Investigation of the radiative energy balance of Venus based on improved models of the middle and lower atmosphere

该研究计划旨在调查金星在中低层大气（90-0公里）的辐射能量平衡。为此目的，将应用新的检索技术，以促进对大气温度场、云特征和微量气体分布的改进模型的推导。这项提议的工作是基于对欧洲航天局金星快车任务上的可见光和红外热成像光谱仪（VIRTIS）在近红外光谱区域记录的辐射测量数据的分析。作为热红外区域数据库的补充，还打算使用俄罗斯金星-15实验（1983）上的傅立叶光谱仪测量。申请人作为共同研究者参与了这两个实验，并拥有不受限制的数据访问权。改进大气模型的推导方法将同时利用行星夜侧的各种透明窗口（多窗口使用），这些窗口可产生0-90公里高度范围内的大气特征信息。为此目的将采用新的和正在筹备工作中发展和验证的辐射转移模式，这些模式将考虑到稠密低层大气的极端环境条件，并与传统模式明显不同。在此基础上并已得到一定程度成功验证的新检索方法将允许同时使用大量光谱（多光谱使用）。他们能够分离大气参数温度、云和微量气体分布对测量光谱的影响，并对参数本身进行量化。除此之外，这些技术将首次有助于确定波长相关的大气连续体吸收，目前可用的模型没有充分考虑其对大气透明窗口的强烈影响。由此可大大提高反演大气参数的精度。这个金星研究项目结合了利用迄今为止最好的遥感数据档案和适应新的复杂分析方法来检索大气状态参数。导出的多维参数图随后将用于计算中低层大气中随位置和时间变化的净辐射通量，并研究可能的参数变化的影响。净通量垂直辐散导致的随海拔变化的升温和降温速率将为探索动力过程和全球环流机制提供新的数据基础。

The research proposal aims to investigate the radiative energy balance of Venus in the middle and lower atmosphere (90-0 km). Novel retrieval techniques will be applied for this purpose that facilitate a derivation of improved models of atmospheric temperature fields, cloud features, and trace gas distributions.The proposed work is based on analyses of radiation measurement data that were recorded by the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) aboard ESA’s Venus-Express mission in the near-infrared spectral region. As supplement to the database for the thermal infrared region, it is also intended to use Fourier spectrometer measurements aboard the Russian Venera-15 experiment (1983). The applicant is/was involved in the two experiments as Co-Investigator and has unrestricted data access. The methods for derivation of improved atmospheric models will simultaneously utilize various transparency windows on the nightside of the planet (multi-window use) that yield information on atmospheric features in the altitude range 0-90 km. New and in preparatory work developed and verified radiative transfer models will be employed for this purpose that consider the extreme environmental conditions of the dense lower atmosphere and that clearly differ from conventional models. Novel retrieval methods, which are based hereupon and which have been already successfully verified to some extent, will allow for the simultaneous use of a large number of spectra (multi-spectrum use). They are able to separate influences of the atmospheric parameters temperature, cloud, and trace gas distribution on measured spectra, and to quantify the parameters themselves. Beyond that, these techniques shall facilitate for the first time the determination of wavelength-dependent atmospheric continuum absorption, the strong influence of which on the atmospheric transparency windows was not sufficiently considered by currently available models. The accuracy of retrieved atmospheric parameters can be substantially enhanced thereby. This Venus research project combines the utilization of the best ever available remote sensing data archive with the adaptation of novel sophisticated analysis methods to retrieve atmospheric state parameters. Derived multi-dimensional parameter maps will be subsequently used to calculate location and time-dependent net radiation fluxes in the middle and lower atmosphere and to study impacts of possible parameter variations. Altitude-dependent heating and cooling rates resulting from the vertical divergence of net fluxes will provide a new data base for the exploration of dynamical processes and global circulation mechanisms.