Tracing solar energy through the upper atmosphere: SNOE and TIMED observations of nitric oxide
Abstract
As solar particle and photon energy is deposited into the upper atmosphere, the immediate ionization, dissociation, and excitation of atoms and molecules leads to important modifications of the composition and temperature there. A key product of these energetic processes is nitric oxide. Though always a minor species, NO plays a strong role in the thermospheric energy balance because unlike the major species O, O2, and N2, it emits efficiently in the infrared. Radiance from NO is then a key process by which the atmosphere cools in response to solar energy deposition. The presence of NO has other important impacts on the chemistry and ion composition in the atmosphere. Recent observations of NO have revealed dramatic global increases of NO in response to solar energetic particle precipitation and soft X-ray irradiance. The morphology of these responses has been particularly interesting in that winter hemisphere NO appears to be primarily controlled by high latitude energetic particle precipitation, while energetic particles appear to have little or no impact in the summer hemisphere. Thus the nature of the coupling between the Sun and Earth's upper atmosphere is highly variable in time and space. This complex coupling is well demonstrated by observations of the response to large solar eruptive events such as occurred in April of 2002 and October of 2003. In this talk we will focus on these and other large events to show the morphology of NO in response to solar storms and to elucidate the processes governing that response. Observations of NO abundance from the Student Nitric Oxide Explorer (SNOE) and of NO radiance from the Thermosphere Ionosphere Mesosphere Energetics and Dynamics missions will be utilized.
- Publication:
-
AGU Spring Meeting Abstracts
- Pub Date:
- May 2005
- Bibcode:
- 2005AGUSMSA12A..05B
- Keywords:
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- 0335 Ion chemistry of the atmosphere (2419;
- 2427);
- 0340 Middle atmosphere: composition and chemistry;
- 0355 Thermosphere: composition and chemistry;
- 0358 Thermosphere: energy deposition