319 replies to this topic

[BornFromTheVoid]

Cryosphere Today has updated, and we now have a new sea ice area maximum of 13.701m as of day 78 (March 18th?)

http://arctic.atmos....nteractive.html

[Gray-Wolf]

Last years 'late' max should be a warning to us all (not that it made a blind bit of difference to the season?). I'm aware of a lot of thin peripheral ice (like last year?( so the drop off into June will be fun? Should lead to a few posters falling silent for the duration?

[4wd]

Gray-Wolf, on 22 March 2012 - 22:53 , said:

Should lead to a few posters falling silent for the duration?

No doubt you'll be here rushing out daily reports (whenever there's a few warm days anyhow)
Then about the start of August it will be clear nothing untoward is happening for yet another year and it will suddenly go quiet

[Geordiesnow]

Gray-Wolf, on 22 March 2012 - 22:53 , said:

Last years 'late' max should be a warning to us all (not that it made a blind bit of difference to the season?). I'm aware of a lot of thin peripheral ice (like last year?( so the drop off into June will be fun? Should lead to a few posters falling silent for the duration?

Do you mean 2010 GW? Last year max came on the 7th March according to NSIDC but the extent was fairly steady during March if albeit way below average and below this years extent for March thus far.

I still think we could be near or at record lows by the end of Spring because of the amount of thin ice in the Kara Sea and Barants Sea area which will probably melt out if any warmer weather threatens just for a few days as we go through Spring but from then on in, it will be down to what weather patterns across the Arctic this summer which will determine what the final extent will be.

[BornFromTheVoid]

Cryosphere today has updated and I think we can call the maximum now as the 18th of March, unless we end up with the 2nd latest maximum on record.

Condition look like remaining quite good for the next week, despite hints of the ol' dipole pattern returning. 850s remain low over the main peripheral ice areas and the central Arctic, so some gains in Kara and Barents should continue. As is the case with this time of year though, sea ice reductions overall should still be expected, but I'd expect them to be minor for now and not too far off average.

T0
SLP & 850hPa


T96
SLP & 850hPa


T168
SLP & 850hPa

[BornFromTheVoid]

Here's a short animation from the last week over the Bering Strait showing the sea ice in the Chukchi sea breaking up. The images used are from MODIS http://lance.nasa.go...rapid-response/
it looks much more clear when viewed full size. I just used cropped screen shots so not every image is exactly the same size...



EDIT: I realise I didn't give much of an idea of scale for the animation. Here's roughly the area represented above

Edited by BornFromTheVoid, 26 March 2012 - 20:18 .

[paul tall]

Gray-Wolf, on 21 March 2012 - 08:46 , said:

I'd suggest we had record low 'volumes' in 09',10, and 11?

Would you?

Is this scientifically proven fact?

[BornFromTheVoid]

paul tall, on 26 March 2012 - 19:36 , said:

Would you?

Is this scientifically proven fact?

Here's one sea ice volume anomaly chart anyway



Lots more volume data here https://sites.google...uin/home/piomas

[paul tall]

So is it fact then that 09, 10, and 11 had record low volumes?

[BornFromTheVoid]

I'm not really saying anything is fact. Just giving you some data to draw your own conclusions from.
In my opinion on the other hand, based on the data, I'd say out of the 3 years, just '10 and '11 had record low sea ice volumes.

[4wd]

There isn't any real measurement of volume, The Piomas graph is estimated.
Their fondness of exponential extrapolation is unrealistic and suggests a campaigning agenda.
https://sites.google...iomas-trnd2.png

[Gray-Wolf]

OK Guy's, how's about what was more likely in 09/10/11 Record high volume/extent or record low?

We are busy watching our way through to a seasonal pack and yet we still have folk playing the pedant??? Where does this type of behavior leave us? I , for one, shall not entertain such anymore. Arctic sea ice /the Arctic Basin is undergoing changes that we have not seen in the geologic record for tens of thousands of years...end of?

[laserguy]

Gray-Wolf, on 27 March 2012 - 09:02 , said:

I , for one, shall not entertain such anymore.

