The importance of energetic particle precipitation on the chemical composition of the middle atmosphere

Thorne, R. M.

doi:10.1007/bf01586448

Cited by 114 publications

(81 citation statements)

References 99 publications

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“…Strobel, 1971;Thorne, 1980;Rusch et al,production mechanism in the lower thermosphere, at the peak of the NO layer around 110 km, is the reaction of excited atomic nitrogen, N( 2 D), with O 2 . At higher altitudes, above ∼140 km, the dominant production mechanism is the strongly temperature dependent reaction of ground state atomic nitrogen, N( 4 S), with O 2 .…”

Section: Nitric Oxide In the Middle Atmospherementioning

confidence: 99%

Observations of NO in the upper mesosphere and lower thermosphere during ECOMA 2010

et al. 2012

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Abstract. In December 2010 the last campaign of the German-Norwegian sounding rocket project ECOMA (Existence and Charge state Of Meteoric smoke particles in the middle Atmosphere) was conducted from Andøya Rocket Range in northern Norway (69 • N, 16 • E) in connection with the Geminid meteor shower. The main instrument on board the rocket payloads was the ECOMA detector for studying meteoric smoke particles (MSPs) by active photoionization and subsequent detection of the produced charges (particles and photoelectrons). In addition to photoionizing MSPs, the energy of the emitted photons from the ECOMA flash-lamp is high enough to also photoionize nitric oxide (NO). Thus, around the peak of the NO layer, at and above the main MSP layer, photoelectrons produced by the photoionization of NO are expected to contribute to, or even dominate above the main MSP-layer, the total measured photoelectron current. Among the other instruments on board was a set of two photometers to study the O 2 (b 1 + g − X 3 − g ) Atmospheric band and NO 2 continuum nightglow emissions. In the absence of auroral emissions, these two nightglow features can be used together to infer NO number densities. This will provide a way to quantify the contribution of NO photoelectrons to the photoelectron current measured by the ECOMA instrument and, above the MSP layer, a simultaneous measurement of NO with two different and independent techniques. This work is still on-going due to the uncertainties, especially in the effort to quantitatively infer NO densities from the ECOMA photoelectron current, and the lack of simultaneous measurements of temperature and density for the photometric study. In this paper we describe these two techniques to infer NO densities and discuss the uncertainties. The peak NO number density inferred from the two photometers on ascent was 3.9 × 10 8 cm −3 at an altitude of about 99 km, while the concentration inferred from the ECOMA photoelectron measurement at this altitude was a factor of 5 smaller.

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Section: Nitric Oxide In the Middle Atmospherementioning

confidence: 99%

Observations of NO in the upper mesosphere and lower thermosphere during ECOMA 2010

et al. 2012

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“…Altitude of penetration for protons, electrons, and X-rays vertically incident at the top of the atmosphere as a function of particle energy (adapted from Fig. 2 of THORNE (1980) …”

Section: Overview Of Charged Particle Energy Depositionmentioning

confidence: 99%

“…Relativistic electron precipitations (REPs) have been proposed in the past 15 years to be important in contributing to the polar NOy budget of the mesosphere and upper stratosphere (THORNE, 1977;THORNE, 1980;BAKER et al, 1987;SHELDON et al, 1988;BAKER et al, 1988). The frequency and flux spectra of these REPS are still under discussion.…”

Section: Relativistic Electron Influencementioning

confidence: 99%

Effects of Energetic Particles on Minor Constituents of the Middle Atmosphere

Jackman

1991

J. geomagn. geoelec

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“…Production of reactive forms of hydrogen and nitrogen which lead to NO formation by precipitating outer zone electrons can significantly influence mesospheric chemistry and produce observable 0 3 depletion (Reagan, 1977;Thorne, 1977aThorne, , 1980. Intense relativistic electron precipitation (E > 1 MeV) can even contribute to NO production in the upper stratosphere (Thorne, 1977b;Baker et al, 1987, Callis et al, 1991b.…”

Section: Introductionmentioning

confidence: 99%

“…While changes in atmospheric chemistry due to electron precipitation have been investigated at higher geomagnetic latitudes (e.g. Thorne, 1975, 1976;Thorne, 1980;Baker et al, 1987;Callis et al, 1991a), the region below 60 ø, which is magnetically connected to the inner magnetosphere (L<4), has not been well characterized. Electron precipitation can easily be measured directly at higher latitudes during magnetically disturbed times (e.g.…”

Section: Introductionmentioning

confidence: 99%