where to see the
Aurora Borealis
In general, you are more likely to see an aurora if you are at a high
latitude, i.e. closer to the north (or south) pole. However, there is a
catch to this. The earth's magnetic poles are not exactly in line with the
geographic poles, so the latitude of interest would really be the magnetic
latitude. Note that it is not necessary for the equatorward boundary of
the aurora to reach all the way down to your magnetic latitude for you to
see it. The aurora is easily visible even when its boundary is 4 or 5
degrees poleward of your location. So, how do you know what your magnetic
latitude is? We have several methods to help you:
North America |
Europe and Asia |
Southern Hemisphere |
City |
Magnetic
Latitude* |
City |
Magnetic
Latitude* |
City |
Magnetic
Latitude* |
Atlanta |
44.5 |
Athens |
31.3 |
Adelaide |
45.9 |
Boston |
51.7 |
Berlin |
48.3 |
Buenos Aires,
Argentina |
23.3 |
Chicago |
52.2 |
Copenhagen |
51.9 |
Capetown |
41.5 |
Dallas |
42.7 |
Edinburgh |
53.0 |
Christchurch |
49.9 |
Denver |
48.3 |
London |
47.5 |
Comodoro
Rivadavia, Argentina |
32.1 |
Great Falls,
MT |
54.9 |
Madrid |
33.3 |
Concepcion,
Chile |
23.2 |
Havana |
34.1 |
Moscow |
51.8 |
Dunedin |
53.0 |
Los Angeles |
39.8 |
Paris |
44.2 |
Durban |
38.8 |
Mexico City |
29.1 |
Perm |
53.8 |
East London |
41.1 |
Minneapolis |
55.1 |
Prague |
45.5 |
Hobart |
53.6 |
New York |
50.6 |
Rome |
35.5 |
Melbourne |
48.4 |
Quebec City |
56.2 |
St.
Petersburg |
56.1 |
Perth |
43.9 |
San Francisco |
42.5 |
Warsaw |
46.7 |
Punta Arenas,
Chile |
38.6 |
Seattle |
52.7 |
Beijing |
34.1 |
Sydney |
43.5 |
St. Louis |
49.2 |
Irkutsk |
47.0 |
|
Toronto |
53.9 |
Seoul |
31.0 |
Washington,
DC |
49.1 |
Tokyo |
29.0 |
Winnipeg |
59.5 |
Vladivostok |
36.5 |
When geomagnetic activity
is low, the aurora typically is located, in the hours around midnight, at
about 67 degrees magnetic latitude*. As activity increases, the region of
aurora expands toward the equator. When geomagnetic activity is very high,
the aurora may be seen at mid and low latitude locations around the earth
that would otherwise rarely experience the polar lights.
Kp maps of midnight
equator-ward boundaries
There are maps for four quadrants of the
globe:
North America
Eurasia
South America and Eastern Pacific
Africa-Indian Ocean-Australasia
The average equator-ward boundary of the
midnight aurora is shown for levels of magnetic activity ranging from
relatively low, Kp=3, to very high, Kp=9. Clicking on the map at that
location will give the approximate magnetic latitude for that location.
(Keep in mind that aurora can still be viewed when it is positioned 4-5
degrees in latitude away from the viewer although it will appear about 20º
above the horizon.) These maps were created using satellite observations
to determine the average equator-ward boundary of the aurora as a function
of the Kp index**. Using those data, the typical maximum extent of the
aurora toward the equator for the hours around midnight for four levels of
geomagnetic activity is displayed.
* Corrected magnetic latitude
**The Handbook of Geophysics and the Space Environment, Air Force
Geophysics Laboratory, 1985
putting
it all together
Once you know your
magnetic latitude, and how high the Kp index needs to be for you to see
the aurora at your magnetic latitude, it comes down to choosing a viewing
time of high magnetic activity by frequently checking the Kp index and SEC
forecast. (The
table below will help you relate the POES Auroral Activity Level to the Kp
index.) Of course, for you to see the aurora it will also have to be a
clear night without interference from city lights or moonlight.
Comparison of Auroral Boundaries from Kp and Auroral
Activity Level at Local Midnight |
Magnetic Latitude |
Kp |
|
Magnetic Latitude |
NOAA
POES Auroral Activity Level |
66.5 |
0 |
|
67.5 |
1 |
64.5 |
1 |
66.5 |
2 |
62.4 |
2 |
65.6 |
3 |
60.4 |
3 |
63.9 |
4 |
58.3 |
4 |
62.5 |
5 |
56.3 |
5 |
60.7 |
6 |
54.2 |
6 |
58.6 |
7 |
52.2 |
7 |
56.7 |
8 |
50.1 |
8 |
54.6 |
9 |
48.1 |
9 |
51.0 |
10 |
|
48.5 |
10+ |
45.0 |
10++ |
|