Albemarle 2

This post being an attempt to capture some of the talk given by Dame Julia Slingo, introduced on the previous post.

We started off with some very old maps of ocean currents, perhaps from the seventeenth century.

From there we moved to the invention of the Meteorological Office of India in the nineteenth century, the thought being that if we got a better grip on the weather, we might do a better job of mitigating the regular famines. Dame Julia explained that the timing of the monsoons was all important, and was still something that we had not got taped down yet, despite it having been one of her own specialities.

Onto to the Coriolis force, all about the preservation of angular momentum as winds blow around the earth. The explanation on the day was a bit fast for me, but wikipedia plugged the gap.

Then a nice diagram showing the jet stream over the North Pole, which seemed to exhibit a sequence of near stabilities. We we had pictures which throbbed & wobbled a bit, but which held their gross structure for a bit, before moving onto the next structure, the next cycle.

Next up a diagram explaining how the green house effect worked: too much solar radiation in and not enough thermal radiation out. It seems that the basic arithmetic of all this has been known for a long time, with the basic linear relationship between total carbon burn to date and increase in temperature holding very steady. Asking google for images for 'greenhouse effect' gives one plenty of the same sort of thing.

Then some nice visuals of clouds swirling around the globe, one particularly effective one showing clouds projected onto a mercator map of the globe and speeded up to a day every few seconds. The snip above taken from reference 2 is not the same, but it does give some idea.

She explained that most climate models worked by dividing the domain into lots of chunks, small bricks if you will, defining a starting position, writing the rules which say how to move the thing forward, that is to say how, given the state of the brick and its neighbours, to move the first brick from time 1 to time 2 - and then just cranking the handle. In this it was important to integrate the air, sea and land systems; they were inter-related and modelling one in isolation was not the way forward, not for climate research anyway. Note the way the sea and land systems bring in all kinds of boundary conditions, conditions of a sort not experienced by an isolated air system.

She went on to explain that while we had become quite good at simulating weather and climate, forecasting if you prefer, we were not yet good enough. Our models, such as they were, were computer bound rather than data bound, and so the way to progress was to buy them an even bigger and better computer so that they can drop down from 100km squares to 10km squares - or even smaller. Sadly while I am clear about the desire for a bigger and better computer, I am vague about the squares business - with wikipedia adding more detail than I can easily digest. And I have no idea how the size of the computer they want compares to that of those which, for example, support our own nuclear weapons program or the LHC over in Europe.

But I am clear that big bricks or big squares, however cleverly you write the equations describing their behaviour, are apt to smooth things out. Smooth things out to the point where small beginnings which might lead to bigger things are apt to get lost. I associate to the butterfly flapping in the China Sea giving rise, some time later, to a hurricane in the Caribbean. Or some squiggle in the roaring forties tweaking the timing of the sub-continental monsoon.

It was also very clear that global warming is happening, with the temperature rise set to be somewhere in the 2-4 degrees celsius range. Which, from what I recall of the Stern report, would be enough to trigger migrations from the regions worst affected on a scale which would dwarf those which are troubling us just presently.

There was something of a postcript on sunspots, with the sunspot cycle perhaps being about to enter the phase when solar radiation was low, in fact the lowest for some time. The story on this occasion was that while sunspots might indeed help with global warming, they were not going to help enough. With one feature of sunspots being that small changes in radiation from the sun could make bigger changes in climate than one might have expected from the older, coarser models. I wonder how much of all this Piers Corbyn, the brother of our favourite crow and something of an expert on both weather and sunspots, would agree with.

Coming away, it struck me that some of this probably copies across to modelling the activity of neurons in the human brain. Modelling in big bricks might give one the general idea, but maybe all kinds of important detail is going to get lost. And maybe the brain also exhibits the sort of near stabilities mentioned at the beginning; maybe each half second frame of consciousness is one such.

Reference 1: https://en.wikipedia.org/wiki/Coriolis_force.

Reference 2: https://www.vets.ucar.edu/vg/T341/index.shtml.