概括
开拓者金星的测量显示,夜间有显著的电离层等离子体密度变化. 需要一种能量来源,可能是焦耳加热,来解释观察到的离子温度,这表明太阳风的相互作用.
科学领域:
- 行星科学 行星科学
- 空间物理 空间物理
- 大气科学 大气科学
背景情况:
- 先金星任务提供了金星夜侧电离层的现场测量.
- 以前的研究表明,金星的电离层等离子体密度存在变化.
研究的目的:
- 分析开拓者金星减速潜力分析仪数据,以检测夜边的电离层特征.
- 为了将测量的离子和电子温度与初步的白天和夜晚模型进行比较.
- 调查有助于电离层温度的能量来源.
主要方法:
- 使用了从先金星减速电位分析仪的现场测量.
- 分析了不同高度的等离子体密度和温度变化.
- 将实验数据与初步的离子和电子温度高度配置文件进行比较.
主要成果:
- 观测到夜边电离层等离子体密度的显著空间和时间变化.
- 确定了电离断层是血度急剧下降的区域.
- 测量了250公里以上的夜间离子和电子温度,可比,在离子停止时约为8000K.
- 电子温度在离子断层之外显著增加,进入了被冲击的太阳风.
- 在145公里处最冷的离子温度为140-150K,高于中性温度.
- 需要~4 x 10(-3) erg/cm2/s (朱尔加热) 的离子能量源来匹配模型与测量离子温度.
- 估计太阳风向中性大气中的热量流量为0.05 erg/cm2/s.
结论:
- 焦勒加热是金星夜侧离子层的一个可能重要的能量来源.
- 太阳风向中性大气的热量流量很大.
- 太阳风能消耗在金星大气与离子层相互作用中起着关键作用.
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