Digantara · Indian Institute of Science Education and Research (IISER), Pune
I am Saikat Majumder, a Space Weather Engineer II at Digantara, where I work on building practical, physics-informed solutions that improve orbit prediction accuracy and space operations safety. I hold a BS-MS Dual Degree in Physics from IISER Pune and bring a strong foundation in solar-terrestrial physics, thermospheric dynamics, and space weather impact analysis. My work focuses on translating the physics of solar and geomagnetic variability into scalable algorithms and validation workflows that support more reliable decision-making for satellite operations. I investigate how space weather affects the upper atmosphere, quantify its influence on satellite drag and trajectory prediction, and develop tools that reduce uncertainty in orbit propagation. I combine domain knowledge with engineering execution to turn space weather effects into actionable operational intelligence. I work extensively with Python and MATLAB and use solar physics and astrodynamics libraries and related scientific tools for analysis, modelling, and visualization. I also bring published research experience across peer-reviewed articles, conference papers and posters in the domains of space weather, astrodynamics and heliophysics, bridging research, engineering, and operational applications. My background combines theoretical understanding and applied space weather engineering, with a demonstrated record of building scalable, reliable space weather solutions that strengthen resilience across the space sector.
During this internship, I worked in the role of a Space Weather Analyst Intern at Digantara Research and Technologies Pvt. Ltd to advance the understanding of upper atmospheric density models for improving the accuracy of orbit prediction. I performed a comparative analysis of empirical density models with truth data to gain a better understanding of the effects of space weather parameters in atmospheric density modelling. This internship provided me with valuable research skills and first-hand industry experience in the space sector which is where I wish to employ my expertise moving forward.
• Introduction to the advanced statistical and AI/ML techniques commonly used in solar physics • Introduction to the ADITYA-L1 mission and its science objectives • Hands-on sessions on imaging and spectroscopic analysis, numerical MHD simulations using basic solar data
Massive eruptions of plasma and magnetic fields from the solar corona, called Coronal Mass Ejections (CMEs) are significant drivers of space weather phenomena and can cause extreme geomagnetic storms if Earth-directed. Therefore, reliable estimates of CME arrival times and a thorough understanding of CME dynamics are crucial for space weather forecasting. If CMEs were to expand adiabatically, their temperature at 1 AU would be about a few degrees of kelvin. However, the observed proton temperatures are as high as a hundred thousand kelvin. This discrepancy suggests that either there is sufficient thermal conduction from the Sun to the CME interior or substantial plasma heating happening inside the CMEs. We examine the first possibility in this work by considering electron thermal conduction. We have computed the CME propagation velocities and electron thermal conduction front velocities for a collection of 38 Earth-directed CMEs using semi-empirical models, remote sensing images from SOHO/LASCO and STEREO/SECCHI coronagraphs, as well as in situ data from WIND spacecraft. The conduction velocities are estimated for purely Spitzer thermal conductivity and two different types of turbulence-modified anomalous thermal conductivities. Comparison between the CME propagation and conduction velocities shows that thermal conduction is much faster than CME propagation for Spitzer conductivity, while it is less fast for Kolmogorov turbulence-modified conductivity. The two speeds become comparable for conductivity modified by Kraichnan turbulence. These results are consistent across all 38 events. This seems to imply that thermal conduction is sufficient to explain the high electron temperature in the CME interior, and thus CME expansion can be modelled as nearly isothermal. We have further calculated the heating rate of electron-proton equilibration and found that it is quite small. Our results, therefore, justify the need for invoking additional heating mechanisms for protons.
Project Instructor: Dr. Prasad Subramanian, IISER Pune Topic: Thermodynamics of Solar Coronal Mass Ejections (CMEs) • Through this project, we investigated the thermal conduction timescales for several ICMEs at various heliospheric distances propagating with different speeds; and compared it with their Sun-Earth propagation timescale to answer if there is a need for internal plasma heating. • Using in-situ observations from Space-borne coronagraphs and probes, the conduction timescales were found to be less than the propagation timescales, which implies that conductive heating processes are undergoing from the solar corona to the ICME interior. This could be a probable reason for the quasi-isothermal behaviour of the ICMEs.
• Participated in the largest meeting of professional astronomers in India and learnt about the exciting new developments and scientific results across various disciplines of Astronomy and Astrophysics. • Attended the ASI 2023 Workshop on the Origin and Evolution of Solar Eruptive Phenomena: Observations, Modeling and Sun-Earth Connection. Interactive sessions ranging from multiwavelength observations, magnetic connections of solar eruptive features to numerical MHD simulations and Sun-Earth connection of solar eruptions were conducted.
• Through the lectures in this workshop, I developed a thorough understanding of the physics of the Sun, its dynamic atmosphere, the large-scale eruptive events, MHD processes in the Sun and the heliosphere, and their connection to space weather. • Learned to analyse and interpret data using multiwavelength study of the solar corona from various instruments onboard Aditya-L1, India’s first space-based observatory to study the Sun. • Through hands-on sessions, I learned to extract spectral and coronagraphic data from the Sun using imaging techniques.