Dunes on Titan observed by Cassini Radar
Dunes on Titan observed by Cassini Radar
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DOI：
10.1016/j.icarus.2007.10.015
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发表时间：
2008-04
期刊：
影响因子：
3.2
通讯作者：
J. Radebaugh;R. Lorenz;J. Lunine;S. Wall;G. Boubin;E. Reffet;R. Kirk;Rosaly M. C. Lopes;E. Stofan;L. Soderblom;M. Allison;M. Janssen;P. Paillou;P. Callahan;C. Spencer
中科院分区：
文献类型：
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作者：
J. Radebaugh;R. Lorenz;J. Lunine;S. Wall;G. Boubin;E. Reffet;R. Kirk;Rosaly M. C. Lopes;E. Stofan;L. Soderblom;M. Allison;M. Janssen;P. Paillou;P. Callahan;C. Spencer
泰坦雷达制图仪最近在泰坦表面发现了数千个纵向沙丘。这些主要在赤道±30°以内的光学、近红外和雷达暗区发现，表明有机物的比例很高，覆盖了泰坦表面的5%以上。它们的纵向沙丘形态、与地形的相互作用以及与其他风成形态的相关性表明，它们具有一个单一的主导风向，该风向与沙丘轴线一致，加上较小的离轴风或季节性交替风。沙丘方向的全球汇编显示，平均风向主要是向东，区域和局部变化，风被转向周围地形高的功能，如山块或广泛的地形。全球风可能会将沉积物从高纬度地区带到赤道地区，那里的条件相对干燥，颗粒被重新形成沙丘，时间跨度可能为数千到数万年。在土卫六上，充足的沉积物供应，充足的风，以及没有沉积物搬运和流体捕获是沙丘存在的主要因素。
Thousands of longitudinal dunes have recently been discovered by the Titan Radar Mapper on the surface of Titan. These are found mainly within ±30° of the equator in optically-, near-infrared-, and radar-dark regions, indicating a strong proportion of organics, and cover well over 5% of Titan's surface. Their longitudinal duneform, interactions with topography, and correlation with other aeolian forms indicate a single, dominant wind direction aligned with the dune axis plus lesser, off-axis or seasonally alternating winds. Global compilations of dune orientations reveal the mean wind direction is dominantly eastwards, with regional and local variations where winds are diverted around topographically high features, such as mountain blocks or broad landforms. Global winds may carry sediments from high latitude regions to equatorial regions, where relatively drier conditions prevail, and the particles are reworked into dunes, perhaps on timescales of thousands to tens of thousands of years. On Titan, adequate sediment supply, sufficient wind, and the absence of sediment carriage and trapping by fluids are the dominant factors in the presence of dunes.