From the UK Telegraph – source link
The protective bubble around the sun that helps to shield the Earth from harmful interstellar radiation is shrinking and getting weaker, NASA scientists have warned.
By Richard Gray, Science Correspondent
Last Updated: 9:23AM BST 19 Oct 2008
New data has revealed that the heliosphere, the protective shield of energy that surrounds our solar system, has weakened by 25 per cent over the past decade and is now at it lowest level since the space race began 50 years ago.
Scientists are baffled at what could be causing the barrier to shrink in this way and are to launch mission to study the heliosphere.
The Interstellar Boundary Explorer, or IBEX, will be launched from an aircraft on Sunday on a Pegasus rocket into an orbit 150,000 miles above the Earth where it will “listen” for the shock wave that forms as our solar system meets the interstellar radiation.
Dr Nathan Schwadron, co-investigator on the IBEX mission at Boston University, said: “The interstellar medium, which is part of the galaxy as a whole, is actually quite a harsh environment. There is a very high energy galactic radiation that is dangerous to living things.
“Around 90 per cent of the galactic cosmic radiation is deflected by our heliosphere, so the boundary protects us from this harsh galactic environment.”
The heliosphere is created by the solar wind, a combination of electrically charged particles and magnetic fields that emanate a more than a million miles an hour from the sun, meet the intergalactic gas that fills the gaps in space between solar systems.
At the boundary where they meet a shock wave is formed that deflects interstellar radiation around the solar system as it travels through the galaxy.
The scientists hope the IBEX mission will allow them to gain a better understanding of what happens at this boundary and help them predict what protection it will offer in the future.
Without the heliosphere the harmful intergalactic cosmic radiation would make life on Earth almost impossible by destroying DNA and making the climate uninhabitable.
Measurements made by the Ulysses deep space probe, which was launched in 1990 to orbit the sun, have shown that the pressure created inside the heliosphere by the solar wind has been decreasing.
Dr David McComas, principal investigator on the IBEX mission, said: “It is a fascinating interaction that our sun has with the galaxy surrounding us. This million mile an hour wind inflates this protective bubble that keeps us safe from intergalactic cosmic rays.
“With less pressure on the inside, the interaction at the boundaries becomes weaker and the heliosphere as a whole gets smaller.”
If the heliosphere continues to weaken, scientists fear that the amount of cosmic radiation reaching the inner parts of our solar system, including Earth, will increase.
This could result in growing levels of disruption to electrical equipment, damage satellites and potentially even harm life on Earth.
But Dr McComas added that it was still unclear exactly what would happen if the heliosphere continued to weaken or what even what the timescale for changes in the heliosphere are.
He said: “There is no imminent danger, but it is hard to know what the future holds. Certainly if the solar wind pressure was to continue to go down and the heliosphere were to almost evaporate then we would be in this sea of galactic cosmic rays. That could have some large effects.
“It is likely that there are natural variations in solar wind pressure and over time it will either stabilise or start going back up.”
(hat tip to Dvid Gladstone)
kim (18:55:38) :
Quibbling a bit, but temperatures have peaked and are now trending down
Trending down like in 1999 and 2000, following the 1998 peak?
Leif – going back to something I said a while ago, and your reply:
egrey : but it’s probably no coincidence that the 20th century’s largest El Nino came at the end of the period of higher solar activity, and the recent La Nina came after solar activity had started dropping.
Leif – Unless you can somehow quantify the probabilities you cannot say that it is ‘probably no coincidence that …’. You can say that you believe that it is no coincidence, but that is quite a different story. There was an even bigger cycle in the 1950s and an even bigger drop in the 1960s. Where were the even bigger Nino/Nina then? Or do you invoke a 40-year lag?
My wording was loose, but I really did mean that it probably was no coincidence – ie. that there were circumstances in which an El Nino was an above-average probability. An item by Joe d’Aleo Pacific Decadal Oscillations Closely Tied to ENSO http://www.intellicast.com/Community/Content.aspx?ref=rss&a=151 shows increased El Nino incidence during warm PDO phases, and increased La Nina incidence during cool PDO phases. The warm/cool PDO phases line up with what I understand to have been the periods of greater/lesser solar activity, so I think my statement was reasonable. Of course, there is no significance to the exact timing of the El Nino in question at exactly the end of the PDO phase – it could have happened at any time during that phase or been smaller, or (less likely) not have happened at all, since we are dealing in probabilities. A graph in d’Aleo’s paper gives a clear picture.
