Question

Why can you see Polar lights only in higher latitudes?

Answer 1

The magnetic field of the Earth is fairly weak on the surface. As the planet Earth is almost 8,000 miles in diameter, so the magnetic field has to travel a long way to affect your compass. That is why a compass needs to have alightweight magnet and a frictionless bearing. Otherwise, there just isn't enough strength in the Earth's magnetic field to turn the needle.But at the very core of Earth's core, the pressure is so great that this super hot iron crystallizes into a solid. Convection caused by heat radiating from the core, along with the rotation of the Earth, causes the liquid iron to move in a rotational pattern. It is believed that these rotational forces in the liquid iron layer lead to weak magnetic forces around the axis of spin.[This is a working theory currently making the rounds now.]For Further details refer Magnetosphere and Electromagnetic theory

Answer 2

 opens the door to solar wind plasma entering the magnetosphere – Earth’s magnetic ‘bubble’.

The ultimate result can be colourful displays in the night sky known as the Northern or Southern Lights, produced when the particles are channelled along Earth’s magnetic field lines and strike atoms high in the atmosphere.

The interaction with oxygen atoms results in a green or, more rarely, red glow in the night sky, while nitrogen atoms yield blue and purple colours.

Normally, the main region for this impressive display is the ‘auroral oval’, which lies at around 65–70 degrees north or south of the equator, encircling the polar caps