scholarly journals NO x production due to energetic particle precipitation in the MLT region: Results from ion chemistry model studies

2014 ◽  
Vol 119 (3) ◽  
pp. 2137-2148 ◽  
Author(s):  
Holger Nieder ◽  
Holger Winkler ◽  
Daniel R. Marsh ◽  
Miriam Sinnhuber
Keyword(s):  
Energetic Particle ◽  
Ion Chemistry ◽  
Particle Precipitation ◽  
Model Studies ◽  
Energetic Particle Precipitation ◽  
Mlt Region

scholarly journals Impact of energetic particle precipitation on stratospheric polar constituents: an assessment using MIPAS data monitoring and assimilation

2009 ◽  
Vol 9 (5) ