ACT Question for January 8th
As the Sun's activity increases, the number of sunspots increases, as does the flux (flow rate across a 1 m2 area) of radiation and of charged particles that Earth receives from the Sun. The figure below shows Ap, a measure of the activity of Earth?s magnetic field. Ap increases as the flux of charged particles Earth receives from the Sun increases.
A geomagnetic storm in Earth's magnetic field is indicated by an Ap greater than or equal to 30 nT. According to the Figure, a geomagnetic storm occurred at some time during each of how many years, if any, of the 13-year period?