Zonal velocity of the equatorial plasma bubbles over Kolhapur, India
- 1Earth and Space Science Laboratory, Department of Physics, Shivaji University, Kolhapur, India
- 2Medium Frequency Radar, Indian Institute of Geomagnetism, Shivaji University Campus, Kolhapur, India
- 3Indian Institute of Geomagnetism, New Panvel, Navi Mumbai, India
- 4National Atmospheric Research Laboratory, Gadanki, India
- 5Centre for Materials for Electronics Technology (C-MET) Hyderabad, 500051, India
- 6Universidade do Vale do Paraiba (UNIVAP), São José dos Campos, São Paulo, Brazil
Abstract. This paper presents the observations of zonal drift velocities of equatorial ionospheric plasma bubbles and their comparison with model values. These velocities are determined by nightglow OI 630.0 nm images. The nightglow observations have been carried out from the low latitude station Kolhapur (16.8° N, 74.2° E; 10.6° N dip lat.) during clear moonless nights. Herein we have presented the drift velocities of equatorial plasma bubbles for the period of February–April 2011. Out of 80 nights, 39 showed the occurrence of equatorial plasma bubbles (49%). These 39 nights correspond to magnetically quiet days (ΣKp < 26). The average eastward zonal velocities (112 ± 10 m s−1) of equatorial plasma bubbles increased from evening sector to 21:00 IST (Indian Standard Time = Universal Time + 05:30:00 h), reach maximum about 165 ± 30 m s−1 and then decreases with time. The calculated velocities are in good agreement with that of recently reported values obtained with models with occasional differences; possible mechanisms of which are discussed.