The charged particled trapped in the Van-Allen belts around Earth, maybe they affected by the natural Earth's rotational or wobbling motions and their distribution get disturbed and may reflect some radio disturbances or affect the TEC distribution in the ionosphere.
The whole of magnetic phenomenon depend onthe movement of plasma in the radiation belt.
R.G.
Perhaps the question should read like this ;'Are the motion of charged particles trapped in radiation belt affected by the Earth's rotation and its wobbling motion?'
My answer is 'Yes ofcourse;Geomagnetism is evolved due to and consequently regulated by the axial rotation speed and direction which is again greatly influenced by the Sun's gravitation and meteoritic influx into the terrestrial atmosphere as well as the eventual loss of gaseous mass from the extreme outer boundary of exosphere.Again the charged particles coming from cosmos(cosmic rays) are trapped into the radiation belt which is a part of the Earth itself specifically shaped by a very strong interaction between the solar magnetic flux and the terrestrial magnetosphere.Therefore it is a common expectation that motion of trapped charged particles must be affected by the Earth's rotation and its variation
If the question is, 'Whether trapped charged particles in radiation belts are affected by natural rotational motion of the Earth?'....
First note that not all trapped particles are radiation belt particles. Radiation belt is referring to the region having high energy charged particles. The main processes of energization is believed to be Betatron and Fermi accelerations. I am mentioning this because, it appears as if ring current is not due to radiation belt particles but due to lower energy trapped particles. Now coming to the question, I think most of the radiation belts exist in the region that corotates with the earth. Therefore, the effects of natural rotation on the trapped particles, if any is actually present, might be far lesser than that of pitch angle scattering and energetic neutral atom precipitation. Also. when you are generally referring to the trapped particles and not only of radiation belts, then there are pseudo trapping regions as well, from where particles are lost. In addition to these processes, wave-particle interactions act on the trapped particles and scatter them.
I know my answer is not very much in detail and sorry about that. Partly because, I am not an expert in the studies of radiation belts. But I hope the book 'Solar-Terrestrial Environment' by Hargreaves will give better insights in a basic level.
The earth's rotation is very slow compared with the the timescales of trapped radiation (microseconds for gyration, seconds for bounce between mirror points, minutes for drift around the earth) and the periods of precession and nutation are many thousands of years. What is important is the geomagnetic field which is not symmetric as the solar wind compresses it on the day side and extends it on the night side. This leads to diurnal variations as well as large, short-term variations from geomagnetic storms arising from features in the solar wind. On long timescales the earth's field is steadily changing in strength and direction and will reverse in the future. On the timescale of years we see a steady drift which alters the trapped radiation and must be allowed for in designing space systems and planning extravehicular activity on ISS. I agree that Hargreave's book is an excellent source.
As correctly pointed out by C. S. Dyer and Viswanathan Lakshmi Narayanan, first the time scales of rotation and wobbling are much larger than even drift periods (few minutes) of the trapped particles. Therefore, the changes in the magnetic field much larger than drift period will conserve adiabatic invariants and result as no effect in particles on short time scales. However, in thousand years time scale geomagnetic field changes and therefore should alter particle fluxes and energies in the radiation belt. About rotation, inner magnetosphere very much co-rotates with the Earth, so no effect of that. However, the coronation electric field distorts the shape of the plasmasphere (Ref: Basics of Plasma Physics by Baumjohann and Treumann). At the same time, radiation belt dynamics is controlled by external drivel, the solar wind. Mainly outer radiation belt is strongly affected by solar wind and cause transient changes in the particle fluxes and energies. Your question is interesting and even I had this some time ago, some simulation study should be carried out to see how geomagnetic reversal affects radiation belt.
The dynamics of the outer radiation belt is an extremely important issue for geostationary orbit and for the orbits of navigation spacecraft. Short-term increases following geomagnetic storms lead to spacecraft charging which is a major source of anomalies in such spacecraft. For the future of radiation belts I don't think we know what the field will look like during a reversal. We will certainly be less protected from cosmic radiation during this period and aviation will have to take this into account.
The answer given by Theoretical Plasma Physics Experts should be enough. R.G.Rastogi
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