scholarly journals Energetic electron precipitation into the middle atmosphere-Constructing the loss cone fluxes from MEPED POES

2016 ◽  
Vol 121 (6) ◽  
pp. 5693-5707 ◽  
Author(s):  
H. Nesse Tyssøy ◽  
M. I. Sandanger ◽  
L.-K. G. Ødegaard ◽  
J. Stadsnes ◽  
A. Aasnes ◽  
...  
Keyword(s):  
Middle Atmosphere ◽  
Energetic Electron ◽  
Electron Precipitation ◽  
Loss Cone

Solar wind structures and their effects on energetic electron precipitation

2021 ◽  
Author(s):  
Josephine Alessandra Salice ◽  
Hilde Nesse Tyssøy ◽  
Christine Smith-Johnsen ◽  
Eldho Midhun Babu
Keyword(s):  
Solar Wind ◽  
Ozone Concentration ◽  
High Speed ◽  
Climate Models ◽  
Middle Atmosphere ◽  
Energetic Electron ◽  
Accurate Estimate ◽  
Electron Precipitation ◽  
Loss Cone ◽  
Speed Solar Wind

<p>Energetic electron precipitation (EEP) into the Earth's atmosphere can collide with gases and deposit their energy there. The collisions between electrons and atmospheric gasses initiate several chemical reactions which can reduce the ozone concentration. Ozone is critically important in the middle atmosphere energy budget as changes in the ozone concentration impact temperature and winds. EEP is not fully understood in terms of how much energy is being deposited and what the associated drivers are. An accurate quantification of EEP has limitations due to instrumental challenges and therefore imposes limitations of the associated EEP parameterization into climate models. A solution to this problem is a better understanding of the driver processes of energetic electron acceleration and precipitation, alongside optimized data handling. In this study the bounce loss cone fluxes are inferred from EEP measurements by the Medium Energy Proton and Electron Detector (MEPED) on board the Polar Orbiting Environmental Satellite (POES) and the Meteorological Operational Satellite Program of Europe (METOP) at tens of keV to relativistic energies. It investigates EEP in contexts of different solar wind structures: high-speed solar wind streams (HSSs) and coronal mass ejections (CMEs), during an eleven-year period from 2004 – 2014. While today's chemistry climate models only provide snapshots of EEP, independent of context, this study aims to understand the context EEP is created in, which will allow a more accurate estimate of the EEP to be applied in atmospheric climate models.</p>

The link between solar wind structures, geomagnetic indices, and energetic electron precipitation

2020 ◽  
Author(s):  
Josephine Salice ◽  
Hilde Nesse Tyssøy ◽  
Christine Smith-Johansen ◽  
Eldho Midhun Babu
Keyword(s):  
Solar Wind ◽  
Ozone Concentration ◽  
High Speed ◽  
Climate Models ◽  
Middle Atmosphere ◽  
Energetic Electron ◽  
Accurate Estimate ◽  
Electron Precipitation ◽  
Loss Cone ◽  
Accurate Quantification

<p>Energetic electron precipitation (EEP) into the Earth’s atmosphere can collide with gases and deposit their energy there. The collisions between electrons and atmospheric gasses initiate several chemical reactions which can reduce the ozone concentration. Ozone is critically important in the middle atmosphere energy budget as changes in the ozone concentration impact temperature and winds. EEP is not fully understood in terms of how much energy is being deposited and what the associated drivers are.  An accurate quantification of EEP has limitations due to instrumental challenges and therefore imposes limitations of the associated EEP parameterization into climate models. A solution to this problem is a better understanding of the driver processes of energetic electron acceleration and precipitation, alongside optimized measurements. In this study the bounce loss cone fluxes are inferred from EEP measurements by MEPED on board NOAA/POES and EUMETSAT/METOP at tens of keV to relativistic energies. It investigates EEP in contexts of three different solar wind structures: high-speed streams, coronal mass ejections, and ambient or slow interstream solar wind, as well as geomagnetic activity. The study will focus on the year 2010 and aim to understand the context EEP is created in, which will allow a more accurate estimate of the EEP to be applied in atmospheric climate models</p>

scholarly journals Comparison between CNA and energetic electron precipitation: simultaneous observation by Poker Flat Imaging Riometer and NOAA satellite

2005 ◽  
Vol 23 (5) ◽  
pp. 1555-1563 ◽  
Author(s):  
Y.-M. Tanaka ◽  
M. Ishii ◽  
Y. Murayama ◽  
M. Kubota ◽  
H. Mori ◽  
...  
Keyword(s):  
Pitch Angle ◽  
Electron Flux ◽  
Energetic Electron ◽  
Energetic Particles ◽  
Electron Precipitation ◽  
Angle Distribution ◽  
Pitch Angle Distribution ◽  
Loss Cone ◽  
Isotropic Pitch ◽  
Trapped Electron

