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Polar Amplification At The South Pole

August 20, 2013
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By Paul Homewood

 

South Pole with ceremonial South Pole

Amundsen-Scott South Pole Station

   

I showed yesterday that summer temperatures in the Arctic had not increased in recent years, as polar amplification theory would suggest they should. But what about the South Pole?

Let’s take a look at the temperatures at the Amundsen-Scott station at the pole itself. Annual temperatures supplied by GISS, as below, show no upward trend, although there were a couple of spikes in 2002 and 2005.

 

image

http://data.giss.nasa.gov/cgi-bin/gistemp/show_station.cgi?id=700890090000&dt=1&ds=14

 

But what about summer? Remember that, according to polar amplification theory, the greenhouse effect should be amplified in summer because of the lack of water vapour. During winter months, of course, there is no greenhouse effect as the sun is not shining.

 

Using the monthly data from GISS, I have plotted the summer temperatures below.

 

image

http://data.giss.nasa.gov/tmp/gistemp/STATIONS/tmp_700890090000_14_0/station.txt

 

The trend line is essentially flat, with a slope of an insignificant 0.3C per century. Furthermore, the warmest summer was 1957/8, while the coldest was 1999/2000.

Five of the last seven years have been below the mean of minus 31.3C.

There is no evidence of any greenhouse effect, never mind polar amplification.

4 Comments
  1. Coldish permalink
    August 20, 2013 2:27 pm

    “During winter months, of course, there is no greenhouse effect as the sun is not shining.”
    Not quite clear to me what you mean here. Without any g-h effect would it not be much colder? There is still CO2 in the south polar atmosphere. Perhaps I’ve misunderstood something here.
    It might still be worth looking at the midwinter temperatures for South Pole and Vostok. As there is no daylight I’d expect there to be little diurnal variation and little variation over the whole sunless period in any given year. Without the high-frequency noise, interannual variation (if any) and any trend attributable to CO2 increase should be more obvious than in summer. That’s assuming that the tropopause is above ground level.

    • August 20, 2013 4:22 pm

      According to Wiki

      Solar radiation at the frequencies of visible light largely passes through the atmosphere to warm the planetary surface, which then emits this energy at the lower frequencies of infrared thermal radiation. Infrared radiation is absorbed by greenhouse gases, which in turn re-radiate much of the energy to the surface and lower atmosphere.

      http://en.wikipedia.org/wiki/Greenhouse_effect

      At night, there is a still a small amount of thermal radiation as the surface cools down, but by winter this must be insignificant.

      Interestingly, if you look at 2012 seasonal temps at Scott Base:-

      Summer – minus 32.3C
      Autumn – minus 56.4C
      Winter – minus 59.4C
      Spring – minus 49.3C

      In other words, most of the cooling down takes place in Autumn.

  2. Brian H permalink
    August 21, 2013 3:36 pm

    ‘What if there was no CO2?’ is an interesting theoretical question, but pretty hard to tie to observations.

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