Aurora Borealis, November 2023

Almost 20 years ago to the day (+5), there was finally a polar sighting again in southern Bavaria. And this was really great. I would even classify this aurora as clearly visual up to bright, but the color spectacle only lasted 5-10 minutes. Abouve all the pink beamer were noticable very intense. The strongest phase with KP Index 7* took place around 6:10 p.m. CET, followed by a visually weaker phase at 8:30 p.m.

Just in time ;-)

These recordings are due to pure chance. I actually wanted to check the weather conditions and the incoming rain area without a camera. Okay maybe I take the camera and tripod for a quick time-lapse with me ? After all, the KP Index* had reached already 6. Already in the village I noticed the bright red sky in the northeast between the street lamps. From then on I ran up the hill like 2003, not for nothing! Five minutes later ...

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 and from ~100-200 km red to orange colors. Nitrogen atoms up to ~300 km height shows more seldom purple or blue colors.