About us

Group iconTeam Leader: Dr. Kong, Dali

Research Areas

The "Planetary Physics and Magnetohydrodynamics" research group was established in June 2017, based at the Center for Astronomical and Geophysical Dynamics of the Shanghai Astronomical Observatory. The long-term members of the group include Dr. Kong, Dali (Astronomer), Dr. Li, Ligang (Associate Astronomer), Dr. Cheng, Jianxia (Associate Astronomer), Dr. Huang, Chenliang (Associate Astronomer), Dr. Tang, Kai (Associate Astronomer), Dr. Li, Xizhi (Assistant Astronomer), as well as Dr. Lian, Yuchen (postdoc) and Dr. Li, Wenbo (postdoc). Our group focuses on the field of planetary physics, especially the study of planetary fluid mechanics, using a combination of theoretical analysis, numerical simulation, and experimental research methods. The main research directions include:

SHADE
 1. Static Equilibrium Shape and Internal Structure of Rapidly Rotating Planets
    Isolated rotating celestial bodies achieve static equilibrium under the influence of self-gravity, fluid pressure, and rotational centrifugal force. Understanding the fluid static equilibrium structure of planets is the cornerstone for accurately studying various dynamic physical processes within planets, as well as the formation and evolution of planets. With the launch of high-precision deep space exploration programs such as JUNO and Cassini, research on the fluid static equilibrium shape and structure of planets, especially gas giants, has reached a new high. Researchers in this direction include Dr. Kong, Dali, Dr. Li, Ligang, and Dr. Li, Wenbo.

2. Atmospheric Motion of Gas Giants
   
The atmospheric motion of gas giants exhibits a rich array of dynamical characteristics, including global-scale zonal circulation, strong vortices with diameters of thousands of kilometers that persist over long periods (such as Jupiter's Great Red Spot), and intricate turbulent patterns. The deep structure of atmospheric motion on gas giants is a fundamental planetary physics issue that has been continuously studied for a long time and has become an important scientific goal for the Juno and Cassini exploration programs, as well as future Chinese planetary exploration projects. Researchers in this direction include Dr. Kong, Dali, Dr. Li, Ligang, and Dr. Lian, Yuchen.

3. Deep Convection and Magnetic Field Generation in Planets
 
   The existence of an intrinsic magnetic field in planets is a common phenomenon. Planetary magnetic fields are of significant importance to the internal state and external environment of planets. The generation and maintenance of planetary magnetic fields come from complex magnetohydrodynamic processes within the planet, commonly referred to as the "planetary dynamo." The "dynamo" process converts a portion of the planet's internal thermal energy and rotational kinetic energy into electromagnetic energy. The dynamics of this conversion process is a grand fundamental issue in planetary physics, representing a challenging problem at the intersection of mathematics, fluid mechanics, theoretical physics, and computational science. Researchers in this direction include Dr. Kong, Dali.


grid of finite element4. Planetary Magnetic Fields and Plasma Environments
   
The interaction of planetary magnetic fields with the solar wind or other particle environments results in a variety of magnetized plasma activities. The study of plasma waves and electromagnetic wave propagation mechanisms in the magnetized plasma environment surrounding planets is an interdisciplinary field that bridges geophysics, space physics, and planetary physics. The relevant theories and observations not only help us understand the interplanetary environment within the solar system but also serve as an important means for exploring and studying the broader exoplanetary world beyond our solar system. Researchers in this direction include Dr. Kong, Dali and Dr. Cheng, Jianxia.

    5. Computational Planetary Fluid Mechanics
    Research in planetary physics and planetary magnetofluid dynamics has long been closely associated with modern high-performance computing. Three-dimensional magnetofluid dynamics simulations are very challenging, often involving massive computational loads and a strong dependence on high-parallelism, large-scale computing hardware and software environments. China's high-performance computing hardware conditions are already at the international advanced level. Making full use of existing supercomputing resources is an important branch direction of our planetary fluid mechanics research. Researchers in this direction include Dr. Kong, Dali, Dr. Li, Ligang, Dr. Lian, Yuchen, and Dr. Li, Wenbo.


