North-south strength of the interplanetary magnetic field✓Ճիշտ պատասխան
Duration of long-delayed echoes
Բացատրություն
Bz is the component of the interplanetary magnetic field along the Earth's north-south axis, and its sign and magnitude decide how strongly the solar wind couples to the magnetosphere. It is not a measure of stability, not a critical frequency, and has nothing to do with the delay of long-delayed echoes.