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雲の非対称性は,金星の初期の海洋を防ぐが,地球ではそうではない
Martin Turbet1, Emeline Bolmont2, Guillaume Chaverot2
1Observatoire astronomique de l'Université de Genève, Versoix, Switzerland. martin.turbet@unige.ch.
Nature
|October 14, 2021
まとめ
初期の金星にはおそらく 表面上の海はありませんでした 水の雲が温暖化効果をもたらし 凝縮を防ぎました 地球
科学分野:
- 惑星科学
- 気候モデリング
- 天体生物学
背景:
- 地球は40億年近く前から海があり 火星は過去に水面があった証拠を示しました
- 金星は現在完全に乾燥しており 初期の歴史は地球表面の再現によって隠されています
- 惑星の水凝縮に関する以前の研究は 限られた一次元的な気候モデルを使用していました
研究 の 目的:
- 初期の金星と地球での水凝縮の条件を調査するために
- 地球の気候の安定化における 大気循環と雲の役割を理解する
- 金星の表面に 海洋があったか調べるため
主な方法:
- 初期の金星と地球の3次元気候モデルシミュレーションを利用した.
- 水雲の影響を分析した. 特にその夜間形成と温暖化効果.
- 異なるインソレーションレベルの気候条件をシミュレートします.
主要な成果:
- 初期の金星の水雲は 温暖化効果を生み出し 表面水の凝縮を阻害しました
- 温和なインソレーションレベル (0.95倍の地球の太陽定数) でさえ,金星は地表水を維持することができなかった.
- 地球の海は,弱い若い太陽のために,かなり低い太陽照射条件下で形成された可能性が高い.
結論:
- 水が表面に凝縮できないため 海洋は形成されませんでした
- 地球の海洋形成は 弱くなった初期の太陽によって促進されました
- すべての水が蒸発した"蒸気地球"状態は,現在の地球にとって潜在的な代替安定状態です.
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