Current auroral
activity
This plot shows the
current extent and position of the auroral oval in the northern
hemisphere, extrapolated from measurements taken during the most recent
polar pass of the NOAA POES satellite.
The red arrow
in the plot, that looks like a clock hand, points toward the noon
meridian.
The statistical pattern
depicting the auroral oval is appropriate to the auroral activity level
determined from the power flux observed during the most recent polar
satellite pass. The power fluxes in the statistical pattern are color
coded on a scale from 0 to 10 ergs .cm-2.sec-1
according to the color bar on the right. The pattern has been oriented
with respect to the underlying geographic map using the current universal
time, updated every ten minutes.
This presentation provides
an estimate of the location, extent, and intensity of aurora on a global
basis. For example, the presentation gives a guide to the possibility that
the aurora is located near a given location in the northern hemisphere
under the conditions that existed at the time of the most recent polar
satellite pass.
Normalization factor
(n)
A normalization factor of less than 2.0 indicates a reasonable level of
confidence in the estimate of power. The more the value of n exceeds 2.0,
the less confidence should be placed in the estimate of hemispheric power
and the activity level.
The process to estimate
the hemispheric power, and the level of auroral activity, involves using
this normalization factor which takes into account how effective the
satellite was in sampling the aurora during its transit over the polar
region. A large (> 2.0) normalization factor indicates that the transit
through the aurora was not very effective and the resulting estimate of
auroral activity has a lower confidence.
This plot shows the
current extent and position of the auroral oval in the southern
hemisphere, extrapolated from measurements taken during the most recent
polar pass of the NOAA POES satellite.
The red arrow
in the plot, that looks like a clock hand, points toward the noon
meridian.
The statistical pattern
depicting the auroral oval is appropriate to the auroral activity level
determined from the power flux observed during the most recent polar
satellite pass. The power fluxes in the statistical pattern are color
coded on a scale from 0 to 10 ergs .cm-2.sec-1
according to the color bar on the right. The pattern has been oriented
with respect to the underlying geographic map using the current universal
time, updated every ten minutes.
This presentation provides
an estimate of the location, extent, and intensity of aurora on a global
basis. For example, the presentation gives a guide to the possibility that
the aurora is located near a given location in the southern hemisphere
under the conditions that existed at the time of the most recent polar
satellite pass.
Normalization factor
(n)
A normalization factor of less than 2.0 indicates a reasonable level of
confidence in the estimate of power. The more the value of n exceeds 2.0,
the less confidence should be placed in the estimate of hemispheric power
and the activity level.
The process to estimate
the hemispheric power, and the level of auroral activity, involves using
this normalization factor which takes into account how effective the
satellite was in sampling the aurora during its transit over the polar
region. A large (> 2.0) normalization factor indicates that the transit
through the aurora was not very effective and the resulting estimate of
auroral activity has a lower confidence.
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