In article , "starman"
wrote:

How predictable is the orientation of the IMF and Bz?

Predicting the direction of Bz from remote measurements is an unsolved
problem. However NASA's ACE spacecraft, at the L1 point between the Earth
and the Sun, can measure IMF at its location. The IMF in the vicinity of
the Earth lags this by about an hour (the time it takes for the solar wind
to travel from L1 to Earth). NOAA taps into the ACE data stream and posts
it on line.

Raw ACE magnetometer data may be inspected at:

http://solar.sec.noaa.gov/ace/MAG_6h.html

NOAA also cooks this and other ACE data into a prediction for Kp at:

http://sec.noaa.gov/rpc/costello/pkp_15m_24h.html

Last year I went to a workshop at NOAA in Boulder to discuss future
spacecraft. ACE is a one-shot NASA science mission. NOAA wants to have its
own interplanetary space weather monitoring program so that when the ACE
mission ends NOAA can continue to make these predictions.

One wild idea was to use a solar sail to hold a spacecraft in a orbit
closer to the Sun than L1, so the lead time would be greater.

--
| John Doty "You can't confuse me, that's my job."
| Home:
| Work: