Broad plasma depletions (BPDs) are bubble-like plasma depletions in the equatorial F region whose longitudinal widths (> 4 degree) are greater than those of regular bubbles. Their occurrence in satellite observations is understood in terms of the uplift of the ionosphere; BPDs are observed when satellites pass through the bottomside of bubbles. However, a merger of bubbles is also suggested as the cause of BPDs. We investigate the origin of BPDs by examining the occurrence climatology of BPDs and its association with vertical plasma motion. Our preliminary results derived from the C/NOFS observations in 2008–2012 show that BPDs occur more frequently during lower solar activity, during higher magnetic activity, and at lower altitudes. BPDs during solar maximum and minimum periods show different behavior. BPDs during solar maximum period occur frequently at premidnight and during the equinoxes and December solstices (for highly geomagnetically disturbed periods). On the contrary, BPDs during the solar minimum period occur predominantly at postmidnight and during the June solstices. The occurrence rates of postmidnight BPDs are positively correlated with AE index and are inversely correlated with 10.7 cm solar radio flux. Low solar activity creates favorable conditions for generating BPDs by thinning the F region. At the solar minimum, the density of the F region’s bottomside changes significantly even with slight altitude shifts, which can be recognized as BPDs. When a geomagnetic disturbance occurs, the eastward electric field can be enhanced at the equatorial F region, and the entire F layer can move upward.