(Original post by uthred50)
This is an excellent question, and particularly so coming from someone who isn't even doing A Level Geography yet.
A brief introduction - I'm a Study Helper on this forum and my degree is in geography, and I've done my fair share of climatology!
The short answer to your question is that the Earth's magnetic field is indeed believed to have some influence on weather and climate, but climatology is a complicated business and studies on this topic only began relatively recently (we are really talking within the last decade), so the details are subject to conjecture.
As Lee mentioned above, the mechanism is linked to cosmic rays. Cosmic rays are facinating things in their own right (I'll leave you to scout wikipedia on that topic before I derail too far into astrophysics!) His explanation of that is correct: Cosmic rays give rise to more ions (charged particles) in the atmosphere, which attract water molecules and the clumps that form condense into water droplets, which in turn, given enough volume, become clouds. In terms of the day-to-day effect on weather, the consequences of this are probably quite small. However, from a climatic point of view (i.e. longer-term trends) it could have significant impact (although I cannot emphasise enough how divisive this is - experts in the field disagree hugely with one another).
The thing with a mouthful of a name that we call Galactic Cosmic Ray Climate Theory is a controversial challenger to the mainstream view that carbon dioxide is the principal factor in global warming. The basic premise is that more cloud cover means more reflection of inbound solar radiation which means a cooler Earth, so conversely, fewer cosmic rays means fewer clouds, which therefore contributes to warming.
This is where the magnetism comes in. A higher geomagnetic dipole moment causes a lower cosmic ray flux. Without going into too much physics, the geomagnetic moment is a property of a planet that is directly proportional to the strength of the planetary magnetic field (so in short, stronger field=fewer rays=less precipitation and more warming).
Where's the evidence?
Henrik Svensmark is the man behind GCR climate theory, and he's written a book called 'The Chilling Stars' to explain himself. Svensmark was mainly concerned, I believe, with magnetic changes around the sun (as opposed to the Earth's bipole moment), but nonetheless he suggested the link between cosmic rays and global warming.
Fleitmann et al. published a paper in the journal Science in the early 2000s that recorded some data from stalagmites in Oman, and Wang et al. published another one not long after based on some in China, and both of them combined provide quite a good proxy for low-lattitude precipitation over the past 5000 years or so (second half-ish of the Holocene). So towards the end of the last decade, a couple of guys called Knudsen and Riisager took that data and compared it to geomagnetic dipole movement and found a correlation between changes in the moment and precipitation variability - variability that cannot be explained by CO2 variation over the same time period.
Thanks Uth, this is very helpful. I have heard of Henrik Svensmark, I was reading part of his paper on his theory. The reason I asked this particular question was because I'm taking part in a competition for young minds. The competition is to use or produce a viable experiment that could be carried out via the International Space Station. After a little research I wondered if the magnetic field did indeed have an affect on Earths climate and weather.
Myself and a friend plan to use an infra-red camera and a normal 10 megapixel camera facing the Earth from the cupola module, aboard the ISS. A magnetometer implanted on a small computer will also be used. Throughout the day as the ISS passes over different parts of the worlds, photos will be taken by the infra-red and normal camera, at the same time readings will be taken via the magnetometer. The magnetometer of course the measure the strength of Earths magnetic field as that specific point. Once the data is then transferred back to Earth, the photos will be pared with the data taken from the magnetometer.
As Lee said, the magnetic field does affect the number of cosmic rays hitting bodies of water.
I will look for specific cloud formations, temperatures and specific weather, in an attempt to determine whether the magnetic field does in fact have any major affect on weather and climate.
I understand this is an 'out there' idea, but it has to compete with ideas such as just taking readings of the radiation within the space station. The judges want to see unique ideas, outside the box ideas, a practical idea( could it actually be used on the space station) and the usefulness of the idea, as in could it help people on Earth, would it help us understand something about the environment, and could viable data be gathered.
I simply want your opinion on whether this idea is stupid or useless, and is there any other studies that have been carried out, bounding my observation useless?
Also the sensors that we can use are:
barometric pressure sensor
Could any of these other sensors help in acquiring more accurate results?