Index Plots

The lines in the chart below show the 10cm flux (squares) and the T index for the northern hemisphere (diamonds) and southern hemisphere (circles).

The bar graph shows the planetary A index. Red bars indicate disturbed days (Ap >= 25), yellow bars moderately disturbed days (16 <= Ap < 25) and green bars quiet days (Ap < 16).

During summer/equinox periods, an ionospheric depression response can often be seen on the days following geomagnetically disturbed days. This is indicated by a dip in the T index plots.