Why are the results different for the same run on the web versus the PC?

There are several possiblities for the differences you are seeing.

  1. the version of HYSPLIT may be different….we test new updates to HYSPLIT on the web site before releasing them to the PC version,
  2. the values we set in the SETUP.CFG and CONTROL files may be different than what you have set in yours,
  3. finally, due to the random number generator, the dispersion will be very slightly different when running the same case on different computing platforms.

Glenn Rolph