HR: 13:55h
AN: SA23B-02 INVITED     [Abstracts]
TI: Observations of Lower Thermospheric Nitric Oxide from the Student Nitric Oxide Explorer
AU: * Bailey, S M
EM: scott.bailey@gi.alaska.edu
AF: University of Alaska, Geophysical Institute 903 Koyukuk Dr., Fairbanks, AK 99775-7320 United States
AB: 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 observed fluorescently scattered sunlight by NO at 215 and 237 nm to obtain global concentrations of NO in the lower thermosphere daily 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.
DE: 0310 Airglow and aurora
DE: 0340 Middle atmosphere--composition and chemistry
DE: 0342 Middle atmosphere--energy deposition
DE: 0355 Thermosphere--composition and chemistry
DE: 0358 Thermosphere--energy deposition
SC: SPA-Aeronomy [SA]
MN: 2004 AGU Fall Meeting