Titan's stratospheric zonal wind, temperature, and ethane abundance a year prior to Huygens insertion
Titan's stratospheric zonal wind, temperature, and ethane abundance a year prior to Huygens insertion
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惠更斯插入前一年土卫六的平流层纬向风、温度和乙烷丰度
DOI：
10.1029/2005gl023897
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发表时间：
2005
影响因子：
5.2
通讯作者：
F. Schmülling
中科院分区：
文献类型：
--
作者：
T. Kostiuk;T. Livengood;T. Hewagama;G. Sonnabend;K. Fast;Koji Murakawa;Alan T. Tokunaga;J. Annen;David Buhl;F. Schmülling
土星的卫星土卫六，平流层的风速可能高达每秒210米，与土卫六16天的自转相比，它在201个地球日内环绕土卫六。解释这种超级旋转风的理论模型并没有很好地受到土卫六或类似的慢旋转体金星的观测的约束。我们报告的测量结果在2003年12月土卫六的赤道地区附近的纬向风，包括卡西尼惠更斯探测器进入纬度。从12 μm附近的多普勒频移C2 H6气体排放中发现了220 km高度附近190 ± 90 m/s的超旋转纬向风，证实了即使在赤道附近也有高风速。还反演了平流层温度约束和乙烷丰度（8 ± 3 ppm）。结果与早期的测量和最近的卡西尼CIRS结果并不矛盾，但表明土卫六半球之间可能存在差异。东、西C2 H6谱线形状的差异可以由C2 H6丰度或温度的不同垂直分布或未识别的动力学效应来解释。
Saturn's satellite, Titan, may have stratospheric winds up to ∼210 m/s, circling Titan in ∼1 terrestrial day compared to its 16‐day rotation. Theoretical models explaining such super‐rotating winds are not well constrained by observations of Titan or a similar slow rotator, Venus. We report measurements taken in December 2003 of zonal wind near Titan's equatorial region, including the Cassini Huygens probe entry latitude. Super‐rotating prograde zonal winds of 190 ± 90 m/s near 220 km altitude are found from Doppler‐shifted C2H6 gas emission near 12 μm, confirming high wind velocity even near the equator. Stratospheric temperature constraints and ethane abundance (8 ± 3 ppm) also are retrieved. Results are not inconsistent with earlier measurements and with recent Cassini CIRS results, but indicate possible variations between Titan's hemispheres. Differences in east and west C2H6 spectral line shapes can be accounted for by different vertical distributions of either C2H6 abundance or temperature or by unidentified dynamical effects.