AI 中文总结
研究类地行星额外气候反馈对长期气候演变和复杂性的影响，扩展低阶气候模型并增加广义反馈，通过35864次模拟用最大Lyapunov指数表征动力学行为，发现混沌行为分布特点及火山排气量对其的影响。
AI 中文摘要
类地行星的长期宜居性由调节表面温度和大气成分的正负气候反馈平衡所控制。虽然一些反馈，如冰反照率和硅酸盐风化，被认为在许多类地行星上起作用，但额外气候反馈的数量和强度可能因世界而异。一个重要的开放性问题是，额外的气候反馈是否以及如何影响长期气候演变和复杂性。为了研究这个问题，我们扩展了一个低阶气候模型，该模型包括向外长波辐射、冰反照率和碳酸盐 - 硅酸盐风化，并增加了一个额外的广义反馈。在35864次模拟中，我们使用最大Lyapunov指数（LLE）来表征动力学行为。虽然10.4%的探索参数组合表现出正LLE，表明存在混沌，但在稳定的近冰点区域，这一比例上升到25.6%。这表明混沌行为优先集中在强稳定反馈与强不稳定反馈在相同温度区域运行的地方，这与额外的负反馈应增加气候稳定性的预期相反。增加归一化火山排气量会使混沌区域向较低的恒星通量移动，并在高恒星辐射时部分抑制混沌。
英文摘要
The long-term habitability of Earth-like planets is governed by the balance of positive and negative climate feedbacks that regulate surface temperature and atmospheric composition. While some feedbacks, such as ice-albedo and silicate weathering, are thought to operate on many terrestrial planets, the number and strength of additional climate feedbacks may vary substantially from world to world. An important open question is whether and how the introduction of an additional climate feedback influences long-term climate evolution and complexity. To investigate this question, we extended a low-order climate model including outgoing longwave radiation, ice--albedo, and carbonate--silicate weathering, with an additional generalized feedback. Across 35,864 simulations, we characterized dynamical behavior using the largest Lyapunov exponent (LLE). While 10.4% of explored parameter combinations exhibited positive LLEs, indicating chaos, the fraction rose to 25.6% within the stabilizing, near-freezing regime. This suggests that chaotic behavior is preferentially concentrated where a strong stabilizing feedback operates in the same temperature regime as a strong destabilizing feedback, contrary to the expectation that additional negative feedbacks should increase climate stability. Increasing normalized volcanic outgassing shifts the chaotic regime toward lower stellar flux and partially suppresses chaos at high instellation.
Comments17 pages, 8 figures, accepted for publication in the Astrophysical Journal Letters
