3D Data and the Dipstick

One way of working with data which has a spatial or geographic context is to figure out a way of plotting it on Google Earth.  Apart from the provision of maps, Google Earth takes care of all the maths needed to display 3D data which can reduce the task  to generating a .kml file with the data to be displayed.

Whilst techniques such as correlation are useful, displaying two or more variables graphically can provide an insight into data which might not be obvious on a graph or from a table of numbers.  Recently, I have had to look at some atmospheric data obtained from GFS (see note below), in addition to latitude and longitude, some elements of this have a vertical component defined by the pressure level (e.g. 900 mb).  The example below shows relative humidity around noon for a randomly selected day in June 2015.

For lack of a better name, this graphic device has been called a dipstick.  In terms of kml, each dipstick is a series of linestrings, the colour of which is determined by the value of the data value.  In this example, the colour scheme has been taken from ColorBrewer.  A vertical exaggeration of 5.0 has been applied, some experimentation is needed to find a value which is appropriated for the data and the geographic scope.

I'm far from being an expert on weather data, but my understanding is that clouds form when the relative humidity is high, this example suggests clear skies over the south east of England with low to medium cloud to the north.

GFS is the Global Forecast System, extensive datasets from which are made available by NOAA.  I would like to express my appreciation as these are a valuable learning resource.

I believe this representation to be original, any plagiarism is unintentional.

Water Metering - A brief (and personal) history

The great thing about the internet is that you can find a large lump of iron whilst walking the dog and an hour later history unfolds.  I found this object whilst following my dog into some bushes to prevent him doing something regrettable.

It is probably a water meter which was made by Glenfield and Kennedy in Kilmarnock, the location suggests that it might have been installed around 1910 (a guess).  It seems that water passing through the device causes a reciprocating motion of a piston in a cylinder, a mechanism records the number of oscilations and this is scaled to indicate the cumulative water flow.  At a guess the maximum flow rate was not high (the piping seems to be 1/2 inch internal diameter) and there would have been a noticable pressure drop across the meter.  Maybe the occupants of the building were not too keen on bathing.

A few years back, the water company moved us onto a metered supply in place of a fixed tariff.  The meter appears to use a small turbine and does not appear to drop the pressure of restrict the flow rate.

When it was announced that water meters were going to be installed, there were two reactions, the first was that bills were going to increase and secondly that a restriction on consumption was an infringement of liberty.  Our own bill fell, this may not have been the case if all our children were still living at home, also we only use rain water on the garden.  The second one has faded, but is a recurring theme.

Whilst I am interested in sustainability, I am not convinced that price and enforced constraint are effective tools for managing consumption.  In theory, increasing resource prices should reduce consumption, however, the energy is inelastic, which is an economist's way of saying that a big increase in price does not result in a big drop in consumption. Those on low incomes resent high prices (children have to be washed and petrol may be needed to get to work) and those on high ones don't care.  To complicate matters, the business model of energy companies is based on selling more product, although there seems to be increasing competition for market share.  Changing this is a big challenge, one possibility is to move to a system which is based on the benefits of water, energy etc. rather than the volume supplied.