I always find you entertaining GW,intentional or otherwise!

[BornFromTheVoid]

4wd, on 27 March 2012 - 07:41 , said:

There isn't any real measurement of volume, The Piomas graph is estimated.
Their fondness of exponential extrapolation is unrealistic and suggests a campaigning agenda.
https://sites.google...iomas-trnd2.png

Some info on their validation process

Quote

PIOMAS has been extensively validated through comparisons with observations from US-Navy submarines, oceanographic moorings, and satellites. In addition model runs were performed in which model parameters and assimilation procedures were altered. From these validation studies we arrive at conservative estimates of the uncertainty in the trend of ± 1.0 10³ km³/decade. The uncertainty of the monthly averaged ice volume anomaly is estimated as ±0.75 10³ km³. Total volume uncertainties are larger than those for the anomaly because model biases are removed when calculating the anomalies. The uncertainty for October total ice volume is estimated to be ±1.35 10³ km³ . Comparison of winter total volumes with other volume estimates need to account for the fact that the PIOMAS domain currently does not extend southward far enough to cover all areas that can have winter time ice cover. Areas in the Sea of Okhotsk and in the Gulf of St. Lawrence are partially excluded from the domain. Details on model validation can be found in Schweiger et al. 2011 and (here). Additional information on PIOMAS can be found (here)

They use a variety of extrapolation methods for the September volume chart, which I guess is the important one.


Doesn't make sense that they would purposely manipulate the data to show 0 volume so soon though, unless that's simply the way the trend is going. Their propaganda campaign must be under funded if seeing as one of the graphs shows zero volume this September!

[jethro]

Gray-Wolf, on 27 March 2012 - 09:02 , said:

OK Guy's, how's about what was more likely in 09/10/11 Record high volume/extent or record low?

We are busy watching our way through to a seasonal pack and yet we still have folk playing the pedant??? Where does this type of behavior leave us? I , for one, shall not entertain such anymore. Arctic sea ice /the Arctic Basin is undergoing changes that we have not seen in the geologic record for tens of thousands of years...end of?

You'd best stick your fingers in your ears then GW; I for one won't be towing the party line in order to keep the ardently pro side of this debate happy.

I wonder, where can I get one of those oh so accurate crystal balls to check out the last tens of thousands of years........Anyone got a spare Tardis?

[Weather Ship]

Just for a change the Arctic midday surface plots and 500mb contours.

Attached Thumbnails

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[songster]

The PIOMAS team don't make any projections whatsoever from their graphs. All those graphs were drawn up by people in the blogosphere, not the scientists actually working on the PIOMAS model. Note also that they were explicitly drawn up as thought exercises, not as formal predictions.

The scientists did however produce a prediction a while back based on running the model forward (not simply extrapolating from graphs). It forecasts a collapse of Arctic ice extent some time in mid 20's - 30's, i.e. a bit ahead of other models, but not drastically so.
http://psc.apl.washi...IDAO/multi.html

[BornFromTheVoid]

The NSIDC have called the maximum now as the 18th

http://nsidc.org/arcticseaicenews/

The sea ice extent has dropped a small bit since then, but has essentially flat lined for the last few days and is still above the 1st of March extent value.
http://nsidc.org/dat..._timeseries.png

[paul tall]

Gray-Wolf, on 27 March 2012 - 09:02 , said:

OK Guy's, how's about what was more likely in 09/10/11 Record high volume/extent or record low?

Does it have to be either? No, no it doesn't.

[Gray-Wolf]

Again, having been brought up around Geology, paleoclimatic records have always scored high in my understanding of my world and how it evolved. The past 10,000yrs (being 'recent' ) are well covered by such and , thanks to oil/gas comp.s, we have good data across the arctic basin.

As such I lean toward our scientific understanding of the 'way' the basin has been over that time and it has not seen so little ice over that time and ,if the records are to be believed, plenty more ice than we see today......and as for what we'll see this Sept? Well, let's wait then it can be a nice surprise?