Impact of EMIC-Wave Driven Electron Precipitation on the Radiation Belts and the Atmosphere

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378289%3A_____%2F21%3A00559270" target="_blank" >RIV/68378289:_____/21:00559270 - isvavai.cz</a>

Výsledek na webu

<a href="https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020JA028671" target="_blank" >https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020JA028671</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1029/2020JA028671" target="_blank" >10.1029/2020JA028671</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Impact of EMIC-Wave Driven Electron Precipitation on the Radiation Belts and the Atmosphere

Popis výsledku v původním jazyce

In recent years, there has been a growing body of direct experimental evidence demonstrating electromagnetic ion cyclotron (EMIC) waves driving energetic electron precipitation (EEP) at unexpectedly low, sub-MeV energies-as low as only a few hundred keV. EMIC-wave driven scattering at these energies has important ramifications for our understanding of not only radiation belt electron dynamics, but also the importance of EMIC-driven EEP to the chemical balance of the Earth's atmosphere. In this study, we use three experimentally derived EMIC-driven EEP flux spectra to investigate the impact of this precipitation on trapped radiation belt fluxes. In doing so, we resolve an apparent contradiction with earlier results derived from trapped electron flux populations that suggested EMIC waves only caused significant scattering at ultrarelativistic energies. We show that strong sub-MeV EEP measurements are not necessarily mutually exclusive with a strongly relativistic-only trapped flux response, as the sub-MEV peak precipitation is comparatively much smaller than the trapped population at those energies. Using a further six EEP spectra, we also demonstrate that EMIC-driven EEP can generate significant ionization of the Earth's atmosphere above 40 km, leading to the loss of mesospheric ozone. We find poor correlation between EMIC-driven EEP fluxes and geomagnetic activity proxies, such that EMIC-driven EEP is likely to be poorly specified in the forcing factors of modern coupled-climate models.

Název v anglickém jazyce

Impact of EMIC-Wave Driven Electron Precipitation on the Radiation Belts and the Atmosphere

Popis výsledku anglicky

In recent years, there has been a growing body of direct experimental evidence demonstrating electromagnetic ion cyclotron (EMIC) waves driving energetic electron precipitation (EEP) at unexpectedly low, sub-MeV energies-as low as only a few hundred keV. EMIC-wave driven scattering at these energies has important ramifications for our understanding of not only radiation belt electron dynamics, but also the importance of EMIC-driven EEP to the chemical balance of the Earth's atmosphere. In this study, we use three experimentally derived EMIC-driven EEP flux spectra to investigate the impact of this precipitation on trapped radiation belt fluxes. In doing so, we resolve an apparent contradiction with earlier results derived from trapped electron flux populations that suggested EMIC waves only caused significant scattering at ultrarelativistic energies. We show that strong sub-MeV EEP measurements are not necessarily mutually exclusive with a strongly relativistic-only trapped flux response, as the sub-MEV peak precipitation is comparatively much smaller than the trapped population at those energies. Using a further six EEP spectra, we also demonstrate that EMIC-driven EEP can generate significant ionization of the Earth's atmosphere above 40 km, leading to the loss of mesospheric ozone. We find poor correlation between EMIC-driven EEP fluxes and geomagnetic activity proxies, such that EMIC-driven EEP is likely to be poorly specified in the forcing factors of modern coupled-climate models.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10305 - Fluids and plasma physics (including surface physics)

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2021

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Geophysical Research-Space Physics

ISSN

2169-9380

e-ISSN

2169-9402

Svazek periodika

126

Číslo periodika v rámci svazku

3

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

14

Strana od-do

e2020JA028671

Kód UT WoS článku

000636288800033

EID výsledku v databázi Scopus

2-s2.0-85103268121