[The d’Aleo item predated my entry by a few days, but I hadn’t seen it at that time. I did expect though that something like what he found was in fact the case.]
kim (18:55:38) :
Quibbling a bit, but temperatures have peaked and are now trending down
My turn to quibble:
peak?http://www.wunderground.com/data/images/latest_monthlytempanomalysmall.gif
kim (18:55:38) :
http://www.wunderground.com/data/images/latest_monthlytempanomalysmall.gif
“Trending down like in 1999 and 2000, following the 1998 peak?”
Not hardly. ’98 peak followed minimum by two years and the trend down immediately thereafter. This time the peak occurred at the beginning of minimum. This minimum is longer by at least a year and deeper and the cooling concurrent.
The next ‘peak’ of consequence will follow 24 max.
egrey (03:52:42) :
The warm/cool PDO phases line up with what I understand to have been the periods of greater/lesser solar activity
The 1940-1950s were cool PDO and solar activity was very high [cycle 19 was the largest ever recorded, without the possible exception of cycle 4 in 1788].
Gary Gulrud (07:25:02) :
“Trending down like in 1999 and 2000, following the 1998 peak?”
The next ‘peak’ of consequence will follow 24 max.
I should have put a smiley on my little joke. But I do agree that there will be a peak some time after 24 max.
Leif
a long-term decline over the 32-year span from 1965 to 1997
Thank you, interesting, maybe we can assume something like that in the north as well.
What about your refutation then,
“Another observational refutation of the GCR hypothesis is that the Earth’s magnetic field has decreased 10% in the last 150 years”
when observations are showing stable or declining GCR?
lgl (10:53:00) :
maybe we can assume something like that in the north as well.
No, the neutron monitors in the North show no such decline. The South pole is unique [as the article said].
What about your refutation then,
“Another observational refutation of the GCR hypothesis is that the Earth’s magnetic field has decreased 10% in the last 150 years”
when observations are showing stable or declining GCR?
Only South Pole show a decline [maybe you can check the temps there?]. The record we have since 1952 is too short to show any increase, although some will take Oulu as an example of increasing flux. Some people say that the high solar activity lately has just exactly canceled the expected GCR increase, but that argument cannot be used in the past back to the Dalton minimum or beyond.
lgl (10:53:00) :
Temp trend at South Pole is cooling:
http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=17257
in spite of the strongly declining GCR flux there. Maybe it is because there are no low clouds there at all. 🙂
lgl (10:53:00) :
“Another observational refutation of the GCR hypothesis is that the Earth’s magnetic field has decreased 10% in the last 150 years”
Lest you think that it is only during the last 150 years, I’ll add that the Earth’s dipole moment has decreased 25% over the last 2000 years. Now, maybe that explains the Hockey Stick very neatly 🙂
lgl (10:53:00) :
At http://www.leif.org/research/CosmicRays-GeoDipole you can see the relationship between the strength of the Earth’s magnetic field and cosmic ray intensity [14C proxy] over the last 10,000 years. The sudden downturn at the right-hand end [now] is called the Suess effect and results from dilution of the atmospheric concentration of 14C from the combustion of fossil fuels [and should be ignored as not related to cosmic rays].
In another thread there was a long discussion about it being warm [in Greenland at least] 6000-7000 years ago. As you can see from the graph, the cosmic ray intensity then was a lot higher that today [because the dipole moment was small]. A high cosmic ray flux should mean cooling according to Svensmark theory. But maybe the GCR theory only posits something about low clouds [and only some of the time, perhaps] and nothing about albedo and temperatures. A direct and major climate driver should operate all the time and should be clear and obvious.
lgl (10:53:00) :
http://www.leif.org/research/CosmicRays-GeoDipole.jpg
I don’t know why WordPress sometimes mauls the URL.
Leif
Temp trend at South Pole
I think I’ll go for their first expl.
“One possible explanation is that the warmer temperatures in the surrounding ocean have produced more precipitation in the continent’s interior, and this increased snowfall has cooled the high-altitude region around the pole”
Much of the low clouds ending up over the continent are probably formed over the ocean anyway.
Leif
In another thread there was a long discussion about it being warm [in Greenland at least] 6000-7000 years ago
Remember the summer insolation on greenland was much higher 6000 years ago, several 10ths W/m2 I think.
Also the ‘averaged-data trap’ is always there. The tropics and the arctic are different planets, even the arctic winter and the arctic summer are different planets and so on, so global averages are dangerous.
A direct and major climate driver should operate all the time and should be clear and obvious.
What if there are several major drivers, and they are interdependent. Then they will not be clear and obvious. For instance, maybe you need both some volcano material (say SO2) and cosmic rays to really boost cloud formation, and maybe that will have less effect if a third factor is changed, hopeless…
It should say ‘several 10s of W/m2’ I guess
lgl (16:11:00) :
What if there are several major drivers, and they are interdependent.
