Equatorial Plasma Bubble Onset During Strong and Weak Neutral Winds Over Southeast Asia

Equatorial plasma bubbles (EPBs), which are depletions in the ionosphere disrupting radio waves, exhibit complex dynamics influenced by neutral winds. The present study aims to investigate the relationship between the onset of EPBs and the velocities of neutral winds. The onset of EPBs was determined from the rate of the Total Electron Content Index (ROTI) keogram obtained using Global Positioning System (GPS) data over the Southeast Asia sector. Meanwhile, thermospheric neutral winds were measured using a Fabry-Perot interferometer (FPI), and the height of the F layer was acquired from an ionosonde, both instruments positioned in Kototabang (KTB), Indonesia. The observations are classified into two cases based on the strength of winds: strong and weak winds on different nights. This study successfully reported the onset time and location of EPBs occurred at 1320 UT (2120 LT) and 100° (500 km) longitude, attributed to pre-reversal enhancement (PRE). We conclude that thermospheric neutral wind makes a significant contribution to the observed onsets of EPBs driven in the zonal direction. Therefore, this finding reinforces past studies that have shown an increase in the height of the F layer could play an important role in determining the onset of EPBs.