Friday, 3 February 2012

Halley 6 - part 2 Cabooses.

Much of the science at Halley comes from equipment situated in shipping containers that we call cabooses. This one is the Superdarn caboose:

Superdarn is a big radar that looks out over a large part of Antarctica, measuring the position and velocity of charged particles in the Earth's ionosphere, the highest layer of the Earth's atmosphere, which tells scientists about the Earth's interaction with the space environment. Another Caboose we have is the Optical caboose, it contains experiments that look at optical phenomena such as the aurora.

Halley gets a lot of aurora - of course you can only see them in the winter, now its summer with 24 hour daylight and we can't see them - here's a picture of aurora taken at Halley in winter.

You will notice that the optical caboose looks remarkably similar to the Superdarn radar caboose, in fact we have five cabooses that all look very similar - although they are all customised for their particular function. The advantage of running science from cabooses is that they can all be positioned in the ideal place compared to the rest of the stuff around the station. So for instance the optical caboose is over a km from the main station to guarantee that it is very dark, the radars are a km in a different direction so that the large radio pulses they send out don't interfere with the sensitive experiments that are in another caboose over 2 km away in the other direction.

You might be wondering why the cabooses are yellow. Well they are very heavily insulated to minimise energy use in winter when they need to be heated, but in summer when the temperatures are warmer we tend to need to cool the electronics inside, if the cabooses were a dark colour then they would absorb lots of heat from the sunshine and would be difficult to keep cool. Ideally we would paint them white to keep them cool, we tried this once but white cabooses are too hard to see against the snow. This particular shade of yellow doesn't heat up much in the sunshine and is easy to see in both sunny and bad weather conditions.

Inside the cabooses look like a crowded science lab, full of electronics and computers. Here I am inside the optical caboose.

Here is DJ inside a caboose that we call the EMQA caboose - that stands for ElectroMagnetic Quiet Area, it's where we run the sensitive scientific radio receivers from.

And here's Ollie and Neil inside the MFradar caboose - that's another radar - this one measures the wind in the atmosphere from 40km to 100km up.

How many times did you see Penny?


  1. I saw penny 3 times

  2. so how does radar work to detect changes in the atmosphere, i thought it had to 'bounce off' solid objects in the sky like airplanes etc. is it reflected off charged particles?

    1. In some ways it's harder to explain why radio waves bounce off metal than why they bounce of bits of the atmosphere! Radio waves are just like light except that they have longer wavelength, just like light the path of a ray is changed by gradients in refractive index - charged particles change the refractive index of the atmosphere and hence you can get returned power from hitting them with a pulse of radio waves at the right wavelength. With the right wavelengths you can also get echoes from the density gradients caused by turbulence.

  3. How many cabooses are there in total at hally?

  4. There are five science laboratory cabooses, there also a very similar structure on legs that we use to launch the daily meteorological balloon from. In addition there are three travelling cabooses which are containers on skis which give accommodation away from the station - a bit like Antarctic caravans! So in total that makes nine!

  5. Yellow looks nicer than the old red cabooses at Halley that used to heat up