This passionate posting over at Daily Kos caught my attention.  So I’m trying to understand the  fundamentals  a bit more and ignore the passion.  The first image shows a warm current of ocean water sweeping up the west coast of Greenland.  The posting suggests this is tied up in the recent snows in England and makes the usual suggestive tie to global warming.  All in all it made me curious.

This first map shows the major currents of the North Atlantic.  If you look at the eastern sea board of the US you’ll see the gulf stream, in warm red, flowing up the coast.  Below that a cold blue stream of water flows south.  The Gulf stream begins life in the Gulf of Mexico, while the cold current begins along the coast of  Labrador.

You’ll notice that the Gulf stream pumps a lot of warmth into the ocean around England, Iceland, Norway.  The trade wind plays a key role in that.  (Read about the North Atlantic Oscillation to get a feel for the drivers of those trade winds.)    The winds sweep west to east across the seas south of Iceland drawing warmth from the Gulf stream depositing it into British Isles, and Europe.

The second map shows the currents in more detail.  You can see that some of of the gulf splits off and is drawn up around the tip of Greenland and then along up the west coast of Greenland.

These days we have  satellites  that can report on the  temperature  of the sea’s surface, so called SST.  And that can then be plotted either by  temperature SST, or by how much the temp has varied from the usual SSTA. In the alphabet of worry A is for  anomaly.  The third map shows how much the surface temp. is anomalous compared to the seasonal average.  Uou can see the current that wraps the bottom of Greenland is about one degree warmer than usual.  That map is for Jan 6th.  You can keep an eye on it if you want, there are some cool animations there, but not of the anomalies.

But I suspect that this happens when ever they get a serious round of cold weather in Europe.  It does presumably increase the ongoing of glacier retreat along west coast of Greenland.

The nightmare scenario is that the Gulf stream stops warming Europe.  But the story above starts with a cold spell in Europe; not the other way around.  I can build scenarios with positive feedback loops in them using only the above; but they seem pretty  tenuous  and uninformed to me.

I gather that the term ‘Assumption of Generality’ is used in behavioral psychology to highlight the presumption that if our experiments observe a pattern of behavior in one species we are likely to observe that pattern in other species.

For example here is a typcial behaviorist experimental setup.  You put a pigeon in a cage with a button.  If the pigeon pokes the button she get’s a reward.  Then for the next 30 seconds the poking the button doesn’t do anything, but after that another poke gets the pigeon another reward.  In a sense this setup allows us to see if the pigeon has a pocket watch.  A sophisticated pigeon might learn to poke the button exactly every thirty seconds.  What actually happens is the pigeon learns not to poke the button immediately, but as time passes it give it another try, and as the 30 second mark approaches the pigeon starts hitting it more or for frequently.  The rate the pigeon hits the button is said to be scallop shaped; since frequency of pecking rises as the deadline approaches.

If we accept an assumption of generality then we would expect different species placed into a similar experiment to act in a similar manner.  Or to put it another way that they all have similar time keeping skill and  heuristics.  And indeed we do, almost.

Now for years and years I have been a huge fan of practical  behaviorism.    There are plenty of great and useful books on how to use it in everyday life to make things work better and avoid stupid feedback loops with the people around you.  You can find some pretty amazing videos of what people have trained various animals to do.  It’s clear from those that assuming generality has merit.  I had limited success once training a fish, but other people have had amazing success.

But wait a second!  Why had I never heard about the contrarian data about the Assumption of Generality.  Apparently, at least as far as that experiment above, we know that humans, and a few animals, don’t behave in the manner of pigeons.  If you put a human in that experiment they  behave in one of three ways.  You do see the scallop pattern.  You also see to two time other time keeping heuristics.  One is a kind of  rhythmic  pattern, where the animal just hits the button every few seconds.  The second scheme the animal first adopts a mode where he doesn’t hit the button at all, and then switches to a mode where he hits it a lot.