They can’t all be ‘major’. And there certainly are many drivers, including simple oscillations of a complex system, that does not need any driver at all. My criticism of all the wide-eyed enthusiasts that peddle their thing exclusively is precisely that there is no single primary driver and that the various correlations that claim to be obvious are worthless because one can never know what fraction of what is caused by what, until we learn what they all are in great quantitative detail.
As I have said many times, geomagnetic activity is a very nice analogy. In the 1850s this was a great mystery and little progress was made in the next 100 years; even up to 1970 we were mostly ignorant of the basic mechanisms [(s) because there are several]. Today, [almost] everything is crystal clear and we can account for geomagnetic activity in exquisite quantitative detail given only data on the solar wind. And even turn the table and use geomagnetic data from centuries ago to tell us about the solar wind.
lgl (16:11:00) :
Remember the summer insolation on greenland was much higher 6000 years ago, several 10ths W/m2 I think.
True enough, the insolation decreased by 5 W/m2 per 1000 years the last 10,000 years, including the last 1000 years. So, for the past 2000 years, by 10 W/m2. With the increase of GCRs because of the 25% decrease of the dipole moment, those two effects would combine to a very significant steady cooling over the past 2000 years if GCRs were the primary driver, which is not observed.
Leif Svalgaard (17:33:04) :
that there is no single primary driver
I forgot to qualify this: ‘except the orbital changes’. And the [very] slow secular change of solar luminosity over billions of years. It is too tedious to say this all the time, so that is, clearly, understood.
Leif (21:06:19) On 10/29 Trending down after the 1998 peak? Hardly, Leif, you can eyeball better than that. The peak of the natural cycle was early this century sometime in the 2002-2004 area, and clearly trending down in the last couple of years.
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Leif
those two effects would combine to a very significant steady cooling over the past 2000 years if GCRs were the primary driver, which is not observed
What? GCR decreased over 1700 of those 2000 years, there probably was a significant cooling over 1700 years, minimum around 1700 when it was much colder than today, GCR looks very similar to the famous hockey stick.
http://en.wikipedia.org/wiki/Solar_variation
kim (00:30:16) :
Hardly, Leif, you can eyeball better than that. The peak of the natural cycle was early this century sometime in the 2002-2004 area, and clearly trending down in the last couple of years.
Is was also cold for a couple of years after 1998. An a couple of years do not a trend make. anyway, it was meant as a joke, to show how silly it is to say that a couple of years variation makes a climate trend. But, hey, in this game, anything goes, it seems.
lgl (01:30:50) :
What? GCR decreased over 1700 of those 2000 years, there probably was a significant cooling over 1700 years, minimum around 1700 when it was much colder than today, GCR looks very similar to the famous hockey stick.
GCR increased over the 2000 years because the Dipole decreased 25%. On top of this general and significant increase there has been smaller scale variations [the wiggles on http://www.leif.org/research/CosmicRays-GeoDipole.jpg ] that don’t matter much in the grand scheme.
GCR looks very similar to the famous hockey stick
Indeed, if GCRs were the primary driver, the hockey stick would rule and the recent increase in temps would have to be AGW. Many people think so, BTW.
Leif
Indeed, if GCRs were the primary driver, the hockey stick would rule and the recent increase in temps would have to be AGW
What strange argument. The GCR graph is also a hockey stick, rapid decrease after 1700.
http://en.wikipedia.org/wiki/Image:Carbon14_with_activity_labels.svg
I know the last part is not real but Be-10 is showing the same
http://en.wikipedia.org/wiki/Image:Solar_Activity_Proxies.png
lgl (09:55:53) :
I know the last part is not real but Be-10 is showing the same
http://en.wikipedia.org/wiki/Image:Solar_Activity_Proxies.png
The reliable 10Be record stops in 1930 [the ice near the surface is not suitable for the measurements]. So, the 10Be is ‘spliced’ onto the Neutron Monitor record [inverted to 10Be concentration]. This is where the problem creeps in. I have referred to this many many many times, but here goes one more time: http://www.leif.org/research/Comment%20on%20McCracken.pdf
line 90
Leif (09:13:34) Got your point about trends, but I believe in Easterbrook’s thesis about the PDO. You can see it cycle throughout the 20th Century, and it peaked about 2003. That’s the main reason I believe we are in a 20-30 year cooling trend. And yeah, I missed the joke; I’ve run across too many snide comments from warmistas who complain that we skeptics cherry-pick 1998 as a starting point for a trend. My starting point for the new cooling trend is early this century.
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