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

用大气环流模式研究了陆地行星（没有固定海洋的湿行星）和水行星（完全被海洋覆盖的行星）的完全冻结状态（“雪球”状态）的发生条件，并特别提到了冻结性。结果：1.陆地行星比水行星对完全冻结的抵抗力更强。2.无论是陆地行星还是水行星，在倾斜状态下都比在直立状态下表现出更强的对完全冻结的抵抗力。然而，在正直的政权中，对道德的依赖并不明确。3.在倾斜状态的陆地行星上，低纬度地区比中纬度地区更容易结冰。因此，有一个很好的机会，只有低纬度冻结（冻结低纬度没有冻结整个行星）的陆地行星。4.在一个高湿度的水行星上，低纬度的冻结发生在比陆地行星低的太阳常数下， ...更多信息 高纯度。在水行星上，仅在低纬度产生冻结的太阳常数范围比陆地行星窄得多。因此，在一个水行星上，只有低纬度的冻结是不可能的。对古火星的影响：1。古火星低纬度地区要保持湿润地面，必须处于斜行区，或有海洋存在。然而，在这种情况下，低纬度地区相对容易被永久性积雪覆盖。因此，在低纬度地区保持不冻湿表面比在目前的温度条件下保持火星不完全冻结状态更加困难。2.如果在火星水循环活跃、平均气温持续下降的同时，冰的温度发生了显著变化，那么一定有一段时期，只有低纬度地区被永久性积雪覆盖。我们能否从地质记录中找到这样的证据，这是一个有趣的问题。对行星宜居性的含义：1。一个富含水的水行星可能不是最适合生命的地方，而一个有一些水的陆地行星可能比一个水行星更好，因为一个水行星很容易福尔斯完全冻结的状态。2.高密度行星和低密度行星哪个更好是一个难题。高倾角的行星可以抵抗完全冻结，但会经历严重的季节变化。最平静的气候是在45度水行星上。少

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。

Abe, Y., and A. Abe-Ouchi , edited by H. Mizutani, and M. Kato: "The freezing condition of a land planet : effect of obliquity, in Proceedings of the 35th ISAS Lunar and Planetary Symposium"Institute of Space and Aeronautical Science. 21-24 (2002)

Abe, Y. 和 A. Abe-Ouchi，由 H. Mizutani 和 M. Kato 编辑：“陆地行星的冰冻条件：倾角效应，第 35 届 ISAS 月球和行星研讨会论文集”空间研究所