That second scheme is as if the animal takes a walk, knowing that it will be a while before the button works again the animal finds an activity that will provide a reasonable substitute for setting a timer.  This allows him to apply his mind to another activity during the interval.  The rhythmic behavior is similar, he finds something he can use as a metronome and then he can treat the button pushing as a background task.  In both cases the animal has a assembled a more symbolic, or digital time keeping heuristic.

In any case it seems to me  bizarre  that having read over decades discussions of behaviorism and it’s application to problems in various venues that not once did I happen upon the concept of  “Assumption of Generality” and that at least in some scenarios it’s known not to hold.

Stepping back, it’s way common for people to assume that what ever works the systems they are familiar with comprehend drives the other guy’s system.

This is picture of a small portion of my late 19th century house.  This is a bit of the unfinished portion of my attic.  The shot is taken between two of the rafters.

The half inch thick lumber that forms the roof is shown, along with a few roofing nails that have come thru from the other side.  Below you can see the floor of the attic and a small drift of insullation left behind from when it was blown into the side walls.  Somebody, probably the contractor, did the right thing and raked it away from the eves.  At the very bottom you can see into the box that forms the eves.  We had rebuilt some years ago, which is why the wood in there has that coat of white primer on it.

Each year this portion of the room forms a vicious ice dam.  It rains onto the entrance porch and leaves a glaze of ice.  It was the there one of the days the agent showed us the house decades ago.

Ice dams form because the snow on the roof melts. That happens because the roof is warm, it shouldn’t be warm.  The water then flows down till it gets to a cold spot, often the eves, where it freezes.  Maybe you get a dam maybe you just get icicles.  We mostly just get icicles.  That’s good, since if you get damns the water on the warm part sometimes forms pools that work their way thru the roof and damage the interior.  That’s bad because it implies that my eves are being warmed, presumably by warm air traveling up the wall cavities.

Click to Enlarge

I tried to address this problem when we had the roof done and the eves repaired.  The textbooks prescribe that you need to get cold air to flow up the interior surface of the roof.  Entering thru vents in the eves, and exiting thru a vent along the top of the roof.  When we had the roof done a decade ago that’s what we bought.  The eve vents are little one inch holes filled with little aluminum widgets that let the air in and keep the bugs out.

I have another picture like the one above with the lights turned off.  The problem is, it’s entirely black.  No light, and so I presume, no air is getting in from outside.  There are five pairs of rafters in the portion I was inspecting today.  In only one of them is light leaking in.  I feel a slight cold draft in that one, just as I should.

My vacuum cleaner’s hose isn’t long enough to reach into these cavities.  What to do, what to do?

Mimi posts so I don’t have to:  Walk in the Woods.

The mushrooms were excellent.  Lots of single mushrooms, so that was fun.  That collection of logs covered in mushrooms, those are puffballs.  That was the only place we saw a bunch that might have been worth eating; though those were just pass their prime.  And, so far all the puffball’s I’ve tried have been unremarkable, Wonderbread(tm).

As Ike approached landfall last week the National Weather Service warned “Persons not heeding evacuation orders in single-family one- or two-story homes will face certain death.”  I was quite shocked to hear various news sources question that.    Below is a picture of a portion of the Texas shoreline, Gilchrist, Texas on Bolivar Peninsula.  Galveston is south of the channel up to Houston and Bolivar Peninsula is north.  The eye crossed the tip of Bolivar Peninsula and the regions just north-east of there got the worst of it.  I gather 400 people did not to evacuate from the Peninsula.

That photo is one of the set at the Globe’s excellent big picture feature, go look!  Anybody know the address of that house?  I suspect that Google street view and Microsoft Live have pictures of the old neighborhood.

It’s been great weather for mushrooms lately.  Dry the last few days, but yet we found all these on a short walk in our little wooded neighborhood park.

Thanks to my honey for here mosaic mojo!

Someone pointed out that yesterday’s posting had a mistake, the death toll currently stands at 70 thousand, not 20 thousand.  In running down the current report lead me to this graphic.

15 Million people were evacuated!  The entire New York Metropolitian region is 18 Million!

I certainly hope that some large percentage of those will get to go home again if and when the risks of floods is mitigated.