6. Solar Eruptive Phenomena
    Research on solar flares, coronal mass ejections, filaments, prominences, and related eruptive phenomena; multi-wavelength data analysis of solar eruptive phenomena; non-local thermodynamic equilibrium calculations, and radiative transfer. Researchers in this direction include Dr. Cheng, Jianxia.

7. Research on Small Bodies in the Solar System
    A multitude of asteroids and comets are a distinctive category of celestial bodies in the solar system, containing many unsolved mysteries in planetary science and serving as an important pathway to understanding the formation and evolution of the solar system. Observational data of asteroids and comets are becoming increasingly abundant. Research directions for asteroids include: the surface structural characteristics of planets caused by high-speed small body impacts; the low-speed collision and merging process of small celestial bodies in close orbit; the thermal physical properties of small celestial bodies; and the study of the physical properties of asteroids and comets using a variety of observational data (optical, infrared, remote sensing, etc.). Researchers in this direction include Dr. Li, Xizhi.

cartoon Earth
8. Hydrodynamic Escape of Exoplanetary Atmosphere
   
Exoplanets are one of the hottest research fields in astronomy today, and the loss of planetary atmospheres has a significant impact on the evolution of planets, being an essential part of understanding the evolution and distribution characteristics of planets. The transmission spectroscopy method provides the possibility of directly detecting the high-level structure of planets and their escape processes. By constructing hydrodynamic escape models that include non-local thermal equilibrium atmospheres, combined with radiative transfer calculations in the atmosphere, and comparing with the observed transmission spectral characteristics of planetary atmospheres, we can enhance our understanding of the structure of planetary upper atmosphere and escape mechanisms of hot Jupiters. Researchers in this direction include Dr. Huang, Chenliang.

9. Internal Structure Simulation of Terrestrial Exoplanets (Magrathea)
    Terrestrial exoplanets, with their solid or liquid surfaces, are the first choice for the search for extraterrestrial life. The internal structure models of terrestrial exoplanets can calculate their radius and internal density, temperature, and phase distribution based on the given composition of the planet. The tool of internal structure models has a wide range of applications, such as roughly analyzing the internal composition of planets with known mass and radius. Researchers in this direction include Dr. Huang, Chenliang.

In addition, the research directions of the group also include: the free oscillations and dynamic tidal response of planets, the gravitational field signals of large-scale dynamic processes of planets, the long-term evolution of natural satellite systems, and geomagnetic data-based geomagnetic field models and space weather models.

The group is currently supported by the National Natural Science Foundation of China, the Civil Aerospace Technology Pre-Research Project of the Science and Technology Commission of the State Council, the Strategic Pioneering Science and Technology Special Project of the Chinese Academy of Sciences (Type B), and the Hong Kong, Macao, and Taiwan Cooperation Project of the Shanghai Science and Technology Commission. It also serves as a core scientific team member in the Macao Scientific Satellite mission.


Team Leader: KONG Dali

Team Members: LI Ligang, CHENG Jianxia, HUANG Chenliang, TANG Kai, LI Xizhi

Postdoctoral Researchers: LIAN Yuchen, LI Wenbo

Ph.D. Students: CHEN Xiuyu, ZHU Xujiao, WANG Yujie, LI Yixing, XUE Shanshan

Master's Students: TANG Rui, YUAN Xutong, HE Congrui

Former Members:
Postdoctoral Researchers: WANG Yabin, MA Xin

 
2024 Team Group Photo

Back row from left: WANG Yujie, ZHU Xujiao, XUE Shanshan, TANG Ruirui, LI Yixing, CHEN Xiuyu, YUAN Xutong

Front row from left: TANG Kai, LI Wenbo, LI Xizhi, LI, Ligang, KONG, Dali, CHENG Jianxia, LIAN Yuchen, HUANG Chenliang
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