|
|
|
|
Welcome
to Astronomy North • Your Official Source for Skywatching News
and Information in Yellowknife, Canada
|
|
|
| |
|
About This Forecast
|
|
ACTIVITY
LEVEL
|
What
is the Activity Level?
The estimated overall frequency and intensity
of auroral activity in the skies above Yellowknife
from dusk until dawn. |
|
How
Does Astronomy North Predict the Activity Level
for Yellowknife?
Our
formula for predicting auroras above Yellowknife
is based on an incremental 10-point ranking system
that assesses the potential of four principle
variables known to influence the intensity and
frequency of auroras as seen from Earth.
Activity
Level Variables
INTENSITY = Solar Wind Speed (min=0.5 max=3)
DENSITY = Solar Wind Density (min=0.5 max=3)
FREQUENCY = Magnetic Field Flux (min=0.0 max=3)
VISIBILITY = Atmospheric Conditions (min=0.0,
max=1)
Activity
Level Formula
INTENSITY + DENSITY + FREQUENCY + VISIBILITY =
ACTIVITY LEVEL 1-10
Activity
Level Ratings
CALM = 1.0, 1.5,
2.0, 2.5
MODERATE = 3.0, 3.5,
4.0, 4.5
ACTIVE = 5.0, 5.5,
6.0, 6.5, 7.0, 7.5, 8.0
EXTREME = 8.5, 9.0,
9.5, 10.0
Monitoring
Solar
Wind
Explosive clouds of charged particles ejected
from the Sun are commonly referred to as the Solar
Wind. The speed and density of this Solar Wind
directly influence the intensity and frequency
of auroras on Earth. Solar
Wind Speed is monitored using real-time information
transmitted to Earth from the ACE
spacecraft and reported by the NOAA
Space Environment Center. |
|
| |
|
|
|
PEAK
TIMES
& INTENSITY
|
Early
Aurora
Indicates the activity level forecast for
Yellowknife, Northwest Territories before 11 p.m.
Mountain Standard Time. |
|
Late
Aurora
Indicates the activity level forecast for
Yellowknife, Northwest Territories after 11 p.m.
Mountain Standard Time.
Peak
Intensity
Indicates the estimated maximum intensity
of auroral activity from dusk until dawn on a
scale of 1-10.
Sky
Conditions
Indicates atmospheric clarity on a scale of
1-10, including weather conditions and upper atmospheric
distortion above Yellowknife,
Northwest Territories.
|
|
| |
|
|
|
COLOUR
|
Colour
Anticipated spectrum of auroral colours above
Yellowknife, Northwest Territories based on solar
wind and atmospheric variables. |
|
Colour
Variables
Auroral colours are influenced by the intensity
and composition of the solar wind, the density
of gases in Earth's atmosphere and darkness/moonlight
levels. The most common colour above Yellowknife
is green, caused when an electron-rich solar wind
collides with molecular oxygen in Earth's atmosphere.
|
|
| |
|
|
|
MORE
GREAT SPACE WEATHER
SITES
Space
Weather Canada
• LINK
Spaceweather.com
• LINK
Alaska
Geophysical Institute •
LINK
NOAA Space
Environment Centre •
LINK
|
 |
STARGAZING
Mapping the stars above Yellowknife, Northwest
Territories |
|
 |
ASTROQUEST
Astronomical
answers to frequently asked questions |
|
|
|
|
|
|
 |
ATMOSPHERE
There's
more to the sky than meets the eye |
|
|
|
|
|
 |