Abstract. The cosmic noise absorption (CNA) is compared with the precipitating electron flux for 19 events observed in the morning sector, using the high-resolution data obtained during the conjugate observations with the imaging riometer at Poker Flat Research Range (PFRR; 65.11° N, 147.42° W), Alaska, and the low-altitude satellite, NOAA 12. We estimate the CNA, using the precipitating electron flux measured by NOAA 12, based on a theoretical model assuming an isotropic pitch angle distribution, and quantitatively compare them with the observed CNA. Focusing on the eight events with a range of variation larger than 0.4dB, three events show high correlation between the observed and estimated CNA (correlation coefficient (r0)>0.7) and five events show low correlation (r0<0.5). The estimated CNA is often smaller than the observed CNA (72% of all data for 19 events), which appears to be the main reason for the low-correlation events. We examine the assumption of isotropic pitch angle distribution by using the trapped electron flux measured at 80° zenith angle. It is shown that the CNA estimated from the trapped electron flux, assuming an isotropic pitch angle distribution, is highly correlated with the observed CNA and is often overestimated (87% of all data). The underestimate (overestimate) of CNA derived from the precipitating (trapped) electron flux can be interpreted in terms of the anisotropic pitch angle distribution similar to the loss cone distribution. These results indicate that the CNA observed with the riometer may be quantitatively explained with a model based on energetic electron precipitation, provided that the pitch angle distribution and the loss cone angle of the electrons are taken into account. Keywords. Energetic particles, precipitating – Energetic particles, trapped – Ionosphere-magnetosphere interactions

scholarly journals Reactive nitrogen (NO<sub><i>y</i></sub>) and ozone responses to energetic electron precipitation during Southern Hemisphere winter

2019 ◽  
Vol 19 (14) ◽  
pp. 9485-9494 ◽  
Author(s):  
Pavle Arsenovic ◽  
Alessandro Damiani ◽  
Eugene Rozanov ◽  
Bernd Funke ◽  
Andrea Stenke ◽  
...  
Keyword(s):  
Southern Hemisphere ◽  
Climate Model ◽  
Middle Atmosphere ◽  
Stratospheric Ozone ◽  
Energetic Electron ◽  
Polar Vortex ◽  
Solar Proton ◽  
Electron Precipitation ◽  
Reactive Nitrogen ◽  
High Electron

Abstract. Energetic particle precipitation (EPP) affects the chemistry of the polar middle atmosphere by producing reactive nitrogen (NOy) and hydrogen (HOx) species, which then catalytically destroy ozone. Recently, there have been major advances in constraining these particle impacts through a parametrization of NOy based on high-quality observations. Here we investigate the effects of low (auroral) and middle (radiation belt) energy range electrons, separately and in combination, on reactive nitrogen and hydrogen species as well as on ozone during Southern Hemisphere winters from 2002 to 2010 using the SOCOL3-MPIOM chemistry-climate model. Our results show that, in the absence of solar proton events, low-energy electrons produce the majority of NOy in the polar mesosphere and stratosphere. In the polar vortex, NOy subsides and affects ozone at lower altitudes, down to 10 hPa. Comparing a year with high electron precipitation with a quiescent period, we found large ozone depletion in the mesosphere; as the anomaly propagates downward, 15 % less ozone is found in the stratosphere during winter, which is confirmed by satellite observations. Only with both low- and middle-energy electrons does our model reproduce the observed stratospheric ozone anomaly.

scholarly journals Reactive nitrogen (NO<sub><i>y</i></sub>) and ozone responses to energetic electron precipitation during Southern Hemisphere winter

2018 ◽  
Author(s):  
Pavle Arsenovic ◽  
Alessandro Damiani ◽  
Eugene Rozanov ◽  
Bernd Funke ◽  
Andrea Stenke ◽  
...  
Keyword(s):  
Southern Hemisphere ◽  
Climate Model ◽  
Middle Atmosphere ◽  
Stratospheric Ozone ◽  
Energetic Electron ◽  
Polar Vortex ◽  
Solar Proton ◽  
Electron Precipitation ◽  
Reactive Nitrogen ◽  
High Electron

