Dst index and ROB-TEC products for the period February 25 to March 1, 2014. The red line is the storm onset of the moderate geomagnetic storm on February 27. Top: the Dst index as delivered by the WDC Kyoto Observatory. Bottom: the three time-series extracted from ROB-TEC maps at three different geographic locations shown on Figure 4. The bold line represents the relative differences between the ROB-TEC values and the median from the 15 previous days. The dashed line is the variability of the vTEC estimated in NRT.