At first the end of the main attraction.
23:17
CET: Nice to see the 140°
red arc, may it is a
deformed SAR bow. (Composite
of 3 images)
KP
index ca. 8+ / 9-
Intensive colours
/
Weaker colours
Still missing the hour before
...
... but on the 20th of January
fine auroras appeared again
18:30; CET: The view from
Lugberg/Germerswang looking north
shows a pink polarlight
19:40h: And now a aurora borealis actually
appeared more red with strong beamer
Change of place
23:30, Again a deep red aurora appeared
:-)
The final red,
KP index ca. 7+
Look at the aurora in Mai
2024
Basics about
sightings of Aurora Borealis also known as Northern- or polar lights,
in middle latitudes
KP index*:
Roughly speaking, auroras can already be observed visually from
KP 5-6 (G1/2 storm)
in northern Germany. At
KP 7/8 (G3/4 storm)
or above
also in southern Germany (Alps to southern Europe). Among
other things, the density and speed of the flares or CME's
(earth directed solar mass ejection forms) or corona holes are relevant
parameters for the strength of the solar storms and visual
sightings. But the Bz value
which definite the north- south alignment of the
earth magnetic field ( May 2024, Bz -50nT ) is the most important factor.
If this Bz value
is to weak, the protons can't invade in the earth magnetic
field. By the way, the glowing phenomenon is triggered by
'animated' oxygen and nitrogen atoms. Oxygen up to ~100 km
shows
greenish
colors and from
~100-200 km
red to orange.
Nitrogen atoms up to ~300 km
shows more seldom purple
or blue
colors.
NOAA Space
Weather
Prediction Center
Aurora Borealis & Atmospheric phenomena
