Earth's Atmosphere is Leaking into Space
Written by Nancy Atkinson
Artist impression of ions leaking into space. Credit: NASA/ESA
Oxygen is constantly leaking out of Earth’s atmosphere and into space. Measurements taken by satellites during the 1980s and 1990s showed the escaping ions were traveling faster the higher they were observed. This implied that some sort of acceleration mechanism was involved. Now, new work on data collected by a group of formation-flying satellites called Cluster shows that Earth’s own magnetic field is accelerating the oxygen away. But don't worry, 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.
From data collected from 2001 to 2003, 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 analyzed 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 realize just how many interactions can take place between the solar wind and the atmosphere,†says Nilsson. Energetic particles from the solar wind can be channeled 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 kilometers. The data is helping scientists to understand what might happen in the future. “We can only predict these future changes if we understand the mechanisms involved,†says Nilsson.
Source: ESA
Filed under: Earth, Earth Observation
August 29th, 2008 at 6:18 am
Is there is a tipping point between gravity and mafnetic field acceleration?
August 29th, 2008 at 6:21 am
Update on my previous message: after posting, did what I should have to start with, and searched myself. Googling I found an article from 2001 stating gross loss amounted to 18% of atmospheric oxygen over the course of 3 Gy. But most is reabsorbed, so NET loss is only 2%.
August 29th, 2008 at 7:00 am
marcellus:
I truly and sincerely tell you that you are in denial.
Global warming is a fact moroon. The only controversy is whether it is caused by humans or its a natural event.
Neglegible is time-scale relative. So for your narrow mentality, I bet, oxygen already escaped from your brain.=)
August 29th, 2008 at 7:21 am
The one fundamental fact of science is that anything is possible, to ridicule or overlook a topic or idea is being at the least naive at the most dangerously arrogant..
August 29th, 2008 at 9:23 am
Korjic, the problem I see is that the ions are continually accelerated. That's the hallmark of an electric field, not of a diverging (although we need to watch the terminology, since magnetic fields have zero _divergence_) magnetic field. A magnetic field from a dipole/multipole will fall off between 1/(r^2) and 1/(r^3), thus the force available at large ranges will drop fast and the "magnetic mirror" will not have enough energy to continue the ions' acceleration, so I'm not convinced that it's the mag field itself that is causing the outward acceleration. The mag field's characteristic is to cause synchrotron (spiraling) acceleration. One would have to ask what quality of the earth's time-varying field is causing this outward acceleration, and if its a natural variation, there has to be a relaxation (since the value of the field with altitude various around a value) and thus there would be an opposite (inward) acceleration of the ions. The outward acceleration reported here seems to correspond to the "auroral smokestacks" reported in other articles, which look a lot like electric currents, and which some people called charged particle beams. I hope Michael G. wil check my facts.
August 30th, 2008 at 7:26 am
ed. What is a moroon? Try consuting a dictionary the next time you need to spell.
Global warming (a.k.a. climate change) is a left wing media driven scare tactic.
The Earth does and always has modified its climate over the billions of years in its existance. No doubt the hunter/gatherers that built all those campfires 17,000 years ago caused the last ice age to disappear.
Get a grip.
August 30th, 2008 at 9:47 am
To: Ed, Would you agree that global warming or climate change regardless of its cause, just might be a serious matter? Or do you believe that 'whatever the cause' will correct itself within our life time? Would you also agree that science and government agencies should communicate more to settle the issue of just how serious global warming is or isn't? Or should the world governments 'just forget about global warming?'
August 30th, 2008 at 1:56 pm
Drought, famine, and global flooding are hardly things you need to shrug off with "Get a grip."
Whether global warming is human-caused is still open for debate.
Whether it is happening at all, however, IS NOT.
Even the Bush admin, the most environmentally unfriendly administration in at least 25 years, has admitted that it is happening, although they won't admit to a human contribution.
August 31st, 2008 at 4:43 pm
I agree that there is global warming regardless of its cause. I mean, would you agree that a magnetism exist regardless of its cause? that we need oxygen regardless of its cause? or that light is emitted from a hot tungsten filament regardless of its cause? What kind of question was that? Im sorry, I just didn't understand what you said.
I haven't mentioned government involvement at all.
August 31st, 2008 at 4:51 pm
And mercellus,
"Global warming (a.k.a. climate change) is a left wing media driven scare tactic."
there is no point in discussing this topic with you. You are just a conspiracy theorist. You probably still believe that the moon landing was a hoax and is made of cheese. Come on.
If you are going to argue that I dont know how to spell moron then at least put a citation of a peer review journal that backs up the comment you posted.
August 31st, 2008 at 7:01 pm
We should accelerate this process every where we find atmosphere or oxygen so the interstellar space is saturated as such and we can just float to our very own star system where the melting glaciers are made of kool aid ,suns made of cheetos. Oceans of refined hydrocarbons and yes moonmarts full of burgain or we could listen to Demliberals? and check our tires till the end of times.
September 1st, 2008 at 11:07 am
The Republicans have been sneering about the check your tire pressure comment from Obama - but that's mostly because they don't understand physics. Or have any grasp of common sense.
Ask any NASCAR mechanic - tire pressure matters for MPG.
AAA auto club recommends you keep your tires well inflated for optimum performance and miles per gallon too.
It seemed to me like a logical suggestion to make that can save people some cents now.
Whereas the Republican solution, as always, is trying to swat a fly with a bazooka - building thousands of off-shore drilling rigs.
But what they won't tell you is that these rigs would take 25 years before they produced any significant quantities of oil, and * even then * they would not lower the cost of gasoline because by that time the demand will have skyrocketed and the extra supply will be just a drop in the bucket.
But I guess people like grand, expensive, wasteful engineering projects more than having to do two seconds of upkeep on their car. God we're lazy.