Jovian Zonal Winds Revealed from Cassini/VIMS Observations
木星带状风的揭示:来自卡西尼/VIMS观测
Shenghan Ma, Yuming Wang, Tao Li, Quanhao Zhang, Jiajia Liu, Ruobing Zheng
AI总结 本文提出一种基于相关性的方法,利用卡西尼飞船近红外数据研究木星不同高度的带状风,揭示了五个主要纬度的风分布及赤道垂直风剪切特征。
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理解木星的带状风对于揭示其大气动力学至关重要。过去几十年中,多种数据源和技术已被用于研究木星的带状风。本文开发了一种基于相关性的方法,利用卡西尼飞船的近红外数据来研究不同高度的带状风。该方法利用木星的自转扫描行星,通过分析特定像素的光变曲线来获取风速。该方法允许从卡西尼/VIMS光谱数据中在多个波段提取风速,尽管数据的空间分辨率低且采样不均匀。通过将此方法应用于2001年1月15日和16日获得的两个VIMS数据立方体,我们揭示了五个主要纬度的带状风,并利用三个不同波段的信息,以及赤道处的风垂直结构,显示出显著的对流层垂直风剪切。我们推导出的垂直风剪切比以前的研究报告要弱,突显了木星大气中多种动态过程的复杂相互作用,反映了其大气循环的复杂性。尽管由于卡西尼/VIMS-IR光谱数据的空间/时间分辨率低和采样不均匀而存在不确定性,但本文建立的新方法最大限度地利用了卡西尼/VIMS数据来理解木星的带状风。进一步的观测对于探索木星大气中的基本机制至关重要。
Understanding Jupiter's zonal winds is crucial to unraveling the dynamics of its atmosphere. Over the last decades, multiple data sources and techniques have been used to study zonal winds in Jupiter. Here, we develop a correlation-based method for the near-infrared data from the Cassini spacecraft to investigate zonal winds at different altitudes. The new method uses Jupiter's rotation to scan the planet as it rotates, allowing retrieval of winds from the analysis of light-curves of specific pixels over the Jovian disc. The method allows the retrieval of winds at multiple wavelengths from the Cassini/VIMS spectral data despite the low spatial resolution and the non-uniform cadence of the data. By applying this method to two VIMS data cubes acquired on 15 January 2001 at 09:42 UT and 16 January 2001 at 03:22 UT, we reveal the zonal winds at five main latitudes using information from three different wavebands, as well as the wind vertical structure at the equator, showing significant vertical wind shear in the troposphere. The vertical wind shear we derived is weaker than as reported in previous studies, highlighting the intricate interactions among multiple dynamical processes in Jupiter's atmosphere and reflecting the complexity of its atmospheric circulation. Despite the uncertainty due to the low spatial/temporal resolution and non-uniform cadence of the Cassini/VIMS-IR spectral data, the new method established in this study maximizes the value of the Cassini/VIMS in understanding Jupiter's zonal winds. Further observations are essential to explore the underlying mechanisms in Jupiter's atmosphere.