Why logarithmic? A note on the dependence of radiative forcing on gas concentration
Why logarithmic? A note on the dependence of radiative forcing on gas concentration
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DOI：
10.1002/2014jd022466
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发表时间：
2014-12
期刊：
影响因子：
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通讯作者：
Yi Huang;M. Bani Shahabadi
中科院分区：
文献类型：
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作者：
Yi Huang;M. Bani Shahabadi
逐线辐射传输计算表明，辐射强迫对气体浓度的对数依赖性不仅适用于宽带辐射通量，如众所周知的CO2强迫情况，而且适用于由于CO2和其他气体（如H2O）引起的光谱辐射率变化。对数关系适用于单色辐射，需要一个超越传统思想的解释，基于气体吸收线的光谱特征。我们表明，这种现象可以解释的发射层位移模型，它描述了正常大气条件下，如温度随高度线性变化和气体浓度随高度呈指数衰减的气体扰动的辐射响应。
Line‐by‐line radiative transfer computations show that the logarithmic dependence of radiative forcing on gas concentration not only applies to broadband irradiation fluxes such as in the well‐known case of the CO2 forcing, but also applies to the spectral radiance change due to both CO2 and other gases, such as H2O. The logarithmic relationship holds for monochromatic radiance requires an explanation beyond the conventional ideas based on the spectroscopic features of the gas absorption lines. We show that the phenomenon can be explained by an Emission Layer Displacement Model, which describes the radiance response to gas perturbation under normal atmospheric conditions such as temperature linearly varying with height and gas concentration exponentially decaying with height.