Equatorial plasma bubbles for solar maximum & moderate year of the solar cycle 24.

The fluctuations in the electron density of the F-region in the ionosphere as compared to the background electron density are the sign of plasma irregularities which is a well-known phenomenon. They occur during post-sunset hours and degrade ionospheric radio wave communication majorly the navigation signals. To explore the features of equatorial plasma bubbles (EPBs) over the Indian region throughout the solar maximum year 2014 and the solar moderate year 2017, we have examined day and night hours plasma irregularities from Defense Meteorological Satellite Program (DMSP) with spacecraft as F15 with total crossings as 9698. From the total crossings, 1115 crossings were obtained with EPBs degrading the communication and navigation signals. The distribution of EPBs was studied monthly, seasonally, and longitudinally for the solar maximum and moderate years which has given significant results. We have also analyzed the occurrence of EPBs during the geomagnetic storms with Disturbed storm time index (Dst) ≤ -100 nT occurred in the solar maximum and moderate years. We have observed that the regular occurrence of EPBs was there during the initial and main phase but smoothens up in course of the recovery phases of the storm. These results are discussed with those of earlier results and are in good agreement too. The observed inferences will help to improve the telecommunication sector in the Indian region. [ABSTRACT FROM AUTHOR]