Expert Breakfast Report for 8 August 2018: Prof Craig Rodger, Dept of Physics

We were treated to a fascinating and lively discussion at this breakfast by the Head of the Physics Department.

He gave a short introduction describing himself as a Space Physicist interested in how explosions on the sun affect the space around the earth, and how that can impact our technological systems, such as satellites and power grids. Also, he talked about how those processes that start at the sun can influence earth’s polar atmosphere - “climate change is our fault” he stated,- but there is also natural climate change due to the sun’s activity going on in the background. In order to predict what we are doing to the climate, we also need to understand the natural variability due to the sun also.

Craig was a student at this University for his Honours degree and PhD, did post-doctoral work in the UK, then another post-doc in New Zealand, and was employed on the staff at Otago.
“I’ve lived in the UK, Finland, the USA. I travel extensively for work - I’ve been to Antarctica three times, and the Arctic more times than I can remember.” But, as Prof Rodger explained, it is relatively easy to go to the Arctic, as commercial flights operate there.

Antarctica, Artists and ‘Domestics’ and Dave Dobbyn
Asked about Antarctic visits, Craig explained that, as a scientist, it involved convincing people that you have a contribution to make to the programme. Touching on an experiment involving some radio stations for which he is responsible, he pointed out that it is much cheaper to visit the one in Antarctica than, say, the one in Edmonton, Canada. Also, once you have reached Christchurch, you enter into the Scott Base system, which charges around $70 per day per person, providing the right kind of clothing, food, lodging and transport. There are also plenty of non-scientific opportunities, as they need staff such as plumbers, electricians, chefs and ‘domestics’ who do the laundry, cleaning, etc. Prof Rodger noted that the cold is not as unpleasant as the damp cold we get in Dunedin because the Antarctic air is so dry, so that -1oC in Dunedin is much less comfortable than -20oC in the Antarctic - but this dryness carries with it a risk of dehydration.
There is also an Artists Programme, - “One time when I was there, Dave Dobbyn was down - I spent a lot of time in the bar talking with him.”

The Heroin Problem. Finding a Research Topic and Funds - and Keeping it Going.
In answer to a question about topics for research, he noted that decisions are made on a case-by-case basis. “Generally, it is about having a passion to want to do something you have identified as an interesting research problem.” Academic staff generally are required to do research as part of their job, and this usually, but not always, needs funds from somewhere. His own work is largely theoretical, involving data analysis and modelling, so funding needs are very modest, travel being the most expensive item on the budget. Once you have done enough to prove you can contribute, it is much easier to choose the right funding body and make a successful application. The right funding body might be the Marsden Fund for basic research, but, if your findings might actually be useful, you need to approach a different source. As an example he mentioned some research he was doing whereby events on the sun, in an extreme case, could affect the New Zealand power grid. Initially finding funding was difficult, but eventually a fund for hazard research supplied the money - he postulated that they had some money left over from investigations into volcanoes, earthquakes and tsunamis at the end of their financial year, and he was the ‘lucky’ recipient of a substantial award.

This led him into the tricky area of setting up a project with post-graduates, technical staff, and students and needs to keep it going with the original financing running out. “It’s a little bit like heroin, now I‘ve got to ‘feed the habit’”. New Zealand is a particularly good place for the research he is doing, partly because a large number of measurements have been taken in New Zealand that other countries do not have.

Climate Change, 11 Year Cycle and Skin Cancer
Prof Rodger then addressed a question on the ways the sun can affect earth’s climate. Traditionally there have thought to have been two ways, first being the total amount of energy (Total Solar Radiation Irradiance, or TSIR) arriving from the sun. This used to be considered constant at about 1440 watts per square metre, actually being called the Solar Constant, but has since been found to vary somewhat. Now it has been found that there is a very small 11 year cycle affecting it, amounting to around 0.1% variation. Climate change naysayers claimed for a while that this variation was responsible for climate change rather than human activity. This claim was always rubbish*, and is now widely recognised as such.

While the 11 year cycle is clearly unimportant in climate change where longer light wavelengths are involved, it becomes more significant when one looks at the shorter, very energetic wavelengths, such as ultraviolet and X-rays. For UV light the intensity varies by a factor of 10 over the 11 year cycle, and for X-rays a factor of 100. Most of these wavelengths are absorbed in the atmosphere before they reach us. Ozone, for example, absorbs extreme ultraviolet, which, if it did penetrate, “our skin cancer rates would be horrible.” The UV and X-ray route is the second traditionally link between the sun and climate variability.

As well as the wavelength effects, the effect of particles such as electrons and protons needs to be considered. Thrown out by the sun, these change the chemistry of the polar upper atmosphere, one effect being to decrease the amount of ozone at 70 kilometres. This may possibly have a role in natural climate variability. As a result of the work of Prof Rodger's team on this issue, a representation of the effect, while still probably in need of refinement, is now being incorporated into some of the big international climate models. An exciting contribution given that “climate change is one of the biggest scientific problems facing us”.

Well, that’s my 1,000 words. As usual, there was a good deal more. Prof Rodger also touched on:

  • What causes the 11 year cycle (to do with the magnetic field of the sun as a gaseous body, so parts of it can spin at greater rates than other parts)
  • The probability of the earth’s magnetic poles switching soon
  • The possibility of there being more than one pair of magnetic poles
  • The possible effects of this, given, for instance, that many creatures use magnetic fields for navigation
  • Radioactive mutton-birds
  • Auroras and the solar minima and maxima
  • Mars and magnetism
  • The possibility of establishing extra-terrestrial human settlement
  • What to do with climate change nay-sayers

But one thing I cannot omit is Prof Rodger's anecdote about attending a conference in Pasadena very recently with 3,500 delegates on the topic of space research. As they were walking back from the opening function, there was a man standing on the side of the road, holding a placard which stated:
“The Earth is Flat. Space is Not Real”

*Prof Rodger used a different, more expressive, word here.

Posted: Wednesday August 8, 2018