Science

NORUSCA II camera sheds new light on auroras

NORUSCA II camera sheds new li...
An aurora appearing in the night sky at the Kjell Henriksen Observatory in Svalbard, Norway, taken November 2010 (Photot: Njaal Gulbarndsen)
An aurora appearing in the night sky at the Kjell Henriksen Observatory in Svalbard, Norway, taken November 2010 (Photot: Njaal Gulbarndsen)
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The NORUSCA II camera
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The NORUSCA II camera
The aurora as seen as a color composite image from the NORUSCA II camera – three bands were combined to make the image with each band assigned a different color -- red, green, and blue – to enhance the features of the aurora for analysis (Photo: Optics Express)
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The aurora as seen as a color composite image from the NORUSCA II camera – three bands were combined to make the image with each band assigned a different color -- red, green, and blue – to enhance the features of the aurora for analysis (Photo: Optics Express)
The red arrow points to the unidentified low-intensity wave pattern, which the researchers suspect is an auroral-generated wave interaction with airglow, while, for contrast, the blue arrow points to the faint emission of the Milky Way (Photo: Optics Express)
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The red arrow points to the unidentified low-intensity wave pattern, which the researchers suspect is an auroral-generated wave interaction with airglow, while, for contrast, the blue arrow points to the faint emission of the Milky Way (Photo: Optics Express)
An aurora appearing in the night sky at the Kjell Henriksen Observatory in Svalbard, Norway, taken November 2010 (Photot: Njaal Gulbarndsen)
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An aurora appearing in the night sky at the Kjell Henriksen Observatory in Svalbard, Norway, taken November 2010 (Photot: Njaal Gulbarndsen)
Students perform measurements of the aurora in front of the Kjell Henriksen Observatory in Svalbard, Norway, November 2010 (Photo: Njaal Gulbarndsen
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Students perform measurements of the aurora in front of the Kjell Henriksen Observatory in Svalbard, Norway, November 2010 (Photo: Njaal Gulbarndsen

Even those of us not lucky enough to have witnessed them in person will likely have marveled at photos of the stunning auroras caused by high energy particles from the Sun colliding with atoms in the Earth’s atmosphere. A team of space-weather researchers has now developed a new camera called NORUSCA II that has produced the first-ever hyperspectral images of the aurora borealis (or northern lights) and may have uncovered a previously unknown atmospheric phenomenon.

Until now, even the cameras used to capture images of the auroras for scientific analysis have collected all the light together in one image. This meant that researchers looking to analyze specific bands or a small portion of the spectrum would need to use a series of filters to capture a series of images.

The NORUSCA II takes a similar approach, but using advanced optics it can achieve the same result with no moving parts ... and much, much faster. The camera can switch between all of its 41 separate optical bands in a matter of microseconds, allowing specific bands of the auroras to be combined into one image.

“A standard filter wheel camera that typically uses six interference filters will not be able to spin the wheel fast enough compared to the NORUSCA II camera,” said Fred Sigernes of the University Centre in Svalbard (UNIS), Norway. “This makes the new hyperspectral capability particularly useful for spectroscopy, because it can detect specific atmospheric constituents by their unique fingerprint, or wavelengths, in the light they emit.”

The researchers say the NORUSCA II’s multispectral imaging capabilities will shed new light on the way the Earth responds to solar storms by allowing scientists to better classify auroras from background sky emissions and study the way they cluster in the atmosphere.

The camera’s inaugural research campaign may have already revealed a previously unknown atmospheric phenomenon. A Coronal Mass Ejection (CME) resulting from a major solar flare on January 24, 2012, eventually slammed into the Earth’s magnetic field, providing a perfect chance for the team to fully test the camera. This was done at the Kjell Henriksen Observatory (KHO) in Svalbard, Norway.

Even through a layer of low altitude clouds, the camera was able to produce images of unprecedented clarity that revealed something the team didn’t expect – a very faint wave pattern of unknown origin in the lower atmosphere resembling what is known as an "airglow."

Airglow is a natural optical phenomenon involving the very weak emission of light by the Earth's atmosphere. It was already known that airglow could be caused by various processes in the upper atmosphere, including cosmic rays striking the upper atmosphere, or chemical reactions, such as oxygen and nitrogen reacting with hydroxyl ions. However, the wave pattern’s appearance at the same time as the aurora has led the researchers to believe it may also be caused by a previously unknown source. If confirmed, it would be the first time that airglow has been associated with auroras.

“After the January CME, we think we saw an auroral-generated wave interaction with airglow,” said Sigernes. “Our new all-sky camera opens up new frontiers of discovery and will help in the detection of auroras and the understanding of how our Sun impacts the atmosphere here on Earth. Additional development and commissioning will also hopefully verify our intriguing first results.”

Details of the NORUSCA II camera and the results from its first images were published this week in the Optical Society’s (OSA's) open-access journal Optics Express.

Source: The Optical Society

4 comments
Bruce H. Anderson
The LHC in Switzerland discovers what may be new particles, then up in Norway they find new phenomenon in auroras. It seems like the more we learn, the more we learn that we don't know as much as we thought we knew. It must be an exciting time in science.
Gary Fisher
One of the pleasures of living in Michigan and other northern-tier states is the view we get of the aurora borealis. We've had some which filled the sky, from directly overhead to the northern horizon, with beautiful, boiling bands of violet and red as well as the usual shades of green, nothing less than breathtaking. It will be exciting to learn more about this awesome phenomenon.
Daisy Liddell
This is truly a great phenomenon! Absolutely amazing! Thanks for sharing!
Amanda Fleming
NORUSCA II camera is indeed great! I never thought there would be such thing as this. So incredible. I feel so blessed to see all these photos here. So amazing! Thank you so much for sharing all these marvelous proofs of the earth's aurora.