The Plasmasphere

Most of the mass of particles in server sky orbits is cold (<1eV) plasma, in the upper fringes of the atmosphere. The total mass of these particles is small. This plot shows density versus distance.

This plot is modified from http://plasmasphere.nasa.gov/media/meridianswing.html

orbit	Radius	L_min	L_max	Dens_min	Dens_max	Volume	Mass
m288	12789 km	1.93	2.14	4500/cm³	7000/cm³	1.8e12 km³	17000 kg
m360	14441 km	2.19	2.42	2500/cm³	4000/cm³	2.6e12 km³	14000 kg
m480	16756 km	2.55	2.79	1200/cm³	2500/cm³	3.5e12 km³	11000 kg
Earth						1.1e12 km³	6e24 kg
Troposphere						8e9 km³	5e18 kg

A few thousand tons of thinsats will vastly increase the number of coulomb scattering centers.

MoreLater

The magnetosphere

The dipole field at the equator is 31000nT. A geomagnetic storm changes this by depositing a westward ring of electric current, which induces a negative change in the field:

-30nT to -50nT	weak storm
-50nT to -100nT	moderate storm
> -100nT	intense
> -300nT	"a few times per solar cycle

Shrivjer and Siscoe "Heliophysics" pp265 Cambridge 2010
Also see www.nerc.com/files/GMD_Workshop_Report_April_2011.pdf (chair Don Watkins BPA)