Cluster watches Earth's leaky atmosphere

Aug 28, 2008
This artist's impression shows electrically charged oxygen, hydrogen and helium atoms (ions) leaking into space from the Earth atmosphere, over the poles. ESA's Cluster mission discovered that this accelerated escape is driven by changes in direction of the Earth own magnetic field. Credits: NASA/ESA

Oxygen is constantly leaking out of Earth’s atmosphere and into space. Now, ESA’s formation-flying quartet of satellites, Cluster, has discovered the physical mechanism that is driving the escape. It turns out that the Earth’s own magnetic field is accelerating the oxygen away.

The new work uses data collected by Cluster from 2001 to 2003. During this time, Cluster amassed information about beams of electrically charged oxygen atoms, known as ions, flowing outwards from the polar regions into space. Cluster also measured the strength and direction of the Earth’s magnetic field whenever the beams were present.

Hans Nilsson, Swedish Institute of Space Physics, headed a team of space scientists who analysed the data. They discovered that the oxygen ions were being accelerated by changes in the direction of the magnetic field. “It is a bit like a sling-shot effect,” says Nilsson.

Having all four Cluster spacecraft was essential to the analysis because it gave astronomers a way to measure the strength and direction of the magnetic field over a wide area. “Cluster allowed us to measure the gradient of the magnetic field and see how it was changing direction with time,” says Nilsson.

Before the space age, scientists believed that Earth’s magnetic field was filled only with particles from the solar wind, the constant sleet of particles that escapes from the Sun. They thought this formed a large cushion that protected the Earth’s atmosphere from direct interaction with the solar wind.

“We are beginning to realise just how many interactions can take place between the solar wind and the atmosphere,” says Nilsson. Energetic particles from the solar wind can be channelled along the magnetic field lines and, when these impact the atmosphere of the Earth, they can produce aurorae. This occurs over the poles of Earth. The same interactions provide the oxygen ions with enough energy to accelerate out of the atmosphere and reach the Earth’s magnetic environment.

The Cluster data were captured over the poles with the satellites flying at an altitude of anywhere between 30,000 and 64,000 kilometres. Measurements taken by earlier satellites during the 1980s and 1990s showed that the escaping ions were travelling faster the higher they were observed. This implied that some sort of acceleration mechanism was involved and several possibilities were proposed. Thanks to this new Cluster study, the mechanism accounting for most of the acceleration has now been identified.

At present, the escape of oxygen is nothing to worry about. Compared to the Earth’s stock of the life-supporting gas, the amount escaping is negligible. However, in the far future when the Sun begins to heat up in old age, the balance might change and the oxygen escape may become significant. “We can only predict these future changes if we understand the mechanisms involved,” says Nilsson.

For now, Cluster will continue collecting data and providing new insights into the complex magnetic environment surrounding our planet.

An assessment of the role of the centrifugal acceleration mechanism in high altitude polar cap oxygen ion outflow by H. Nilsson, M. Waara, O. Marghitu, M. Yamauchi, R. Lundin, H. Rème, J-A. Sauvaud, I. Dandouras, E. Lucek, L. M. Kistler, B. Klecker, C. W. Carlson, M. B. Bavassano-Cattaneo, and A. Korth, is published in the journal Annales Geophysicae, 26, 145-157, 2008.

Provided by ESA

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3.3 / 5 (7) Aug 29, 2008
G A S P ! ! ! !
1.2 / 5 (5) Aug 29, 2008
Ok, another prediction of the electric universe has been shown to be true.
not rated yet Aug 29, 2008
So its just a coincidence that there are oxygen ions emitted from the sun which strike the earth and spiral along the magnetic fields hitting the pole? It is the oxygen in the atmosphere that escapes.
1 / 5 (5) Aug 29, 2008
im with seanpu electric, wouldn't it be great.
2 / 5 (4) Aug 29, 2008

Lets hope the media doesn't hear about this... We will have to figure out how to stop the leak if they do.
1 / 5 (1) Aug 29, 2008
Honestly, I don't seen anything new here other than there is an instrument measuring something and it looks like the measurement is a little larger than we thought it would be. It pretty much explains everything I've always heard about the sun getting bigger.

Anyone know what is actually new about this?
1 / 5 (2) Sep 01, 2008
CaptSpaulding, news is only that it is confirmed with some space craft that the earth's atmosphere leaks.

that was a prediction of the electric universe theory.

it would also be news that particles of that which leaks from the earth are also microbes and bacterial spores. thats a prediction of Cosmic Ancestry/Panspermia theory.

But these two have not be considered by the authors of the article nor those that wrote the physorg text.
not rated yet Sep 07, 2008
Its very strange, to me, how the more we learn about the natural processes of our world and beyond, the more we live in fear. Part of me wonders if we will die of stress and high blood pressure from worry before we die from any natural processes that have gone on for thousands, millions, or billions of years. *shrugs* Not saying the knowledge is bad. It's very intriguing and opens up the imagination to me. Just an observation i suppose.

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