Why Earth has no magnetic field?

Real magnetic field is inversely proportional to the distance cubed. But the imaginary Earth's magnetic field measured near the poles is 0.65 gauss and near the equator is 0.2 gauss.

A compass floating on water would point toward the imaginary Earth's magnetic poles, but would not move toward them.

A compass floating on water in a real magnetic field will move and point toward the magnetic poles. 

The fact is sun's rays move westward around the Earth, creating a weak electric current that constantly moves around the Earth. That induces compasses point north also creates polar lights at night. 

Compasses and sunlight

Compass needles float on still water, they both point north, but they don't move north, why is that?

If one assumes that Earth's magnetic pole at the North Pole causes a compass to point north, then it will also cause a floating compass to move north.

The fact is that the compass points in a direction perpendicular to the weak westward current around the Earth caused by moving sunlight energy, not the Earth's supposed magnetic field.

This weak westward current becomes stronger as it approaches the poles, due to the smaller circumference that produces auroras at night. the smaller circumference that produces auroras at night.