During the past few decades, various investigations on nonlinear heating of the auroral region of the ionosphere and problems related to lower ionosphere are resulted in opening up a new dimension towards the study of various physical processes and also on the characteristics of different parameters of Atmospheric Electricity within the middle and lower ionosphere. This book embodies the results of some of the investigations in these areas. Some modeling works have been performed and results are compared with experimental data of other researchers. Some experiments were undertaken based on the own experimental arrangements from Kolkata and Agartala, India centers during disturbed ionospheric and atmospheric conditions and results are presented here. There are other areas to be explored and further studies are contemplated to gather more information. I shall deem my labour amply rewarded if the matters presented in the book prove to be useful and worthy to the scientific communityin this field.