jovian-explorer / sun

Coronal Radio Sounding experiment results for Solar Wind flow speeds from the Indian Mars Orbiter Mission

Coronal Radio Sounding experiment results for Solar Wind flow speeds from the Indian Mars Orbiter Mission -

The complexity of the near Sun solar wind has been showcased by the first occultation measurements using radio signals from a spacecraft. The fluctuations in radio frequency recorded during conjunction events can provide insight into plasma turbulence in the solar wind. In 1965, the Mariner IV spacecraft used radio occultation to measure the atmosphere of Mars, using the technique of observing changes in phase, frequency, and amplitude of radio signals as they pass through the atmosphere. In this paper, we demonstrate the applicability of the Doppler method as a means of observing the Solar corona and wind. The period of observation for this study is from October 2 to October 14, 2021, with the heliocentric distance between 5 - 9 $R_\odot$. The velocity for the stipulated distance and time period is obtained in the range of 112-260 Km/s. We also present a comparison with the different electron number density models derived in the previous studies with the profiles derived from our study by using data collected during the Indian Mars Orbiter Mission in October 2021, received at the Indian Deep Space Network, Bangalore.

Table of contents

• MOM - This folder contains all of the code, data, and the results associated with my thesis project which involved using the radio occultation data recorded by the Indian Mars Orbiter Mission in October 2021 during the Mars Solar conjunction.

  • Aditya_L1 - During the period of my thesis year, I had gone to the Third workshop by the Aditya-L1 support cell, which was organised by ARIES Nainital to educate the scientific community about the ISRO's upcoming Aditya-L1 mission, from 25th to 28th Feb 2023 at IIT-BHU.

  • Akatsuki - This directory contains the documents related to the files generated by the Japanese Akatsuki probe orbiting Venus. The way Akatsuki and MOM record data is fundamentally the same, and acts as a good practice dataset for anyone interested to work with MOM data.

  • Books - This contains some of the books I used while working on my thesis project. Others I could not upload due to the size constraints, but contact me, and I'll share them with you. If possible, buy/loan the books using the proper channels.

  • Code - This is the heart of everythin I did in my thesis year. It contains all the codes to generate all the figures and results I have mentioned in my thesis, as well as in the currently under preparation paper.

    • 50yearplot - Contains the data and code to plot the comparison of measurements of Solar wind from 1971 to 2022.

    • ACE_SWASTI - Code to plot the results obtained from the SWASTI- solar wind framework to compare our findings.

    • MOM_OCCULTATION_DATA - Data obtained from the Mars Orbiter Mission, which is used in this study.

    • OMNI - Data from OMNI satellite (NASA) for the period of the occultation event.

    • PSP - Data from the Parker Solar Orbiter, including its positioning, as well as other data.

    • help

    • main-code - Folder with the main code used for obtaining the results given in my thesis, as well as the paper draft in progress.

    • model-equations - Model equations used for comparisonss between the different plasma frequency models.

    • position-modelling - Code for modelling the position of the spacecrafts involved in this study, as well as the planets in the Solar system.

  • ENLIL - The numerical code ENLIL (Sumerian god of wind and storms) is a research tool for simulations of corotating and transient solar wind disturbances. The physical model is based upon the ideal magnetohydrodynamic (MHD) description and the numerical scheme is an explicit high-resolution TVD Lax-Friedrichs scheme. Corotating Solar Wind Disturbances (CSDs) and Transient Solar Wind Disturbances (TSDs) are two types of disturbances that occur in the solar wind, the stream of charged particles flowing from the Sun.

    CSDs are a slow and relatively long-lasting disturbance in the solar wind, caused by the rotation of the Sun. The solar wind plasma rotates with the Sun, which produces a spiral pattern of alternating high- and low-speed streams of particles. These streams can cause variations in the Earth’s magnetic field and can lead to geomagnetic storms and auroral displays.

    TSDs, on the other hand, are fast and short-lived disturbances in the solar wind, caused by explosive events on the Sun such as solar flares and coronal mass ejections (CMEs). These events can cause sudden changes in the solar wind’s speed, density, and magnetic field, which can in turn lead to geomagnetic storms and other space weather effects. Both CSDs and TSDs can have significant impacts on the Earth’s space environment and technological infrastructure, including communication systems and power grids. Studying these disturbances is an important area of research for understanding the behavior of the Sun and its effects on the Earth.

  • Other_docs - Contains miscellaneous files involved in the project.

  • Pictures - Contains the plots/figures.