[P-EM11] 系外惑星

[PEM11-P14] The dynamic hierarchy of ocean-forming factors during the evolution of planets: introduction to a conceptual model

*Balazs Bradak¹ (1.Kobe University, Faculty of Oceanology)

キーワード：exoplanets, astrogeology, extraterrestrial oceanography, dynamic hierarchy, surface ocean formation

Various planetary bodies with surface oceans, which may harbor life and provide habitat for biological evolution, is one of the main targets of exoplanetary studies. Finding key astronomical and planetary parameters which may influence the formation of the surface ocean, and especially determining the importance of those parameters in its complex is one of the main challenges of extraterrestrial oceanography. To simplify those complex processes, two main components of surface ocean formation were investigated, such as i) the origin of water on/in planetary bodies, and ii) the persistency of the planetary atmosphere. Considering those two components, the type and age of the host star, number of planets in the solar system, semi-major axis, eccentricity, planetary mass, planetary radius; and insolation/solar irradiation were selected as parameters that may determine the probability of surface ocean formation (and are accessible in exoplanetary databases).
Despite their possible role in surface ocean formation, the determination of the importance, and dominance of certain parameters over others feels like a nearly impossible task due to the changing influence of the ocean-forming factors during the evolution of the planetary body. Such a dilemma may be resolved by the application of dynamic hierarchy. Dynamic hierarchy has been applied in various fields of science, especially but not limited to data and social sciences (e.g., Maslow-Krech model), and may describe well the changing dynamics between various parallel appearing and interacting factors/parameters, and their intensity in surface ocean formation during the evolution of the planetary body.