Influence of CO2 line profiles on radiative and radiative‐convective equilibrium states of the Venus lower atmosphere
Influence of CO2 line profiles on radiative and radiative‐convective equilibrium states of the Venus lower atmosphere
复制标题
CO2线剖面对金星低层大气辐射和辐射对流平衡状态的影响
DOI：
10.1029/2009je003488
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发表时间：
2010
影响因子：
--
通讯作者：
Y. Matsuda
中科院分区：
文献类型：
--
作者：
M. Takagi;K. Suzuki;H. Sagawa;P. Baron;J. Mendrok;Y. Kasai;Y. Matsuda
[1]本文研究了金星大气中CO2谱线廓线对辐射平衡和辐射对流平衡中垂直温度分布的影响。由Voigt（洛伦兹）的轮廓没有线截止所获得的CO 2不透明度被证明是过度的，因为这种不透明度给出了约860-1020 K的辐射-对流平衡的表面温度。另一方面，由Pollack等人（1993）和Tonkov等人（1996）的极端次洛伦兹分布得到的不透明度被低估了;即使在辐射平衡中，用这种不透明度得到的表面温度仍然保持在600 K。在这种情况下，由于云层的不透明性，对流不会在云层下面发生。它还表明，Eschabori等人。的（1986）和Meadows和Crisp的（1996）剖面，这两个剖面都具有中等吸收系数，它们给出的温度分布接近于辐射-对流平衡时的观测值。在这些情况下，对流层从地面延伸到30-50公里的高度。然后，由干绝热直减率和云底附近的温度确定云层下面的温度分布。在这种情况下，辐射对流平衡的地面温度强烈地受云底附近温度的影响。建立一个真实的H2SO 4云辐射传输模型必须考虑H2SO 4云的详细结构。
[1] Influence of CO 2 line profiles on vertical temperature distributions in the radiative and radiative-convective equilibria is examined in the Venus atmosphere. The CO 2 opacity obtained by the Voigt (Lorentz) profile without the line cutoff is shown to be excessive since this opacity gives surface temperatures of about 860-1020 K in the radiative-convective equilibrium. On the other hand, the opacity obtained by the extremely sub-Lorentzian profiles of Pollack et al. (1993) and Tonkov et al. (1996) are underestimated; the surface temperature obtained with this opacity remains 600 K even in the radiative equilibrium. In this case, convection does not take place below the cloud layer because of the cloud opacity. It is also shown that Fukabori et al.'s (1986) and Meadows and Crisp's (1996) profiles, both of which have intermediate absorption coefficients, give temperature distributions close to the observed one in the radiative-convective equilibrium. In these cases, the convection layer extends from the surface to 30-50 km altitudes. Then, the temperature distribution below the cloud layer is determined by a dry adiabatic lapse rate and the temperature near the cloud bottom. The surface temperature in the radiative-convective equilibrium is strongly affected by the temperature near the cloud bottom in this situation. The detailed structure of the H 2 SO 4 cloud must be taken into account to construct a realistic radiative transfer model.