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1
Consequences / Re: 2015 El NiƱo?
« on: August 09, 2015, 05:27:12 AM »
Per the attached plot issued today by the BoM, the 30-day moving average SOI has dropped down to -19.0:

Do you happen to know what the value was during the 97-98 El Nino?

2
I keep reminding myself that 2011 was more or less a return to the 2007 low and that preconditioned the ice for the new record low in 2012.  2015 is much like 2011 IMO, right now the trace for ice Area on CT is closely paralleling 2007/2011.  Even if nothing else goes wrong we are looking at a low remaining ice year, and couple that with the El Nino going on through this winter and we might have a new massive loss record year 2016.

3
Arctic sea ice / Re: The 2015 melting season
« on: August 06, 2015, 03:07:18 AM »
Personally I'd like to compare these two too.

The Maslanik/Fowler/Tschudi ice age map in May on which a lot of the volume and end season extent area predictions were made.



Yesterday's Bremen visual map zoomed into the Beaufort and Banks island.



Now unless my eyes deceive me, that huge nexus of red 5m+ ice off Banks Island and Ellesmere island seems to be either gone or vanishing at an increasing rate.

Neil here is a more recent sea ice age map off the graph page Neven put up.
http://ftp://ccar.colorado.edu/pub/tschudi/iceage/gifs/age2015_27.gif

4
Arctic sea ice / Re: The 2015 melting season
« on: August 05, 2015, 04:19:38 PM »
The GLB HYCOM+CICE model seems to have been fixed,

http://www7320.nrlssc.navy.mil/GLBhycomcice1-12/arctic.html



Is this a Sea Surface Salinity map?  If so it is the first I have noticed being posted, how does it compare to say 2006?

5
Looks like a great spot for the next Heartland Conference.  ;)

funny!

Also when the water releases it will scour away the melted mud surface layers and produce significantly increased thaw at all parts down flow (as well as the lake bed.

It isn't just the scouring either, mud flats are much better at soaking up solar energy that leafy green surface cover.  All the area the mud flows over and darkens will be subject to lower albedo, not just the area actually scoured.

6
Do the tabular bergs that break off of Petermann get names like the ones that form in Antarctica from the ice shelves there?

7
Science / Re: A Looming Climate Shift??
« on: August 02, 2015, 08:47:29 PM »
It all works the same whether you call it a bifurcated function or a tipping point.  Either way at some unknown threshold you switch from one mode of climate to the other mode.

A lecture I watched from a mathematician on the topic stated that one sign of a tipping point was wild swings in the tracked variables at the critical threshold, then everything calmed down afterwards in the new stable relationships. 

<snip>

For the switch from three cells to one cell it will be the same way, we will sooner or later dump enough CO2, NOx and CH4 into the atmosphere and suddenly we will go from what was to what is to be.

The key quote is "wild swings in the tracked variables". What is the tracked variables in the case of the three cells? Latitudinal extent? Total air momentum? And do we have any good online resources tracking those variables for each cell?

Another interesting question: How are the amplitude and frequency of the swings, related to time line of an eventual coming shift?

Well Dr. Francis is tracking the amplitude of the Rossby waves as well as the temperature differential on each side.  If I understood the ppt presentation linked to above correctly, so long as there is a large temperature differential between the Polar and Temperate cells we will maintain the three cell configuration.  However the smaller the temperature difference between the two sides of the cell boundary the more likely the boundary is to break up and merge into one uniform cell.  Some year or other we will end up with temperatures going into sync between the Temperate and Polar cell and then we will have the very unstable two cell system with Tropical on one side and Temperate on the other.  With the polar and Temperate merged together a great deal of heat from the Temperate zone would be dumped into the Polar region.  After months or years of that kind of heat transport the boundary between Temperate and Tropical zones breaks down and Viole' one cell takes over as the climate function. 

I think because of the amount of energy input needed you would probably see the Polar/Temperate cells merge in September of one year and then with the Temperate zone feeding energy up to the Polar zone all winter the next year you would start with very little ice in the Arctic Ocean allowing the sea to absorb sunlight rapidly due to low albedo.  From late May to late July the solar isolation in the Polar zone is higher than it is at the equator.  The only reason Polar summer is so cool is all the albedo effect rejecting the sunlight.  Take away the albedo and the pole will get very warm very quickly from the 24/7 high isolation situation.

Once the Arctic warms up that much be it one summer or several the temperature difference between the pole and equator will disappear and a single cell will form.  Once we collapse from three cells to one cell the climate will stabilize again, sub tropical all the way from Equator to the Arctic Circle and temperate from there to the pole.




8
Science / Re: A Looming Climate Shift??
« on: August 02, 2015, 06:48:08 AM »
It all works the same whether you call it a bifurcated function or a tipping point.  Either way at some unknown threshold you switch from one mode of climate to the other mode.

A lecture I watched from a mathematician on the topic stated that one sign of a tipping point was wild swings in the tracked variables at the critical threshold, then everything calmed down afterwards in the new stable relationships.  The example used was a clear healthy pond with diverse ecosystems being turned into a turbid partially anoxic ecosystem that only supported a very small range of species adapted to those conditions.  In the example farm runoff of nitrogen fertilizers caused algal blooms that rotted quickly consuming most of the oxygen dissolved in the water.

For the switch from three cells to one cell it will be the same way, we will sooner or later dump enough CO2, NOx and CH4 into the atmosphere and suddenly we will go from what was to what is to be.

9
Arctic sea ice / Re: 2015 sea ice area and extent data
« on: August 02, 2015, 05:32:36 AM »
As I understand it the cold fresh melt water is more buoyant than the salt water just beneath it so in calm conditions it floats on top and spread out in a very thin layer until mixing in and effectively dissipating.  However when high winds or stormy weather mixes things up the fresh melt water is quickly mixed into the saltier water just below dissipating it quickly.

Is this an accurate picture of how the mixing process works?

If so does the mixing slow down the formation of first year ice by removing the easily frozen fresh water from the surface layer?

TIA

10
ATTENTION: There are two polls on the ASIF. One is for NSIDC sea ice extent monthly/September average minimum, the other is for Cryosphere Today sea ice area daily minimum. Make sure you are aware of the difference before voting. You can discuss various extent/area data sets in this dedicated thread.

-----

This NSIDC extent poll will run for 12 days (until August 13th). Until then you can change your vote. This is this year's last poll.

Here's how things are currently looking based on data up to July 30th:

These are the September minimums for the last 8 years (in millions km2, found here):

    2005: 5.57
    2006: 5.92
    2007: 4.30
    2008: 4.73
    2009: 5.39
    2010: 4.93
    2011: 4.63
    2012: 3.63
    2013: 5.35
    2014: 5.28

You can use the comment thread below to motivate your choice, but discuss various SIE/SIA data sets in this dedicated thread.

Neven FYI the link you included took me to the 2014 dedicated thread instead of the 2015 dedicated thread.

11
I went up 1.5 million km^2 from my vote in March.  I look at the pattern for the last month now and it feels a lot like 2007/2011 will be repeated to me.

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