Antarctica is the continent renowned for being covered with ice and home to a handful of humans assigned to research posts. The other notable inhabitants of Antarctica are the variety of penguin species which call the frigid continent home. With the mascot of the world's fastest growing operating system, Linux, a slightly overweight penguin by the name of TUX, Computerworld Antarctica decided to take a peek at where and how Linux is being used on the southern icecap.
One of the largest research organisations concerning polar regions is The Antarctic CRC, or Cooperative Research Centre. The centre, which is located at the University of Tasmania (www.antcrc.utas.edu.au), incorporates scientific research of both Antarctica and the Southern Ocean.
One such research project being conducted at The Antarctic CRC is the 2 and 3 dimensional modelling of the ocean beneath the Amery Ice Shelf which is approximately the same area as Lake Michigan. "We are using a 2-D model to simulate tides and a 3-D model to simulate the currents caused by the melting and re-freezing of ice under the shelf," said John Hunter, a CRC researcher in applied marine science and formerly a Principal Research Scientist in the Division of Marine Research at the CSIRO. It is hoped that this work will lead to more evidence in determining whether global warming is reducing the overall size of the ice shelf.
"We both use Linux as our standard operating system, running on Pentium machines," added Hunter. "For long runs the 3-D model is migrated to our Cray supercomputer. The 3-D model is written in Fortran-77 and compiled on my Pentium machine using g77 [Fortran-77 compiler]."
As for why Hunter chooses to use Linux for his work, the reasons are many. "I can't really imagine how I would do serious modelling work on anything other than a Unix system of some sort. Modelling is not generally just a case of running a model - it involves considerable data manipulation both at the input and output end," explained Hunter. "I know there are several "MathCad-type" packages around on Windows, but they do tie one into quite a limited range of manipulation options." He also cited the flexibility of a command-line interface as crucial to the type of work that he does.
One example given by Hunter as to why he uses Linux involves the amount of data that he gathers from a variety of sources. "The data that we use includes the bathymetry of the sea bed, thickness of the ice shelf, tidal elevations, temperature and salinity of sea water, all of which comes from a wide variety of sources and formats," said Hunter. "I believe that it is only under a command-line operating system such as Unix that one can guarantee to be able to reformat any data file."
The financial incentives of using Linux also play a part. "On a power per dollar basis, Pentium PCs win hands down. I choose to use a PC for most of my work, in which case Linux becomes the natural choice of operating system," remarked Hunter. "I also often work very much on my own when at sea for relatively long periods (10 weeks off the Amery last year) and I have to be able to maintain the operating system myself. Lastly, Linux is virtually free, and we are not over-endowed with funding for our computational needs."
In future issues, Computerworld Antarctica will be looking at other case studies where Linux is being used.