标题： 金星云层气溶胶液相中UV-蓝吸收模型与高浓度的有效有机吸收剂一致 显示英文标题

标题： A Model of UV-Blue Absorbance in Bulk Liquid of Venusian Cloud Aerosols Is Consistent with Efficient Organic Absorbers at High Concentrations

摘要： 在可见光波长下，金星看起来宁静且呈淡黄色，但自20世纪20年代以来，观察者注意到紫外线中的高对比度特征。这些特征追踪了大约4天的上层云层超速旋转，并随时间和空间广泛变化。位于至少280到500纳米之间的紫外吸收剂的身份仍然未知，因为没有一个提出的候选者完全符合所有观测数据。 从金星的远程观测，并考虑到亚微米液滴的光散射，我们模拟了形成金星云层的总体积液体在365至455纳米范围内的每厘米吸光度。假设模式1和模式2颗粒在海拔65公里处顶层云以下的6公里层中均匀分布，我们通过峰值在A375纳米处的吸光度为2942每厘米来限制总体积吸光度。这种极高的吸光度表明存在高效吸收剂，最有可能是共轭有机物，在相对较高的浓度下——例如，卟啉类色素约为25克/升。无机吸收剂，其摩尔吸收系数通常在1,000到10,000每M每厘米的范围内，要么需要构成气溶胶的大部，要么仅仅是不够强的光吸收剂，即使以纯形式存在。 我们强调，所有候选吸收剂都必须使用（i）已知的摩尔吸收系数，（ii）现实的大气分布，以及（iii）适当的颗粒尺寸分布来评估金星的反射曲线。即将进行的火箭实验室任务将测试金星云层中有机物的假设。 显示英文摘要

摘要： At visible wavelengths, Venus appears serene and pale-yellow, but since the 1920s, observers have noted high-contrast features in the ultraviolet. These features track the about 4-day superrotation of the upper cloud deck and vary widely over time and space. The identity of the UV absorber(s)-active between at least 280 and 500 nm-remains unknown, as no proposed candidate fully matches all observational data. From remote observations of Venus, and accounting for light scattering by sub-micrometer droplets, we modeled the 365-455 nm absorbance per cm of the bulk liquids forming Venus's clouds. Assuming a uniform distribution in mode 1 and 2 particles across a 6 km layer below the cloud top at 65 km, we constrain the bulk absorbance with a peak at A375 nm being 2942 per cm. This extremely high absorbance implies the presence of a highly efficient absorber, most likely conjugated organics, at relatively high concentration-e.g. about 25 g/L for porphyrin type pigments. Inorganic absorbers, with molar absorption coefficients typically in the range of 1,000-10,000 per M per cm, would either need to comprise a large portion of the aerosols or are simply not light absorbent enough, even if present in pure form. We emphasize that all candidate absorbers must be evaluated against Venus's reflectance curve using (i) known molar absorption coefficients, (ii) realistic atmospheric distributions, and (iii) appropriate particle size distributions. The upcoming Rocket Lab mission will test the hypothesis of organics in Venus's clouds.