Figure 6From: Space weather effects on the low latitude D-region ionosphere during solar minimumAverage values of nighttime and daytime signal amplitudes. These are for period 12 to 18 December 2006 for NWC and NPM. A reasonable decrease in the average daytime and nighttime signal strength on 15 December (main phase of storm) is shown using shaded regions which can be attributed to the geomagnetic storm of 14 to 16 December 2006.Back to article page