In the past decade there has been growing interest in the investigation of plasma bubble (PB), associated irregularities, which often profoundly impact satellite communication and navigation systems and produce ionospheric scintillations. The basic mechanism of generation and development of equatorial spread F (ESF) is the gravitational Rayleigh-Taylor instability. The trans-ionospheric signal scintillation causes considerable communication hazards at a wide range of frequencies and hence is of much practical interest. In the present study we have investigated the effect of geomagnetic storm on the low latitude ionospheric scintillation for the 03 August 2010 storm at Varanasi (25.30°N, 82.99°E), India. © 2011 IEEE.