.
http://www.abc.net.au/catalyst/stories/3796205.htm
Now back on topic. "Why is the ice then diverging below a low-pressure cyclone?" You can think of it this way.
Because the earth is rotating counter-clockwise about the north pole, the Ice is also rotating. So it is subject to centrifugal force.
The Low (because of the counter-clockwise winds) is acting to speed up the Ice, thereby creating more centrifugal force, hence greater divergence.
The High acts as a 'brake' on the ice, reducing the centrifugal force, and making the ice more compact.
philiponfire: I See what you mean about the NW passage, it looks rather - blue. Doubt that ice has much time left.
So, how slow was this start?
It's half time in the Arctic, and with the Summer Solstice and the first half of the melting season behind us, it's time for an assessment. It's clear that PAC-2013, this year's persistent Arctic cyclone, kept the Arctic in a cold and cloudy grip, causing a very slow start to the melting seaso...
Thought I might give the view on this from 'down-under'
(or the south-east corner at least).
After the crippling drought - which brought with it Stage-4 water restrictions in many areas, and serious impact on the murray-darling system - broke in 2010, support for Co2 reduction measures fell sharply. [This was also helped by major campaign by big business, and almost all privately owned media against the carbon tax].
There is a general consensus among the population that Greenhouse gas emissions are a problem, and awareness (if somewhat vague) that the arctic is melting because of them.
- from the NW Passage opening, and 2007 ice loss reports if nothing else.
But the arctic is far away from us, and the line pushed by the media is that Australia is too small to make a difference if it acts alone, and with other major emitters (read the USA and China, in that order) not pulling their weight, all we will be doing is 'pointlessly putting our economy at disadvantage' to those countries.
What is not reported here is the other changes happening in the Northern Hemisphere - Such as those of atmospheric circulation patterns. When I mention these kind of changes eg. the shift north in the sub-tropical boundary, change in location of cyclones and anti-cyclones and frequent flooding in the UK, are quite likely the result of climate change and melting arctic sea ice, the reaction is wow!
If someone were to make something along the lines of 'inconvenient truth' but instead spell out what has been happening over the past decade (when fake sceptics say 'global warming paused / stopped') - or local media was to do a decent report on it - That would have a great impact here right now, particularly coming after a rather warm summer and an highly unusual March (early Autumn) heat-wave.
The only thing that would have greater impact on policy is for the USA to stop dragging their feet, as that is the most common excuse for doing next to nothing about it.
Perception of the Arctic
There was a time, not too long ago, when I didn't know the Arctic existed. Sure, I knew there was a North Pole and that it was cold there, but somehow I always thought that the Arctic and the Antarctic were the same thing, that someone had forgotten to add the Ant-. And of course, polar bears ...
* while the cooling stratosphere has caused the antarctic vortex to speed up, and the circum-polar lows to move south
The bunny explains
It started one and a half year ago with the suspension of Arctic scientist Charles Monnett, which quickly turned out to be a Kafkaesque witch hunt. It is becoming increasingly clear that the 'investigation' was fuelled by fossil fuel, and the person that explains the whole saga best is none othe...
A-Team:
Australia is an interesting case,
The North is expecting more rain thanks in part to the 'Asian Brown Cloud' (local dimming in SE Asian region), while the cooling stratosphere has caused the antarctic vortex to speed up the circum-polar lows to move south, making southern parts of the continent much more prone to drought.
Neven:
Events like Yasi are much more likely during La Nina years, so it depends on how warming affects ENSO.
The bunny explains
It started one and a half year ago with the suspension of Arctic scientist Charles Monnett, which quickly turned out to be a Kafkaesque witch hunt. It is becoming increasingly clear that the 'investigation' was fuelled by fossil fuel, and the person that explains the whole saga best is none othe...
Comparing the areas of ice, and land to the DMI map above, Seems that the lows 'want' to sit over the 'warm' / convection favouring open water, while the highs are sitting on the cold ice and continents. This would tend to be a self-reinforcing situation. Whats interesting is how 'skewed' the polar cell is. It almost looks like there are just two cells over the US, a tropical cell, and a polar cell.
I wonder if, when the ice melts out completely, we will see a new atmospheric circulation system develop with a low over the polar sea, and highs over the surrounding continents. This might have the effect of keeping the arctic cloudy and relatively ice-free over the winter.
Looking for winter weirdness
The Arctic is refreezing fast. Trend lines that were way below all other years for weeks on end have returned to the pack, as can be seen on the Daily graphs page of the Arctic Sea Ice Graphs website. Of course, there's still much more open water now than during the long-term average, and so we ...
That's a worry, was hoping that the cold stratosphere, and the antarctic vortex would keep the south pole a bit isolated from the warming climate. If we have to take serious warming in the south, as well as the north into account, then sea level rise gets that bit more serious.
What role did the Arctic storm play in the record sea ice minimum?
There's another good piece on SkepticalScience that analyzes the past melting season (Tamino is on a roll as well with Arctic air temperatures, here and here). Here's an excerpt: While the 2012 Arctic storm was a strong one, as Newman noted, it was not unprecedented. To confirm Newman's claim,...
Negative AO will favour 'cut-off' systems, the question is does the lack and/or distribution of sea ice encourage the negative AO?
Looking for winter weirdness
The Arctic is refreezing fast. Trend lines that were way below all other years for weeks on end have returned to the pack, as can be seen on the Daily graphs page of the Arctic Sea Ice Graphs website. Of course, there's still much more open water now than during the long-term average, and so we ...
When I first saw that mslp chart, my thought was 'that makes no sense'. But obviously things are a bit different in the Northern Hemisphere.
in Australia this kind of system would be an 'east-coast low'.
Here it can be seen tracking along the coast, and maintaining the high pressure 'wall'
http://www.ecmwf.int/products/forecasts/d/charts/medium/deterministic/msl_uv850_z500!Wind%20850%20and%20mslp!72!North%20America!pop!od!oper!public_plots!2012102700!!/ Upper level conditions also look quite favourable for it to maintain strength.
Looking for winter weirdness
The Arctic is refreezing fast. Trend lines that were way below all other years for weeks on end have returned to the pack, as can be seen on the Daily graphs page of the Arctic Sea Ice Graphs website. Of course, there's still much more open water now than during the long-term average, and so we ...
Latest CT area just under 2.24M sq.Km! would have hoped for some re-freeze by now.
Sea ice loss 2012: what do the records mean?
A lot of good stuff coming out lately. First of all this one hour programme on Radio Ecoshock with Jennifer Francis, Mark Serreze and Cecilia Bitz, which I highly recommend, especially the first interview with Dr. Jennifer Francis: Arctic Meltdown, Scientists Speak Out For the people who weren't...
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