JOVIAN STRATOSPHERE AS A CHEMICAL TRANSPORT SYSTEM: BENCHMARK ANALYTICAL SOLUTIONS
JOVIAN STRATOSPHERE AS A CHEMICAL TRANSPORT SYSTEM: BENCHMARK ANALYTICAL SOLUTIONS
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木星平流层作为化学运输系统：基准分析解决方案
DOI：
10.1088/0004-637x/767/2/172
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
Y. Yung
中科院分区：
文献类型：
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作者：
Xi Zhang;R. Shia;Y. Yung
我们系统地研究了一维和二维（1D 和 2D）化学-平流-扩散系统中可解的分析基准案例。我们以木星的平流层为例，但结果可以应用于其他行星大气和系外行星大气。在一维系统中，我们表明CH4和C2H6主要处于扩散平衡状态，并且C2H2分布可以通过修正贝塞尔函数来近似。在子午面的二维系统中，推导了两种典型环流模式的解析解。简单的示踪剂输运模型表明，短寿命物种（如 C2H2）的分布主要受当地化学源和汇的影响，而长寿命物种（如 C2H6）的分布则受环流模式的显着影响。我们发现赤道到极地的环流可以定性地解释卡西尼号的观测结果，但纯粹的扩散传输过程却不能。对于像近距离太阳系外行星这样缓慢旋转的行星，纬向风的平流与化学之间的相互作用可能会导致最终示踪剂分布和原始源分布之间的相位滞后。二维 Caltech/JPL 化学输运模型的数值模拟结果与各种情况的解析解非常吻合。
We systematically investigated the solvable analytical benchmark cases in both one- and two-dimensional (1D and 2D) chemical–advective–diffusive systems. We use the stratosphere of Jupiter as an example but the results can be applied to other planetary atmospheres and exoplanetary atmospheres. In the 1D system, we show that CH4 and C2H6 are mainly in diffusive equilibrium, and the C2H2 profile can be approximated by modified Bessel functions. In the 2D system in the meridional plane, analytical solutions for two typical circulation patterns are derived. Simple tracer transport modeling demonstrates that the distribution of a short-lived species (such as C2H2) is dominated by the local chemical sources and sinks, while that of a long-lived species (such as C2H6) is significantly influenced by the circulation pattern. We find that an equator-to-pole circulation could qualitatively explain the Cassini observations, but a pure diffusive transport process could not. For slowly rotating planets like the close-in extrasolar planets, the interaction between the advection by the zonal wind and chemistry might cause a phase lag between the final tracer distribution and the original source distribution. The numerical simulation results from the 2D Caltech/JPL chemistry-transport model agree well with the analytical solutions for various cases.