• ISSN 2097-1893
  • CN 10-1855/P

地球、火星、泰坦和金星极地涡旋的多尺度比较

A multi-scale comparison of polar vortices on Earth, Mars, Titan, and Venus

  • 摘要: 尽管已有的研究分析了地球、金星、火星和土卫六极地涡旋的独特结构特征,但由于观测数据的分辨率和覆盖范围有限,对金星和土卫六极地涡旋的了解主要基于小规模的案例研究. 对太阳系主要陆地行星和土卫六的极涡特征进行详细比较更具挑战性. 为了更细致地比较太阳系主要陆地行星与土卫六的极涡特征,本文基于先进的VCD2.3和TitanWRF 模型,实现了对金星和土卫六在现有条件下的极涡的最优估算. 同时,结合ERA5和EMARS数据库,首次对太阳系内有大气层的陆地行星和最像地球的土卫六卫星的极地涡旋特征进行了详细的时空比较. 本文研究结果有:(1)火星1 mbar水平以上的环流特征与土卫六低层 1000 mbar水平的环流特征非常相似,具有相同高度的季节性变化;(2)与火星和地球极区冬季稳定地保持主导方向的涡旋结构不同,土卫六和金星的涡旋强度峰值出现时间随着高度的增加而逐渐前移;(3)当金星发生涡旋不稳定性漂移时,1 mbar高度的极地涡旋会破裂成带状结构,这种现象与地球上弱平流层极地涡旋事件时的PV结构扭曲变形非常相似.

     

    Abstract: Although previous studies have analyzed the unique structural characteristics of the polar vortices on Earth, Venus, Mars, and Titan, the understanding of the polar vortices on Venus and Titan is primarily based on small-scale case studies due to the limited resolution and coverage of observational data. Conducting a detailed comparison of the polar vortex characteristics between the major terrestrial planets and Titan in the solar system is more challenging. In order to more finely compare the polar vortex characteristics of the main terrestrial planets in the solar system with Titan, we have achieved the optimal estimation of the polar vortices of Venus and Titan under existing conditions based on the advanced VCD2.3 and TitanWRF model. At the same time, combining ERA5 and EMARS databases, a detailed spatiotemporal comparison of polar vortex characteristics between terrestrial planets with atmospheres in the solar system and the most Earth-like Titan satellite was conducted for the first time. Here, we demonstrate that: (1) The circulation characteristics of Mars above the 1 mbar level are very similar to those at 1000 mbar in the lower layers of Titan, with seasonal variations of the same height. (2) In contrast to the vortex structure that is stably maintained in the lead direction in the polar regions of Mars and Earth during the winter, the time of occurrence of the peak vortex intensity at Titan and Venus is gradually shifted forward with increasing altitude. (3) When Venus undergoes vortex instability drift, the polar vortex at an altitude of 1 mbar breaks up into banded structures, a phenomenon that closely resembles the twisting deformation of PV structures during weak stratospheric polar vortex events on Earth.

     

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