The ionosonde of the WestPac Experiment at Cebu, Philippines is
within 1 deg of the magnetic dip equator. It is used to determine
the vertical plasma drift between 1730LT and 1930LT. The
ionograms are hand scaled and reduced to true heights using
the POLAN scaling program. The bottomside true-height profiles
are then used to determine the vertical plasma drift. Before
1730LT the plasma drift determined is an apparent drift created
by the decay of the bottomside ionosphere due to chemistry.
After 1930LT the bottomside of the descending ionosphere is again
affected by chemistry, thus, the calculated drift is not real.
We have nearly 2 months of data. It is being reduced presently.
Three nights below are analyzed. They are representative of
three conditions (1) spread F night, (2) strong spread F night,
and (3) no spread F night.
The vertical drift calculated from the true-height profiles are used
to drive a model ionosphere. The resulting ionosphere is used
to examine Rayleigh-Taylor growth rates and non-linear instability
development.
The CEBU ionograms were provided by Dr. Nozaki, a co-investigator
in the WestPac campaign.
