For solar wind dials without any explanatory text, see
It also has a few dials that are not shown here. A web page with more
is also available.
Current Space Weather Status
This "stoplight" shows the most severe of the following three
gauges of space weather:
This index is based on the most recent USAF/NOAA estimated planetary
geomagnetic activity (KP) 3-hour index. Our index is
determined as follows:
|Condition||Estimated (3-Hour) KP|
|| KP < 4|
|| 4 <= KP < 7|
|| KP >= 7|
This index is keyed to the estimated instantaneous asymptotic
voltage across the polar cap, the
single most important measure of electrical power delivered to the
atmosphere from the solar wind. We now use data from the
ACE Real-Time Solar Wind
package since this spacecraft is tracked more often than WIND.
(The old estimate was based on observations from NASA's
The index is determined as follows:
|Condition||Polar Cap Potential (PCP) Range|
|| 0 kV <= PCP < 110 kV|
|| 110 kV <= PCP < 200 kV|
|| PCP >= 200 kV*|
* The PCP status is changed to red only if the current
10-minute average exceeds 200 kV AND the previous 10-minute average
exceeds 150 kV. This is designed to reduce shifts in status due to
short-term spikes in the value of the potential.
This index is based on the forecasted geomagnetic event probabilities
over the next two days (section VI of the
|Condition||Next Day Probabilites (P1)
||Second Day Probabilities (P2)|
||P1 <= 35%||P2 <= 35%|
||35% < P1 < 50%||P2 > 35%|
||P1 >= 50%||Not Applicable|
Latest Observations from the
Last Measurement (at Sun-Earth L1 Point): April 3, 2005 09:27 UT
Sun-Earth L1 Point is approximately 45 minutes upwind of the Earth.
Interplanetary Magnetic Field
You can now receive e-mail notification whenever the stoplight sets to red!
(Actually, you can be notified whenever any of these conditions change.)
Just go to the
Rice University Lists and subscribe to the SPACALRT Mailing List.
To unsubscribe follow the instructions on the SPACALRT Mailing List
page, or send an e-mail to
Stoplight state changes are once again logged. There are three logs,
one for each condition index
The earliest logged transition occurred on September 25, 2003.
More about the solar wind's recent behavior can be found on the
Current Solar Wind Conditions page.
Also, here's an index to
Space Weather Resources.
Other items of interest include
NOAA/SEC Current Conditions, the composite current
Auroral Images page,
Windows on the Universe: Space Weather, and
Public Outreach Index,
Department of Physics and Astronomy, Rice University.
Patricia H. Reiff
Department of Physics & Astronomy
Static information was last revised on 10/31/2003.