Probing upper thermospheric neutral densities at Mars using electron reflectometry
Probing upper thermospheric neutral densities at Mars using electron reflectometry
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DOI：
10.1029/2005gl024337
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发表时间：
2005-12
影响因子：
5.2
通讯作者：
R. Lillis;Jesse Engel;D. Mitchell;David A. Brain;R. P. Lin;S. Bougher;Mario H. Acuña
中科院分区：
文献类型：
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作者：
R. Lillis;Jesse Engel;D. Mitchell;David A. Brain;R. P. Lin;S. Bougher;Mario H. Acuña
我们提出了一种新的技术推断中性密度在火星高层大气中的磁反射太阳风电子的大气吸收。利用1999年至2005年火星全球探测器（MGS）上的磁强计/电子反射计（MAG/ER）实验的电子损失锥测量结果，我们连续获得了160°至200°E当地时间凌晨2点南半球上热层（160-230 km高度）的密度。我们发现在160 km处的平均密度为0.027 kg/km 3，并观察到1.8-4倍的纬度依赖性，可重复的季节变化，年际差异和50°-55 ° S的冬季密度始终低于0°-30 ° S。的平均密度，整体的季节变化和纬度的依赖性与火星热层全球环流模式（MTGCM）的一般协议。这些测量对于更好地了解火星高层大气的动力学和规划航天器的空气制动机动是重要的。
We present a new technique for inferring neutral densities in the Martian upper atmosphere from atmospheric absorption of magnetically reflected solar wind electrons. Using electron loss cone measurements from the Magnetometer/Electron Reflectometer (MAG/ER) experiment on board Mars Global Surveyor (MGS), we derive upper thermospheric (∼160–230 km altitude) densities in the southern hemisphere from 160° to 200°E at 2am local time, continuously from 1999 to 2005. We find a mean density of 0.027 kg/km3 at 160 km and observe a latitude‐dependent, repeatable seasonal variation of a factor of 1.8–4, with inter‐annual differences and consistently lower winter densities at 50°–55°S, compared with 0°–30°S. The mean densities, overall seasonal variation and latitude dependence are in general agreement with the Mars Thermosphere Global Circulation Model (MTGCM). These measurements are important for improved understanding of the dynamics of Mars' upper atmosphere and for planning spacecraft aerobraking maneuvers.