Please contact Ruth Skoug (rskoug@lanl.gov, 505-667-6594) if you have 
any questions or comments about these data.

This directory contains SWEPAM ion data for 4 storms:

July 10-18, 2000
Sept 24-27, 2001
Nov 5-7, 2001
Oct 28 - Nov 4, 2003

The files are all ascii text files, and the parameters included are
described at the top of each file.

This directory also includes a copy of our JGR paper about the Oct-Nov,
2003 events, which should be read carefully before using the data from
that interval.  

Below are specific notes about each event.

NOTES ON THE TIME RESOLUTION OF THE DATA.

Each SWEPAM measurement takes 64 seconds.  Under normal conditions, the
SWEPAM instrument is designed to track the energy of the solar wind beam,
and collects data with 5% energy resolution at energies around this peak,
selected from a range of ~250 eV/q - 35 keV/q.

Once every 30 measurements (approximately 32 minutes), SWEPAM makes at
measurement with reduced energy resolution over the entire energy range
of the instrument, from ~250 eV/q to 17.5 keV/q.

At times when the solar energetic charged particle background is high, 
as was true for all of the storms listed here, the tracking algorithm
becomes confused, and the instrument instead makes measurements at the
lowest available energies.  When the solar wind speed is high, this means
that the solar wind beam is not adequately covered by the measurement.

At these times, then, only data with ~32 minute time resolution are
available from SWEPAM, as is reflected in the data files provided here.

Note that these are still 64-second snapshots collected once every 
32 minutes, NOT 32 minute averages.

Also note that, because of the reduced energy resolution, these data are
not of Level 2 quality, and thus have not been included in the Level 2
data set.  Care should thus be taken in using these data. 

SPECIAL NOTE FOR THE JULY, 2000 EVENT:

There is a single-point increase in density following the shock
at 14:16 UT on day 197.  Based on the particle distributions, I
believe this density increase is real, and is observed for only
a short time because of 1) the low SWEPAM time resolution, and
2) the disturbed nature of the plasma following the shock.

SPECIAL NOTES FOR THE OCT-NOV, 2003 EVENTS:

Please note that these events were at the very edge of what
SWEPAM can measure, so the uncertainties in the data are larger
than is typical.  In particular, the data for the very highest-speed
point are not really adequate, so I would strongly suggest that you
not base any conclusions on the exact quantitative value of the
speed at this time.  Please read the appropriate section of our paper
for warnings about the SWEPAM density values for portions of this
event.  I would also strongly suggest that you contact
Toshio Terasawa (terasawa@eps.s.u-tokyo.ac.jp) to get Geotail
PWI density values for times when they are available (06 UT on Oct 29
to 04 UT on Oct 30).

Also note that the file includes magnetic field data from the ACE 
magnetometer, but at the same low time resolution as the plasma data.  
If you want to do scientific analysis of the magnetic field data, you
should get the high time resolution data from the ACE Science Center.