Influence of the Precipitating Energetic Particles on Atmospheric Chemistry and Climate

Rozanov, Eugene; Calisto, M.; Egorova, ‪Tatiana; Peter, Thomas; Schmutz, W.

doi:10.1007/978-94-007-4327-4_12

Cited by 42 publications

(58 citation statements)

References 60 publications

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“…The auroral electrons are often isotropic, and a positive correlation between geomagnetic activity or particle precipitation and the NO x composition is fairly well established [ Baker et al ., ; Barth et al ., ; Sætre et al ., , ; Hendrickx et al ., ]. The role of the more energetic electron precipitation (EEP) in changing the chemistry of the middle atmosphere (50–100 km) is, on the other hand, still an outstanding question [ Rozanov et al ., ; Sinnhuber et al ., ]. These often highly anisotropic electrons originate from the outer radiation belts, and their precipitation to the atmosphere is related to complex wave‐particle interactions mostly confined to subauroral latitudes.…”

Section: Introductionmentioning

confidence: 99%

Energetic electron precipitation into the middle atmosphere—Constructing the loss cone fluxes from MEPED POES

et al. 2016

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The impact of energetic electron precipitation (EEP) on the chemistry of the middle atmosphere (50–90 km) is still an outstanding question as accurate quantification of EEP is lacking due to instrumental challenges and insufficient pitch angle coverage of current particle detectors. The Medium Energy Proton and Electron Detectors (MEPED) instrument on board the NOAA/Polar Orbiting Environmental Satellites (POES) and MetOp spacecraft has two sets of electron and proton telescopes pointing close to zenith (0°) and in the horizontal plane (90°). Using measurements from either the 0° or 90° telescope will underestimate or overestimate the bounce loss cone flux, respectively, as the energetic electron fluxes are often strongly anisotropic with decreasing fluxes toward the center of the loss cone. By combining the measurements from both telescopes with electron pitch angle distributions from theory of wave‐particle interactions in the magnetosphere, a complete bounce loss cone flux is constructed for each of the electron energy channels >50 keV, >100 keV, and >300 keV. We apply a correction method to remove proton contamination in the electron counts. We also account for the relativistic (>1000 keV) electrons contaminating the proton detector at subauroral latitudes. This gives us full range coverage of electron energies that will be deposited in the middle atmosphere. Finally, we demonstrate the method's applicability on strongly anisotropic pitch angle distributions during a weak geomagnetic storm in February 2008. We compare the electron fluxes and subsequent energy deposition estimates to OH observations from the Microwave Limb Sounder on the Aura satellite substantiating that the estimated fluxes are representative for the true precipitating fluxes impacting the atmosphere.

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Section: Introductionmentioning

confidence: 99%

Energetic electron precipitation into the middle atmosphere—Constructing the loss cone fluxes from MEPED POES

et al. 2016

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“…HO x and NO x gasses will destroy ozone in catalytic reactions (Andersson et al, ; Sinnhuber et al, ), and it is speculated that the subsequent change in temperature might alter stratospheric winds and wave propagation. Model simulations and meteorological reanalysis studies suggest that the energetic particle precipitation (EPP)‐induced chemical‐dynamical coupling could impact regional surface level climate at high latitudes during winter (Baumgaertner et al, ; Maliniemi et al, ; Rozanov et al, , ; Seppälä et al, , ).…”

Section: Introductionmentioning

confidence: 99%

Intercomparison of the POES/MEPED Loss Cone Electron Fluxes With the CMIP6 Parametrization

et al. 2019

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Quantitative measurements of medium energy electron (MEE) precipitation (>40 keV) are a key to understand the total effect of particle precipitation on the atmosphere. The Medium Energy Proton and Electron Detector (MEPED) instrument on board the NOAA/Polar Orbiting Environmental Satellites (POES) has two sets of electron telescopes pointing ~0° and ~90° to the local vertical. Pitch angle anisotropy, which varies with particle energy, location, and geomagnetic activity, makes the 0° detector measurements a lower estimate of the flux of precipitating electrons. In the solar forcing recommended for Coupled Model Intercomparison Project (CMIP) 6 (v3.2) MEE precipitation is parameterized by Ap based on 0° detector measurements hence providing a general underestimate of the flux level. In order to assess the accuracy of the Ap model, we compare the modeled electron fluxes with estimates of the loss cone fluxes using both detectors in combination with electron pitch angle distributions from theory of wave‐particle interactions. The Ap model falls short in respect to reproducing the flux level and variability associated with strong geomagnetic storms (Ap > 40) as well as the duration of corotating interaction region storms causing a systematic bias within a solar cycle. As the Ap‐parameterized fluxes reach a plateau for Ap > 40, the model's ability to reflect the flux level of previous solar cycles associated with generally higher Ap values is questioned. The objective of this comparison is to understand the potential uncertainty in the energetic particle precipitation applying the CMIP6 particle energy input in order to assess its subsequent impact on the atmosphere.

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“…EPP can significantly change the properties, dynamics, and chemical composition of the upper and middle atmosphere. The chemical changes induced by EPP have long been found to have implications for the production of atmospheric nitric oxides (NO x ) and reactive hydrogen oxides (HO x ; e.g., Sinnhuber et al, ), both of which can lead to significant ozone losses in the stratosphere and mesosphere (e.g., Randall et al, ; Rozanov et al, ; Seppälä et al, ). HO x produced in the mesosphere has a short lifetime but can cause daylong ozone depletion of up to 90% (Andersson et al, ).…”

Section: Introductionmentioning

confidence: 99%

Pitch Angle Dependence of Energetic Electron Precipitation: Energy Deposition, Backscatter, and the Bounce Loss Cone

Marshall

Bortnik

2018

JGR Space Physics

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Quantifying radiation belt precipitation and its consequent atmospheric effects requires an accurate assessment of the pitch angle distribution of precipitating electrons, as well as knowledge of the dependence of the atmospheric deposition on that distribution. Here Monte Carlo simulations are used to investigate the effects of the incident electron energy and pitch angle on precipitation for bounce period time scales, and the implications for both the loss from the radiation belts and the deposition in the upper atmosphere. Simulations are conducted at discrete energies and pitch angles to assess the dependence on these parameters of the atmospheric energy deposition profiles and to estimate the backscattered particle distributions. We observe that the atmospheric response is both energy and pitch angle dependent. These effects together result in an energy‐dependent bounce loss cone angle, which can vary by 2–3° with particle energy when considered at low‐Earth orbit. This modeling also predicts that a significant fraction of the input electron distribution will be backscattered and should be observable by low‐Earth‐orbiting satellites as field‐aligned beams emerging from the atmosphere at energies lower than the input distribution and having pitch angles distributed just inside the loss cone.

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Influence of the Precipitating Energetic Particles on Atmospheric Chemistry and Climate

Cited by 42 publications

References 60 publications

Energetic electron precipitation into the middle atmosphere—Constructing the loss cone fluxes from MEPED POES

Energetic electron precipitation into the middle atmosphere—Constructing the loss cone fluxes from MEPED POES

Intercomparison of the POES/MEPED Loss Cone Electron Fluxes With the CMIP6 Parametrization

Pitch Angle Dependence of Energetic Electron Precipitation: Energy Deposition, Backscatter, and the Bounce Loss Cone

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