January 3, 2011... Heading back after two mesmerizing weeks.

I was trying to get the most of the last few hours at the South Pole, especially since we did not have much free time to see the other science done at this end of the world. There is a lot of astronomy done around here; there is a 10 meter radio telescope, the South Pole Telescope to study the cosmic microwave background, the world's largest neutrino observatory, Icecube etc. The extreme engineering used in many of these instruments are simply mind boggling. In fact,

the new South Pole station is itself an engineering marvel. More details can be seen at

http://www.nsf.gov/news/special_reports/livingsouthpole/intro.jsp.

I got an opportunity to visit the Icecube which is a net of 86 -- 2.5 km deep cores drilled in the ice and having 60/well photomultiplier tubes a 1 km below the surface in an area of 1 cubic km (hence the name) to detect neutrinos.. phew.. that's a mouthful, isn't it? They had a very graphical display of the neutrinos being detected almost in real time (half an hour delay because of filtering etc. processes) at the main control building. I also could peep into one of the open wells. The drilling in the ice is done by gushing highly pressurized boiling hot water into a small cylindrical area. It was just thrilling to digest the fact that I was standing on the world's largest detector in ice.

The Icecube visit was right after midnight (remember it is a 24 hour day down there?!).. Early morning, I got up and got ready to visit the Atmospheric Research Observatory (ARO). Surprisingly, it was overcast and there was no difference to be seen between the sky and the snow. The horizon was just not visible. I hiked to the ARO building (just 5-10 minutes from the station). Looked at the different instruments and their research on the Antarctic air. It was nice to finally learn why does the ozone hole exist over this continent especially since there are no human colonies to produce the Chloroflurocarbon (CFC) from the refrigerants. As we know, CFC acts as a catalyst to disintegrate ozone. Well, it is a year round process that creates this ozone hole over Antarctica. CFC from around the world is channeled to the South polar cap with the complicated air flows over the winter. Over the summer, there is enough heat due to the sun to initiate the disintegration of ozone gas with the trapped CFC playing the major role. I learnt that there has to be someone year round to take daily measurements from different instruments, calibrate them, take field measurements of carbon dioxide from the clean air sector. This brings me to the final exciting thing. There is a conical area emerging from the South Pole which is called as the "Clean Air Sector", where for hundreds of miles, no pollution is allowed: no vehicle, plane allowed, no combustion thus no power plants are allowed, not even a soul person is allowed to venture out in that area. Furthermore, it is towards the north side which is plateau side and is towards a higher altitude that South Pole, thus, the air/wind always blows from that region down to the station. In short, the air is not contaminated by anything in that designated area that makes it the area with cleanest air on the Earth. So, I got to fill up my own bottle of the cleanest air sample and seal it to receive probably one of the best souvenirs from the South Pole.