Observation of Strong NO Gamma-Band Radiation Induced in Thin N₂-CO₂and N₂-H₂O Targets by Electron Impact and Its Possible Relation to the Auroral Chemistry of NO

Abstract

During current studies of emission from N, gas excited by 20 keV electrons using the High Frequency Deflection technique, it has been discovered that the addition of amounts of bo and co, to the N, target yields strong emission of NO A2z+-Xan (ybands). Possible me&anisms for formation of NO in electron-beam activated targets are investigated, and their relevance to auroral NO chemistry is discussed.

Mesospheric nitric oxide model from SCIAMACHY data

“…On the other hand, the concentration of air decreases with altitude. At this stage we do not have an unambiguous explanation of this behaviour, but it may be related to reaction pathways as laid out by Pendleton et al (1983), which would relate the NO concentrations to the CO 2 and H 2 O (or OH, respectively) profiles. The Lyman-α coefficients are all negative below 65 km.…”

“…At those altitudes and also in the mesosphere, NO participates in the "odd oxygen catalytic cycle which depletes ozone" (Crutzen, 1970). Additional dynamical processes also result in the strong downward transport of mesospheric air into the upper stratosphere, such as the strong downwelling that often occurs in the recovery phase of a sudden stratospheric warming (SSW) (Pérot et al, 2014; Published by Copernicus Publications on behalf of the European Geosciences Union.…”

“…Measurements from solar occultation instruments such as Scisat-1/ACE-FTS or AIM/SOFIE are limited in latitude and local time (sunrise and sunset). Global observations from sun-synchronously orbiting satellites are available from Envisat/MIPAS below 70 km daily and 42-172 km every 10 days (Funke et al, 2001(Funke et al, , 2005bBermejo-Pantaleón et al, 2011); from Odin/SMR between 45 and 115 km (Pérot et al, 2014;Kiviranta et al, 2018); or from Envisat/SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHar-toghraphY) between 60 and 90 km daily (Bender et al, 2017b) and 60-160 km every 15 days (Bender et al, 2013). Because the Odin and Envisat orbits are sun-synchronous, the measurement local times are fixed to around 06:00 and 18:00 (Odin) and 10:00 and 22:00 (Envisat).…”

Reply to "Interactive comment on “Mesospheric nitric oxide model from SCIAMACHY data” by Stefan Bender et al."

“…At those altitudes and also in the mesosphere, NO participates in the "odd oxygen catalytic cycle which depletes ozone" (Crutzen, 1970). Additional dynamical processes also result in the strong downward transport of mesospheric air into the upper stratosphere, such as the strong downwelling that often occurs in the recovery phase of a sudden stratospheric warming (SSW) (Pérot et al, 2014;S. Bender et al: SCIAMACHY mesosphere NO model Orsolini et al, 2017).…”

Reply to "Interactive comment on “Mesospheric nitric oxide model from SCIAMACHY data”."

“…At those altitudes and also in the mesosphere, NO participates in the "odd oxygen catalytic cycle which depletes ozone" (Crutzen, 1970). Additional dynamical processes also result in the strong downward transport of mesospheric air into the upper stratosphere, such as the strong downwelling that often occurs in the recovery phase of a sudden stratospheric warming (SSW) (Pérot et al, 2014;S. Bender et al: SCIAMACHY mesosphere NO model Orsolini et al, 2017).…”