Authors: Scott M. Bailey, Erica M. Rodgers, Justin Yonker; Daniel N. Baker
Affiliation: University of Alaska; LASP, University of Colorado
The production of nitric oxide is a key response of the upper atmosphere to
solar energy deposition. NO plays a strong role in the thermospheric energy
balance as it emits efficiently in the infrared, it is the terminal ion in the
lower ionosphere, and if transported to lower altitudes will catalytically destroy
ozone. NO is primarily produced through the reaction of excited atomic nitrogen
with molecular oxygen. One of the primary loss mechanisms of NO is photodissociation
by solar ultraviolet irradiance. In order to produce the excited atomic nitrogen
atom, the strong N2 molecular bond must be broken. At low latitudes, solar soft
X-ray irradiance is the energy source that leads to NO. At high latitudes, auroral
electrons and the energetic secondary electrons provide the source of energy
that leads to the large amounts of NO observed there. Coupling between latitude
regions may occur as high latitude NO is transported by winds to lower latitude.
In this talk we describe observations of NO from the Student Nitric Oxide Explorer
(SNOE). SNOE obtained global observations of lower thermospheric NO from February
1998 through December 2003. We will present case studies of the observed response
to large auroral storms. In particular, the effects of the large storms of April
2002 and November 2003 will be presented. The SNOE observations show that auroral
energy deposition produces a significant global effect on the upper atmosphere.