Effect of orbital parameters on the habitability on planets

轨道参数对行星宜居性的影响

• 批准号: 13640435
• 负责人: ABE Yutaka
• 金额: $ 2.11万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13640435/
• 关键词: Freezing; Snowball Earth; Spin Obliquity; Aqua-planet; Land-planet; Solar flux; Ice-Albedo-Feedback; スノーボール・アイス

The condition for the occurrence of a completely frozen state (a "snow-ball" state) is investigated with a general circulation model for both a land planet case (a wet planet without fixed ocean) and an aqua planet (a planet entirely covered by an ocean) with a particular reference to the obliquity. Results : 1. A land planet shows stronger resistance to the com-plete freezing than an aqua planet. 2. Both land and aqua planets in an oblique regime show stronger resis-tance to the complete freezing than those in an upright regime. However, the dependence on the obliquity is not clear within the upright regime. 3. On a land planet in an oblique regime, low latitude area is more suscep-tible to freezing than the mid latitude area. Thus, there is a good chance of low-latitude-only freezing (freezing of low latitude without freezing the entire planet) of a land planet. 4. On an aqua planet with high obliquity, low latitude freezing occurs at lower solar constant than on a land planet with h … More igh obliquity. The range of the solar constant that yields low-latitude-only freezing is much narrower on an aqua planet than that on a land planet. Thus, low-latitude-only freezing is unlikely on an aqua planet. Implications for the paleo-Mars : 1. In order to keep a wet ground at the low latitude area of paleo-Mars, the planet must be in the oblique regime, or with oceans. Under such conditions, however, the low latitude is relatively easily covered by permanent snow. Thus, it is more difficult to keep unfrozen wet surface on low latitude than to keep Mars from the completely frozen state under the condition of the present obliquity. 2. If the obliquity changed significantly while Martian water cycle was active and the average temperature was de-creasing steadily, there must have been a period while only the low latitude area is covered by permanent snow. It is an interesting question whether we can find such evidence from geological records. Implication for the Habitability on a Planet : 1. A water rich aqua planet may not be the best place for life, and a land planet with some water may be better than an aqua planet, because an aqua planet easily falls in a completely frozen state. 2. It is a difficult question whether high obliquity or low obliquity planet is prefer-able. A high obliquity planet is resistive to the complete freezing, but experiences severe seasonal change. The calmest climate is found on 45° obliquity aqua planet. Less

研究了发生完全冷冻状态（“雪球”状态）的条件，该状态均通过一般循环模型（无固定海洋的湿行星）和一个特定倾向的陆上行星（完全被海洋覆盖的湿行星（完全被海洋覆盖的行星）（一个完全被海洋覆盖）进行了研究。结果：1。一个地球行星比Aqua星球表现出对冰冻冰冻的阻力。 2。在倾斜政权中，陆地和水上行星都比在直立政权的方向上表现出更强的对完全冷冻的重点。但是，对倾斜的依赖在直立方面尚不清楚。 3。在倾斜状态下的陆地行星上，低纬度区域比中纬度区域更容易冰冻。那就很有可能在陆地星球上只有低纬度的冰冻冻结（在不冻结整个星球的情况下冻结冰冻而冻结）。 4。在具有高倾斜的水上行星上，低纬度冷冻在太阳常数下发生，而不是在h的地球上，h…更多的倾斜度。在水上行星上，产生仅纬度的冰冻的太阳常数的范围要比在陆地星球上窄得多。在水上行星上，仅低纬度的冷冻不可能。对古帝国的影响：1。为了在古帝国的低纬度区域保持潮湿的地面，地球必须处于倾斜状态或海洋。但是，在这种情况下，低纬度相对容易被永久的积雪覆盖。这是要在低纬度上保持未湿润的表面比在当前倾斜状态下完全冷冻的状态更难。 2。如果倾斜在火星水周期活跃时发生了很大的变化，并且平均温度悄悄地降低，则一定有一段时间，而只有低纬度区域被永久降雪覆盖。这是一个有趣的问题，我们是否可以从地质记录中找到此类证据。对行星上的可居住性的含义：1。富含水的水上星球可能不是生命的最佳场所，而一定水的陆地行星可能比水上星球更好，因为一个水上行星很容易落在一个完全冷冻的状态下。 2。这是一个困难的问题，无论是高倾斜还是低倾斜行星。一个高倾斜的星球对完全冻结具有抵抗力，但经历了严重的季节性变化。最平静的气候是在45°倾斜的水上行星上发现的。较少的

项目成果

Kimura, H., Y.Abe, A.Abe-Ouchi: "Role of ocean on planetary climate : an implication for ancient-mars"Lunar and Planetary Science (CD-ROM). XXXIII. 1731 (2002)

Kimura, H.、Y.Abe、A.Abe-Ouchi：“海洋对行星气候的作用：对古代火星的影响”月球与行星科学（CD-ROM）。

Abe, Y., A.Abe-Ouchi: "The effect of obliquity and surface condition on the freezing condition of a planet : implications for paleo-mars climate and habitable condition"Lunar and Planetary Science. XXXIV(CD-ROM). 1617 (2003)

Abe，Y.，A.Abe-Ouchi：“倾斜度和表面条件对行星冻结条件的影响：对古火星气候和宜居条件的影响”月球与行星科学。

Yutaka Abe, Ayako Abe-Ouchi: "The freezing condition of a land planet : effect of obliquity"Proceedings of the ISAS Lunar and Planetary Symposium. 35. 21-24 (2002)

Yutaka Abe、Ayako Abe-Ouchi：“陆地行星的冻结条件：倾角的影响”ISAS 月球和行星研讨会论文集。

Kimura, H., Y.Abe, A.Abe-Ouchi: "Role of ocean on planetary climate : an implication for ancient-mars"Lunar and Planetary Science. XXXIII(CD-ROM). 1731 (2002)

Kimura, H.、Y.Abe、A.Abe-Ouchi：“海洋对行星气候的作用：对古代火星的影响”月球与行星科学。

Kimura, H., Y. Abe, and A. Abe-Ouchi: "Role of ocean on planetary climate : an implication for ancient-mars, in Lunar and Planetary Science XXXIII"Lunar and Planetary Institute (CD-ROM). Abstract #1731 (2002)

Kimura, H.、Y. Abe 和 A. Abe-Ouchi：“海洋对行星气候的作用：对古代火星的影响，月球与行星科学 XXXIII”月球与行星研究所 (CD-ROM)。