HR: 1330h
AN: SA43A-03    [Abstracts]
TI: Rotational and Spin-Orbit Distributions of NO Observed by MIPAS/ENVISAT Under Auroral and Quiescent Conditions
AU: * Gardner, J L
EM: jennifer.gardner@hanscom.af.mil
AF: Stewart Radiance Laboratory, 139 The Great Road, Bedford, MA 01730 United States
AU: López-Puertas, M
EM: puertas@iaa.es
AF: Instituto de Astrofísica de Andalucía (CSIC), Apartado Postal 3004, Granada, 18080 Spain
AU: Funke, B
EM: bernd@iaa.es
AF: Instituto de Astrofísica de Andalucía (CSIC), Apartado Postal 3004, Granada, 18080 Spain
AU: Miller, S M
EM: steven.miller@hanscom.af.mil
AF: Air Force Research Laboratory, Space Vehicles Directorate 29 Randolph Road, Hanscom AFB, MA 01731 United States
AU: Lipson, S J
EM: steven.lipson@hanscom.af.mil
AF: Air Force Research Laboratory, Space Vehicles Directorate 29 Randolph Road, Hanscom AFB, MA 01731 United States
AU: Sharma, R D
EM: ramesh.sharma@hanscom.af.mil
AF: Air Force Research Laboratory, Space Vehicles Directorate 29 Randolph Road, Hanscom AFB, MA 01731 United States
AB: 5.3 μm emission from nitric oxide was observed by the MIPAS instrument on board the ENVISAT satellite under auroral and quiescent conditions in 2003. The very high spectral resolution of the instrument (0.035 cm^-1 unapodized) permits detailed study of the rotational and spin-orbit distributions of NO in the upper atmosphere. Spectral modeling of the NO(Δv = 1) fundamental band emissions was performed and compared with the results of a non-LTE atmospheric model. In the MIPAS data taken during the October/November solar storm, strong NO signal levels and increased rotational temperatures indicated high levels of auroral activity. The two primary sources of NO(v = 1) in the thermosphere are the collisional excitation of NO(v = 0) by O atoms and the chemical reactions of N(⁴S) and N(²D) atoms with O₂. Auroral activity leads to increased production of N(⁴S) and N(²D) atoms, resulting in enhanced chemical formation of NO. The NO(v = 1) spin-orbit distributions were found to be subthermal for all measurements. Variations in the NO spin-orbit ratios indicate that NO(v = 1) produced by N + O₂ has a hotter spin-orbit distribution than NO(v = 1) produced by O atom collisional pumping. Spin-orbit relaxation is slower than rotational relaxation, and therefore the NO spin-orbit ratio may be useful as a signature of the NO formation mechanism.
DE: 0310 Airglow and aurora
DE: 0317 Chemical kinetic and photochemical properties
DE: 0355 Thermosphere--composition and chemistry
SC: SPA-Aeronomy [SA]
MN: 2005 Joint Assembly