Red Sprites & Blue Jets

Minho

Cumulonimbus
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6 Set 2005
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Melgaço
Neste tópico também já se tinha abordado esse fenómenos espectaculares
 

Minho

Cumulonimbus
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6 Set 2005
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Obrigado pelas informações disponibilizadas.

Contudo no video nocturno, em tons de verde, filmado no Iraque por tropas americanas, aquelas luzes serão sprites ou jets? Elas estão fixas e não parece estar a trovejar.

Alguma sugestão? Vá lá, não sejam mauzinhos :lmao:

O que está nesse video são tudo menos sprites, jets, elfos ou coisa que valha. Um sprite tem um tempo de vida inferior a 1 segundo por isso jamais seria possível ficar a filma-los uma e outra vez de câmara na mão. Mais, os sprites ou jets dão-se sempre no topo das nuvens não no meio das nuvens como aparenta o vídeo.
 

Orion

Furacão
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5 Jul 2011
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Açores
Deixo aqui um guia e um vídeo recente. Assumo eu que é mais facilmente visível em Portugal Continental porque nos Açores a nebulosidade semi-permanente torna a visualização impossível:




Video (ver site para conhecer o método utilizado):

[ame="http://vimeo.com/99434364?email_id=Y2xpcF90cmFuc2NvZGVkfDI5Mzk1ZDRhMGQ3MmE1Y2U2Yzc0NTViOWVhMmRjYWU3NTAyfDgwNzA3Nzh8MTQwNDAxMTQ2MHw3NzAx&utm_campaign=7701&utm_medium=clip-transcode_complete-finished-20120100&utm_source=email"]Mesosphere Waves & Sprints - 27 June 2014 on Vimeo[/ame]


Breve descrição do fenómeno:

The sprite show continues. "Every day this week, I have been able to photograph red sprites shooting up from the tops of thunderstorms 400 miles away in Colorado, Nebraska and Kansas," reports Jan Curtis of Santa Fe, NM. On June 27th he saw something more: "At around 10:30PM MDT, gravity wave clouds developed and intensified through midnight."

(...)

"While I could not detect them with my unaided eyes, time lapse video revealed that the waves were moving very slowly to the northeast," says Curtis.

The waves are, literally, the ripple effect of a powerful thunderstorm on the mesosphere some 80 km above Earth's surface. From space, these waves look like a giant atmospheric bull's eye. The green hue comes from airglow, an aurora look-alike that can be seen on very dark nights from any place on Earth.

Although airglow resembles the aurora borealis, its underlying physics is different. Airglow is caused by an assortment of chemical reactions in the upper atmosphere driven mainly by solar ultraviolet radiation. Auroras, on the other hand, are fueled by gusts of solar wind. While auroras are confined mainly to polar regions, airglow makes a luminous bubble that surrounds the entire planet.

The undulations in the airglow Curtis photographed are caused by temperature and density perturbations rippling away from the central axis of the distant thunderstorm. Speaking simplistically, those perturbations alter chemical reaction rates in the upper atmosphere, leading to more-bright or less-bright bands depending on whether the rates are boosted or diminished, respectively.

Inhabiting the upper reaches of Earth's atmosphere alongside meteors, noctilucent clouds and some auroras, sprites and mesospheric gravity waves are true space weather phenomena. Now is a good time to see them.

http://www.spaceweather.com/
 
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