Martian whole atmosphere model and dust activities: Review and prospect

Developing the Martian whole atmosphere model (WAM) helps us understand the Martian land-atmosphere-space coupling comprehensively. In the history of Mars exploration, simulations performed by various Martian atmosphere models played a crucial role in ensuring the success of those Mars exploration emissions. On the other hand, more accurate observations also advance the model development. Realizing the importance of dynamics, physics, and chemistry in Mars aerospace motivated scientists to extend the upper boundary of models from the lower atmosphere to the exobase. At the beginning of the 21st century, the prototype of WAM covering the entire atmospheric region was developed, greatly facilitating the relevant investigation. Mars dust is one of the most critical activities that significantly affect the climate and weather in a wide vertical range and thus pose a considerable threat to the safety of Mars surface detectors. The better simulation of dust activities and their impacts on the atmosphere and space should be one of the critical points in the development of the Martian WAM. This paper reviews the development history of the Mars WAM, outlines its construction methods, summarizes relevant scientific research achievements, and discusses the essential scientific research and engineering value of independently developing the Mars WAM from multiple perspectives. We have selected three advanced Martian WAMs developed by international groups to discuss the relationship between their development and the exploration mission at that time, including the MGCM-MTGCM (Mars GCM coupled with Mars Thermosphere General Circulation Model), the M-GITM (Mars Global Ionosphere-Thermosphere Model), and the Mars PCM (Mars Planetary Climate Model). Then, we briefly introduce how to construct a Mars WAM and stress the key technologies in the model development. Furthermore, a preliminary numerical experiment under standard and high-dusty conditions was displayed, simulated by a coupled model of Mars-WRF and MITM (Mars Ionosphere-Thermosphere Model). The one-way coupled model presents a reasonable thermal structure at 0-300 km heights and illustrates the different effects of dust at different altitudes. This will be an important foundation for developing fully coupled Chinese WAM in the near future. With the approach of the next Mars exploration window in 2028-2030, returning samples will become a key task in international deep space exploration planning. At present, relevant simulation research based on the Mars WAM needs to catch up; only then can the model work play a role in optimizing the scientific value and providing guaranteed services in the next Mars exploration plan. Considering the adverse impact of Martian dust on exploration, e.g., the Zhurong Rover hibernated after experiencing a dust storm, we suggest focusing on the research direction of Martian dust activities. Numerical modeling can help to deepen the understanding of the dust cycle and its effects, such as dust initiation mechanism, dust propagation and dissipation in the atmosphere, and impacts on the Martian atmosphere and space environment. These investigations will promote the development of Chinese Mars WAM. At the present stage, Chinese groups have achievements in modeling studies in the Martian dust and have preliminarily established a WAM framework. There is also a group of scholars in earth sciences who are engaged in WAM's research work. As a result, China has the initial conditions to develop a Mars WAM on its own. The following development and application need to involve the cooperation of planetary, space, atmospheric, and computer science. The development process is bound to drive the comprehensive development of planetary science in China, accumulate experience, and cultivate talents for related research fields.