Infrared Auroral Emissions Driven by Resonant Electron Impact Excitation of NO Molecules

Infrared Auroral Emissions Driven by Resonant Electron Impact Excitation of NO Molecules

Although only a minor constituent of the earth's upper atmosphere, nitric oxide (NO) plays a major role in infrared auroral emissions due to radiation from vibrationally excited (NO*) states. The main process leading to the production of these excited molecules was thought to be chemiluminescence, whereby excited nitrogen atoms interact with oxygen molecules to form vibrationally excited nitric oxide (NO*) and atomic oxygen. Here we show evidence that a different production mechanism for NO*, due to low energy electron impact excitation of NO molecules, is responsible for more than 30% of the NO auroral emission near 5 μm.

尽管一氧化氮（NO）只是地球高层大气中的一种微量成分，但由于来自振动激发态（NO*）的辐射，它在红外极光发射中起着重要作用。人们曾认为导致这些激发分子产生的主要过程是化学发光，即激发态的氮原子与氧分子相互作用形成振动激发的一氧化氮（NO*）和氧原子。在此我们展示证据表明，由于NO分子受到低能电子撞击激发而产生NO*的一种不同的生成机制，对5μm附近30%以上的NO极光发射负有责任。