Abstract. Energetic particle precipitation (EPP) affects the chemistry of the polar middle atmosphere by producing reactive nitrogen (NOy) and hydrogen (HOx) species, which then catalytically destroy ozone. Recently, there have been major advances in constraining these particle impacts through a parametrization based on high quality observations. Here we investigate the effects of low (auroral) and middle (radiation belt) energy range electrons, separately and in combination, on reactive nitrogen and hydrogen species as well as on ozone during Southern Hemisphere winters from 2002 to 2010 using the chemistry-climate model SOCOL3-MPIOM. Our results show that, in absence of solar proton events, low energy electrons produce the majority of NOy in the polar mesosphere and stratosphere. In the polar vortex, NOy subsides and affects ozone at lower altitudes, down to 10 hPa. Comparing a year with high electron precipitation with a quiescent period, we found large ozone depletion in the mesosphere; as the anomaly propagates downward, 15 % less ozone is found in the stratosphere during winter, which is confirmed by satellite observations. Only with both low and middle energy electrons, our model reproduces the observed stratospheric ozone anomaly.

scholarly journals Direct observations of nitric oxide produced by energetic electron precipitation into the Antarctic middle atmosphere

2011 ◽  
Vol 38 (20) ◽  
pp. n/a-n/a ◽  
Author(s):  
David A. Newnham ◽  
Patrick J. Espy ◽  
Mark A. Clilverd ◽  
Craig J. Rodger ◽  
Annika Seppälä ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Middle Atmosphere ◽  
Energetic Electron ◽  
Electron Precipitation ◽  
Direct Observations ◽  
The Antarctic

scholarly journals Will climate change increase ozone depletion from low-energy-electron precipitation?

2010 ◽  
Vol 10 (19) ◽  
pp. 9647-9656 ◽  
Author(s):  
A. J. G. Baumgaertner ◽  
P. Jöckel ◽  
M. Dameris ◽  
P. J. Crutzen
Keyword(s):  
Climate Change ◽  
Geomagnetic Activity ◽  
Climate Model ◽  
Middle Atmosphere ◽  
Energetic Electron ◽  
Electron Precipitation ◽  
Change Scenario ◽  
Residual Circulation ◽  
Ozone Loss ◽  
Winter Time

Abstract. We investigate the effects of a strengthened stratospheric/mesospheric residual circulation on the transport of nitric oxide (NO) produced by energetic particle precipitation. During periods of high geomagnetic activity, energetic electron precipitation (EEP) is responsible for winter time ozone loss in the polar middle atmosphere between 1 and 6 hPa. However, as climate change is expected to increase the strength of the Brewer-Dobson circulation including extratropical downwelling, the enhancements of EEP NOx concentrations are expected to be transported to lower altitudes in extratropical regions, becoming more significant in the ozone budget. Changes in the mesospheric residual circulation are also considered. We use simulations with the chemistry climate model system EMAC to compare present day effects of EEP NOx with expected effects in a climate change scenario for the year 2100. In years of strong geomagnetic activity, similar to that observed in 2003, an additional polar ozone loss of up to 0.4 μmol/mol at 5 hPa is found in the Southern Hemisphere. However, this would be approximately compensated by an ozone enhancement originating from a stronger poleward transport of ozone from lower latitudes caused by a strengthened Brewer-Dobson circulation, as well as by slower photochemical ozone loss reactions in a stratosphere cooled by risen greenhouse gas concentrations. In the Northern Hemisphere the EEP NOx effect appears to lose importance due to the different nature of the climate-change induced circulation changes.

Statistical Distribution of Energetic Electron Precipitation due to Hiss Waves In the Earth’s Inner Magnetosphere

2021 ◽  
Author(s):  
Qianli Ma
Keyword(s):  
Energy Flux ◽  
Pitch Angle ◽  
Energetic Electron ◽  
Statistical Distribution ◽  
Electron Precipitation ◽  
Characteristic Energy ◽  
Loss Cone ◽  
Inner Magnetosphere ◽  
The Earth ◽  
Chorus Waves

&lt;p&gt;We investigate the statistical distribution of energetic electron precipitation from the equatorial magnetosphere due to hiss waves in the plasmasphere and plumes. Using Van Allen Probes measurements, we calculate the pitch angle diffusion coefficients at the pitch angle of bounce loss cone, and evaluate the energy spectrum of precipitating electron flux using quasi-linear theory. Our ~6.5 years survey shows that, during disturbed times, the plasmaspheric hiss mostly causes the electron precipitation at L &gt; 3 near the dayside in the plasmasphere, and hiss waves in plume cause the precipitation at L &gt; 5 near dayside and L &gt; 3.5 near the dusk side. The precipitating energy flux increases with increasing geomagnetic index, and is typically higher in the plasmaspheric plume than the plasmasphere. The characteristic energy of precipitation increases from ~20 keV at L = 6 to ~100 keV at L = 3, potentially causing the loss of electrons at several hundred keV. Although the total precipitating energy flux due to hiss waves is generally lower than the precipitation due to whistler mode chorus waves, the characteristic energy of precipitation due to hiss is higher, and the precipitation extends closer to the Earth.&lt;/p&gt;

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