講演情報
[PPS04-P30]Investigating the Impact of Atmospheric Variability and Spin-Orbit Configurations on the Climate Dynamics of Proxima Centauri b
*Benjamin Goodsell1 (1.Earth System and Climate Centre)
キーワード：
exoplanet、climate model
This study presents a detailed analysis of the climate of Proxima Centauri b, utilizing a Python-implemented general climate model tailored for terrestrial planet applications. The research explores climate variables including temperature, wind patterns, cloud formation, rainfall, and humidity, to construct a comprehensive climate profile of the exoplanet through different model configurations. These include a range of potential atmospheric compositions, from minimal atmospheres to dense carbon dioxide and nitrogen-rich profile; and various land-to-water ratios are investigated using configurations with differing continental layouts and land fractions. The study also considers the effects of orbital dynamics, addressing scenarios like tidal locking and various spin-orbit values.
While results provided insight into the potential climate of Proxima Centauri b, the model was limited in its ability to produce a greenhouse effect for dense carbon rich atmospheres, but did experience a runaway greenhouse effect for a high pressure nitrogen, carbon dioxide and water atmosphere. The very thin atmosphere model exhibited extreme day-night temperature contrasts exceeding 80 degrees under tidal locking. An Earth-like atmospheric configuration, primarily dominated by nitrogen and oxygen, was used with varying land fractions, to reveal substantial climate sensitivity to surface characteristics: under tidal locking, the quarter-land configuration produced the warmest conditions, albeit on average still below 0 degrees Celsius, and also had the highest relative humidity, strongest precipitation rates, and greatest cloud coverage, while the three-quarters land configuration exhibited cooler temperatures, dramatically reduced humidity, minimal precipitation, and sparse cloud cover. Transitions from tidally locked to non-synchronous rotation generally increased global mean temperatures across all atmospheric models, with the Earth-like atmospheric configuration showing the most pronounced warming in the 2:1 configuration, and land fraction exerting minimal influence on the magnitude of this warming trend. Areas where liquid water could exist were restricted to low latitude areas across all spin-orbit and land fraction configurations, although for the tidally locked configuration this was restricted to the dayside, and for the 3:2 case land covered areas often went below freezing, while in the 2:1 case larger areas of land were above freezing.
The results from this research indicate limits on habitability, including areas that act as refuge to life as we know it; and also reveal limitations with respect to climate modeling for exoplanet applications and acts as a framework for studying other exoplanets with similar characteristics. By advancing our tools for climate modeling and applying them to diverse planetary conditions, we can gain valuable insights into the atmospheric dynamics and potential habitability of distant worlds. The findings highlight the significance of tailored models in exoplanetary research, aiming to bridge the gap between planetary sciences and climatological studies, ultimately offering a pathway to understanding the climatic regimes that might support life in the universe.
While results provided insight into the potential climate of Proxima Centauri b, the model was limited in its ability to produce a greenhouse effect for dense carbon rich atmospheres, but did experience a runaway greenhouse effect for a high pressure nitrogen, carbon dioxide and water atmosphere. The very thin atmosphere model exhibited extreme day-night temperature contrasts exceeding 80 degrees under tidal locking. An Earth-like atmospheric configuration, primarily dominated by nitrogen and oxygen, was used with varying land fractions, to reveal substantial climate sensitivity to surface characteristics: under tidal locking, the quarter-land configuration produced the warmest conditions, albeit on average still below 0 degrees Celsius, and also had the highest relative humidity, strongest precipitation rates, and greatest cloud coverage, while the three-quarters land configuration exhibited cooler temperatures, dramatically reduced humidity, minimal precipitation, and sparse cloud cover. Transitions from tidally locked to non-synchronous rotation generally increased global mean temperatures across all atmospheric models, with the Earth-like atmospheric configuration showing the most pronounced warming in the 2:1 configuration, and land fraction exerting minimal influence on the magnitude of this warming trend. Areas where liquid water could exist were restricted to low latitude areas across all spin-orbit and land fraction configurations, although for the tidally locked configuration this was restricted to the dayside, and for the 3:2 case land covered areas often went below freezing, while in the 2:1 case larger areas of land were above freezing.
The results from this research indicate limits on habitability, including areas that act as refuge to life as we know it; and also reveal limitations with respect to climate modeling for exoplanet applications and acts as a framework for studying other exoplanets with similar characteristics. By advancing our tools for climate modeling and applying them to diverse planetary conditions, we can gain valuable insights into the atmospheric dynamics and potential habitability of distant worlds. The findings highlight the significance of tailored models in exoplanetary research, aiming to bridge the gap between planetary sciences and climatological studies, ultimately offering a pathway to understanding the climatic regimes that might support life in the universe.