Conversely, the effects on reception of the tilting ionospheric layers at the twilight period are longer at the higher latitudes, where the rate of change is slower than at the equator where the width of the twilight zone are narrow. The transmitting frequency, the skywave angle, the length of the skip zone and the groundwave can also affect reception conditions. There is little that you can do when propagation conditions adversely affect reception. An antenna not only picks up radio transmitters but also background noise. There are in fact various types.
Galactic noise is one example, the sun being the main source.
Up to about 100 MHz, inter-stellar noise is also present. Alongside that we have atmospheric noise. This is partly caused by the approximately 30,000 thunderstorms that occur each day across the globe. All the lightning produced adds to the background noise, though the level does depend on where you live. Listeners in the tropical zones of the world suffer much more from this type of interference.