Photographed on 9th of May 2018 from Fuerstenfeldbruck / Germany
On 9th of May bright Red Sprites appeared over the 350 km distanced region of Milano (North Italy)
Sony a 6300, 4k, Sigma f1.4, 35mm, Iso 3200, exp 1/5 sec
Weather Situation on 09th of May 2018, 22:25
In courtesy of Sat24
About Red Sprites
A red sprites appearance lasts from ~20 to ~100 milliseconds, but can be very bright and visible to the naked eye in dark areas.However, the brightness remains several times below a lightning discharge. On average, red sprites appear at an altitude of about 40 - 90 km from the stratosphere (<50km) through the mesosphere to the thermosphere (>80km). Sightings up to an altitude of 100 km in the thermosphere are also possible. The height dimension of a single sprite varies from ~10 km to ~60 km, the width can possibly reach 5 - 30 km. However, some 'sprite walls' or 'multiple sprites' can exceed 100km horizontally.
But how does the rare luminous phenomena come to this name, when they were discovered and what is the reason of origin?
Until 1989, the existence of Red Sprites was generally denied because only jet pilots announced sporadic sightings. Here they reaped rather grumpy and sarcastic reactions :-(. Thus, many sightings have been omitted. 1989 the first Red Sprite photos did succeed, but due to the not yet advanced camera technology the results were scientifically useless. 1991 the astronauts of the former Space shuttle mission succeeded photographically to capture this phenomenon specifically the first time from space. These photos served as the first meaningful evidence. Afterwards high-tech peppered research aircrafts were inserted by very costly experiments from the NASA and NOAA, which should explain and analyze these phenomena further. After this efforts yielded no results for months, and the researchers literally get messed around with this situation, the called these discharges almost mischievously 'Sprites'. But after a while and patient effords impressive high speed filmings succeeded.
By the way, there is still no definitive plausible explanation for the origin of Red Sprites, but there are countless theories. One theory explains that large energetic thunderstorm cells charge prior to lightning discharge, forming a (-e) leveling layer over the top of the cell. The initiator is always a violent positive! cloud-to-ground lightning which causes charge shifts (+) in the upper areas of the thunderstorm cell. Now the overlying (-e) layer is preserved longer and faces the (+) charged upper ionosphere (>90km). An quasi oversized electrostatic field is created for a short time according to the principle of a plate capacitor, which produces the surge, the so-called red sprite. This electromagnetic impulse ionizes nitrogen atoms from the stratosphere (<50km) to the upper thermosphere (90km) and causes them to glow through fluorescence (cold plasma, fluorescent tube principle or polar light).
In addition, another theory explains that the luminous phenomenon could be caused or supported by the cosmic gamma radiation that always occurs in the ionosphere. The cosmic gamma rays probably produce an (-e) chain reaction by collision. Thus a high-energy ion-electron cloud (-e) which reaches into the upper thermosphere (90km) arises, whereby the typical and unique sprite forms appears. There is also a scientific report in the Washington post which explain some theories.
More Red Sprites info
All Red Sprites & Auroras