Sulfur-water chemistry plays an important role in the middle atmosphere of Venus. Ground based observations have found that simultaneously observed SO2 and H2O at ~64 km vary with time and are temporally anti-correlated. To understand these observations, we explore the sulfur-water chemical system using a one-dimensional chemistry-diffusion model. We find that SO2 and H2O mixing ratios above the clouds are highly dependent on mixing ratios of the two species at the middle cloud top (58 km). The behavior of sulfur-water chemical system can be classified into three regimes but there is no abrupt transition among these regimes. In particular, there is no bifurcation behavior as previously claimed. We also find that the SO2 self-shielding effect causes H2O above the clouds to respond to the middle cloud top in a non-monotonic fashion. Through comparison with observations, we find that mixing ratio variations at the middle cloud top can explain the observed variability of SO2 and H2O. The sulfur-water chemistry in the middle atmosphere is responsible for the H2O-SO2 anti-correlation at 64 km. Eddy transport change alone cannot explain the variations of both species. These results imply that variations of species abundance in the middle atmosphere are significantly influenced by the lower atmospheric processes. Continued ground-based measurements of the co-evolution of SO2 and H2O above the clouds and new spacecraft missions will be crucial for uncover the complicated processes underlying the interaction among the lower atmosphere, the clouds and the middle atmosphere of Venus.
A Comprehensive Sulfur Chemistry Network Including Excited S(1D) and SO(1Δ) for the XODIAC Photochemical Model: Accounting for Missing Sulfur Processes in Venus and Exo-Venus Analogs
National Institute of Science Education and Research（国家科学教育研究中心）；Homi Bhabha National Institute（霍米·巴巴国立研究所）
On the estimation of Sulfuric Acid Vapor concentrations below the Venus cloud deck using the Akatsuki Radio Science Experiment
Space Physics Laboratory, VSSC（空间物理实验室，VSSC）；Research Centre, University of Kerala（喀拉拉大学研究中心）；Graduate School of Frontier Sciences, The University of Tokyo（东京大学前沿科学研究生院）；Faculty of Science, Kyoto Sangyo University（京都产业大学理学部）
A Fast, Semi-analytical Model for the Venusian Binary Cloud System
金星云起源于H $_{2}$ SO $_{4}$和H $_{2}$ O的二元凝聚。这两种成分通过化学和云的形成相互作用。以前的工作采用复杂的微物理方法来理解云。在这里，我们表明，所观察到的金星上的蒸汽和云的分布可以很好地解释了一个半分析模型。我们的模式假设了水蒸气的局部热力学平衡，但不考虑硫酸蒸气，并考虑了云凝结和酸度对蒸气分布的反馈。该模型预测强过饱和的H $_{2}$ SO $_{4}$蒸气60公里以上，与我们最近的云凝结模型。半解析模型比凝聚模型快100倍，比微物理模型快1000倍。这使我们能够快速探索硫酸气云系统的大参数空间。结果表明，高空云质量负荷对低层大气水汽混合比的响应与低层云质量负荷的响应相反。水蒸气的输送对各层云的酸度都有影响，而硫酸蒸气的输送只在低层云中起主导作用。这个云模型足够快，可以与气候模型和化学模型相结合，以了解金星和金星类太阳系外行星的多云大气。
Altered Cosmic Organics as Venus' Ultraviolet Absorbers
California State Polytechnic University, Pomona（加州州立理工大学波莫纳分校）；Blue Marble Space（蓝色大理石空间研究所）；Arizona State University（亚利桑那州立大学）；NASA Goddard Institute for Space Studies（美国宇航局戈达德太空研究所）；Uppsala University（乌普萨拉大学）；University of Wisconsin, Madison（威斯康星大学麦迪逊分校）
The Venus Benchmark: Resolving Degeneracies in Terrestrial Exoplanet Spectra with DAVINCI
University of California, Riverside（加州大学河滨分校）；NASA Goddard Space Flight Center（美国宇航局戈达德太空飞行中心）；Jet Propulsion Laboratory, California Institute of Technology（加州理工学院喷气推进实验室）；Johns Hopkins University Applied Physics Laboratory（约翰斯·霍普金斯大学应用物理实验室）
