When Swarm met Steve

via Tallbloke’s Talkshop
http://ift.tt/1WIzElD

Quote: ‘Flying through Steve, the temperature 300 km above Earth’s surface jumped by 3000°C’.

Thanks to social media and the power of citizen scientists chasing the northern lights, a new feature was discovered recently, as ESA reports.

Nobody knew what this strange ribbon of purple light was, so … it was called Steve. ESA’s Swarm magnetic field mission has now also met Steve and is helping to understand the nature of this new-found feature.

Speaking at the recent Swarm science meeting in Canada, Eric Donovan from the University of Calgary explained how this new finding couldn’t have happened 20 years ago when he started to study the aurora.

While the shimmering, eerie, light display of auroras might be beautiful and captivating, they are also a visual reminder that Earth is connected electrically to the Sun.

A better understanding of the aurora helps to understand more about the relationship between Earth’s magnetic field and the charged atomic particles streaming from the Sun as the solar wind.

“In 1997 we had just one all-sky imager in North America to observe the aurora borealis from the ground,” said Prof. Donovan. “Back then we would be lucky if we got one photograph a night of the aurora taken from the ground that coincides with an observation from a satellite. Now we have many more all-sky imagers and satellite missions like Swarm so we get more than 100 a night.”
. . .
Prof. Donovan said, “As the satellite flew straight through Steve, data from the electric field instrument showed very clear changes.
The temperature 300 km above Earth’s surface jumped by 3000°C and the data revealed a 25 km-wide ribbon of gas flowing westwards at about 6 km/s compared to a speed of about 10 m/s either side of the ribbon.

“It turns out that Steve is actually remarkably common, but we hadn’t noticed it before. It’s thanks to ground-based observations, satellites, today’s explosion of access to data and an army of citizen scientists joining forces to document it.

“Swarm allows us to measure it and I’m sure will continue to help resolve some unanswered questions.”

Full report here [plus link to higher-res picture of ‘Steve’].