A simple‐physics global circulation model for Venus: Sensitivity assessments of atmospheric superrotation
A simple‐physics global circulation model for Venus: Sensitivity assessments of atmospheric superrotation
复制标题
金星的简单物理全球环流模型：大气超自转的敏感性评估
DOI：
10.1029/2006gl028567
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发表时间：
2007
影响因子：
5.2
通讯作者：
A. Grossman
中科院分区：
文献类型：
--
作者：
J. Hollingsworth;R. Young;G. Schubert;C. Covey;A. Grossman
一个3D全球环流模型被改装到金星的大气中，以探索该行星大气超级自转的本质。该模式采用了完整的气象原始方程和非绝热及其他非保守强迫的简化形式。因此，执行非常长的模拟是经济的。为了评估环流平衡和大气超旋转的发生，气候模式在4°×5°经纬度水平分辨率和56个垂直层(记为L56)上运行了10,000-20,000天的积分。除了模式配置(如低垂直域与高垂直域和大气层数)外，还考察了这些模拟对强加的类金星非绝热加热率、动量耗散率和各种其他关键参数(例如近地表动量阻力)的敏感性。我们在几个数值实验中发现了赤道超自转，但超自转的大小往往比观测到的要小。此外，平均纬向翻转(即Hadley环流)的经向结构可由许多围绕赤道对称且其深度尺度似乎对模式大气中施加的垂直层数敏感的单体组成。我们发现，当在最低的几个尺度高度施加现实的非绝热加热时，只有极弱的大气超自转结果。
A 3D global circulation model is adapted to the atmosphere of Venus to explore the nature of the planet's atmospheric superrotation. The model employs the full meteorological primitive equations and simplified forms for diabatic and other nonconservative forcings. It is therefore economical for performing very long simulations. To assess circulation equilibration and the occurrence of atmospheric superrotation, the climate model is run for 10,000–20,000 day integrations at 4° × 5° latitude‐longitude horizontal resolution, and 56 vertical levels (denoted L56). The sensitivity of these simulations to imposed Venus‐like diabatic heating rates, momentum dissipation rates, and various other key parameters (e.g., near‐surface momentum drag), in addition to model configuration (e.g., low versus high vertical domain and number of atmospheric levels), is examined. We find equatorial superrotation in several of our numerical experiments, but the magnitude of superrotation is often less than observed. Further, the meridional structure of the mean zonal overturning (i.e., Hadley circulation) can consist of numerous cells which are symmetric about the equator and whose depth scale appears sensitive to the number of vertical layers imposed in the model atmosphere. We find that when realistic diabatic heating is imposed in the lowest several scales heights, only extremely weak atmospheric superrotation results.