Subject: Cascades2 report for Tues evening, Feb 24/25.

We were (mostly) in for winds tonight, but all of
our optical sites were blind.  The observers at
Toolik found 11 different words for snow, to vary
their hourly reports a bit...
We had a very fine substorm right at the optimal
textbook time (9:30-11UT, just in the 90 minutes
before magnetic midnight).  It was strong enough
to show light (but no structure) through the snow
at all 3 sites.  It is interesting to learn that
we are able to see the development of these substorms
using PFISR.  There are clear and repeatable observations
of flow patterns that call out the loading sequence
(southward expansion, westward flows) of a developing
substorm.  I'll ask Mike and Meghan to post an example
of this tomorrow, perhaps from one of the nights we
were out from winds but had good optics.  It is possible
that if learn to gauge this a little better and more
quantifiably, the PFISR could stand in for the optics.
Certainly not for the detailed structural picture
the optics give, but probably as an excellent tool
for "calling" the developing substorm.