Research Projects

The aim of the proposal is to investigate the Early Morning Ionosphere-Thermosphere System (EMITS) in low and midlatitudes using a diverse variety of observational datasets to fill our knowledge gaps. Our knowledge of the ionosphere-thermosphere (IT) system after midnight hours to post sunrise period is far from complete. It is not clear yet if there is a regular enhancement/suppression of westward electric field in the sunrise period similar in nature to the pre-reversal enhancement occurring around sunset. This is supposed to be fundamental knowledge given eight decades of active ionospheric research. However, it is not the case. A major hurdle in the exploration of early morning ionosphere is the weak plasma densities making ionospheric measurements difficult. Further, measurements of neutral thermosphere parameters are also scarce. The variabilities of EMITS also depend on the important processes like midnight temperature maximum (MTM) and post-midnight ionospheric instabilities. Complicating the understanding of EMITS is the lack of proper understanding of MTM and the post-midnight ionospheric instabilities. Therefore, this proposal investigates these aspects in unison. Three important research questions to be addressed in this proposal are: 1. Are there regular enhancements to the zonal electric field in the sunrise period similar in nature to the sunset period? If it does, what are the characteristics? 2. What are the detailed characteristics and aftereffects of MTM/MPB in the post-midnight and early morning hours? 3. How do the F-region ionospheric instabilities in the low and midlatitudes evolve/decay in the early morning hours? This proposal intends to study these difficult questions through re-analyzing measurements from a selected set of satellites covering data from 1970s to the present, couple of ground based radars and GNSS TEC measurements. Our analysis will be broadly based on the following three approaches that are complementary to one another: (i) statistical analysis, (ii) case studies, and (iii) utilization of pattern recognition and machine learning techniques to handle the large amount of data. Finally, we will compare the widely used empirical model outputs to the measured data along with obtained results. This will test the suitability of models for practical applications and evaluate their accuracy. These questions will be addressed during a period of three years. We also plan to install a multifrequency GNSS receiver from this project, to measure ionospheric TEC at Krea University to help our studies. The instrument will provide useful results even after the completion of the project. Installation of a GNSS TEC receiver will lead to an active atmospheric and space research laboratory in the institution and will contribute to capacity building through undergraduate and PhD student trainings. A JRF will be recruited to support the data analysis of this ambitious project, which may contribute to her/his PhD.