Dynamics, chemistry, and modeling studies in the aviation and aerospace transition zone.

In this review, the concept of the aviation and aerospace transition zone (AATZ), that is, the area between the highest altitude of aviation vehicles and the lowest altitude of space vehicles, is introduced. It is 50-150 km away from the Earth's surface, and the coupling between the AATZ and its upper and lower atmosphere causes complex and unique physical and chemical processes. As a transition zone between space weather and Earth weather, the AATZ has great scientific research value and broad application prospects. Focusing on the dynamics, chemistry, and modeling studies of the atmosphere in this region, we comprehensively analyze and discuss the current research status, current challenges, and future prospects of this region. The propagation, dissipation, and momentum deposition of the atmospheric wave force change the surrounding wind field and temperature structure, forming complex dynamical processes. The mutation enhancement and redistribution of metal atoms and metal ions, as well as the occurrence of airglow, directly or indirectly show the changes in composition and energy transfer caused by complex chemical processes. The modeling studies of the above phenomena are conducive to the deepening of understanding, and the defects of the simulation also reflect the lack of observation on understanding. The discussion in this review encourages more research on the AATZ as well as the development and enrichment of existing observational tools and techniques to fill in the knowledge gaps and enhance the ability to apply the region in the aerospace industry.