Magnetosphere-Ionosphere Plasma dynamics in EARth and pLanetary environments (MI- PEARL)
Chief Co-ordinator - Prof. Satyavir Singh & Members
Plasma the 4th state of matter is ubiquitous in our solar system and have been observed in planetary environments such as their ionospheres and magnetospheres. Any variability related to the energy released from the Sun, in the form of photon flux (in the UV, EUV and X-ray bands), solar wind, coronal mass ejections, and solar energetic particles, are known to be the main factor influencing the particle dynamics in the Earth’s ionosphere-magnetosphere coupled plasma system. In-situ measurements of particles and fields from various spacecraft missions have greatly advanced our understanding of fundamental processes, such as charged particle transport, particle acceleration, particle loss, and magnetic reconnection in Sun’s and Earth’s plasma environments.
In the case of other planets in the solar system, solar-driven perturbations also play a similar role in controlling plasma dynamics in their respective ionosphere-magnetosphere system. However, this dynamical control is planet-specific and, in some situations, it is also influenced by the variability of the planet's environment's internal plasma sources. For example, the variability of the plasma originating from one of the Jovian moon Io, dynamically affects the charged particle environment in the Jovian magnetosphere. Further, the configuration of magnetosphere, a protective shield around any planet, is not the same for all the planets. For example, Mars has a weak induced magnetosphere due to absence of its intrinsic magnetic field. On the other hand, Jupiter has a huge magnetosphere that extends up to Saturn. In case of the Earth, it has intrinsic magnetic field but its field strength is gradually decreasing over past several decades. Thus, planetary plasma environments form unique systems to study the particle dynamics in a weak as well as strong magnetic field.
The Sun–Earth system, and the physics it encompasses, is often invoked in the field of planetary sciences in connection with solar wind interaction issues. Our knowledge of the solar wind coupling with the Earth's magnetosphere is far greater than any other planet due to the wealth of available spacecraft observations and the efforts put into their interpretation. While significant progress has been made in understanding wave-particle interaction processes in Earth's magnetosphere, there are still several research gaps that scientists are actively working to address. Some of these gaps include but not limited to:
In situ observations: While multi-satellite missions like MMS, THEMIS, and Cluster have provided valuable data, there are still regions of the Earth’s magnetosphere that remain relatively unexplored for the role of wave dynamical processes. Obtaining in situ multi-spacecraft and multipoint observations by spacecraft from these regions, especially near the wave sources, is crucial for gaining a comprehensive understanding of the role of these waves.
Wave generation mechanisms: Understanding the sources of waves in the magnetosphere and to know how they are generated remains a topic of active research. Identifying the mechanisms responsible for generating specific wave modes (e.g. EMIC waves, solitary waves, lower and upper hybrid waves, Alfven waves, magnetosonic waves, etc.) is essential for understanding the overall wave-particle interaction processes, which may involve multi-step processes in particle acceleration or their loss to the atmosphere.
Unresolved microscale processes: Particle and wave dynamical processes in planetary environments occur on microscale levels, where the spatial and temporal scales are very small. Current observational and modeling techniques may not fully capture these processes. Developing new simulation tools will help in understanding the fine-scale dynamics in the planetary magnetosphere.
Particle population dynamics: The planetary magnetospheres contain different charged particles with a wide range of energies. Understanding how different particle populations interact with various types of waves and how these interactions contribute to particle precipitation or ion outflows is an ongoing challenge. Further, understanding the motion of charged particles in planetary magnetospheres involves added complexities due to different spatial and time scales. There are still unanswered questions: e.g. how motion of charged particles get affected by different solar conditions in Earth’s magnetosphere? How to explain the particle motion in the Jovian magnetosphere which becomes complex due to its large size and the plasma interaction with its moons.
The scientists under the MI-PEARL program proposed to study the following objectives:
1. Investigating energetic particle loss from the Earth’s magnetosphere via wave-particle interactions and its precipitation into high latitude ionosphere using in-situ, ground-based, and low-Earth orbit satellites
2. Understand wave-particle interactions and associated processes like transport, heating, and energization through multipoint observations in Earth’s magnetosphere
3. Study of plasma waves and associated micro- and macro-scale cascading processes in the solar wind, Earth's, and other planetary magnetospheres (Mars, Venus, and Jupiter).
4. Understanding ionosphere-magnetosphere plasma systems in weak Martian and strong Jovian magnetospheres through observations and modelling.
Chief Coordinator : Satyavir Singh
Coordinator(s) : Amar Kakad
Members : Satyavir Singh, Amar Kakad, Bharati Kakad, Remya Bhanu, S. Devanandhan, Chinmaya Nayak, B. Jayashree, T. Sreeraj and students
