1.There is an electric field between ionosphere and ground, also earth's magnetic field is perpendicular to this E field, hence by poynting theorem integrating E x H across the entire surface of earth gives a great deal of energy flowing west to east.
2. |S| = (E X B)/u0 = (150 V/m X 0.045 T)/(1.25 X10^-6 H/m) = 54,00,000 W/m^2 !!!!!
3. Imagine keeping a copper rod along west-east, will there be a emf induced across the rod's ends ?, i think we can't measure this voltage because even the voltmeter is inside such an energy flow viz., there is no "sink" or "ground" to do the measurements
4.Are earth currents because of soil intercepting this flow partially? all your opinions are welcomed. .