From: [email-masked] (Cassandra Fesen)
Date: Thu, 7 Mar 96 12:41:45 EST

Hi Ben --
a question (I think I asked this before, maybe more than once, but it's one
of those things that always can cause confusion:)

I am using an older version of  the model post-processor, tigcmloc, and
used ionvel=2 to get out drifts and also ve and vu.

I get back things labeled:

TIEGCM magnetic zonal ion drift (exb + unvn)
TIEGCM magnetic meridional ion drift (exb + unvn)
TIEGCM magnetic vertical ion drift (exb + unvn)
VE (m/s perpendicular to mag field, +east)
VU (m/s perpendicular to mag field, +up)

the question is re the magnetic (zonal, meridional, vertical) drifts:
are these the drifts in the geographic coordinates?  So the results
represent the drifts at the model gridpoints which are in the
geographic east, geographic north, and geographic (radial) up direction?
For the horizontal components, these would have had a projection of 
ExB drift onto the horizontal plane taken into account, and added to 
this would be the neutral wind contributions in the appropriate directions.  

Part of what's confusing me is the label "magnetic" on the first
3 quantities listed ("TIEGCM magnetic zonal..., TIEGCM magnetic
meridional ..., etc.)

The VE and VU:  like it says, these are essentially the ExB drifts
part, referenced to the geomagnetic field line, so VU is the
drift perpendicular to the field line in the upward direction and
VE in the eastward direction.

Anyhow, thanks for going through this again with me,

Cassandra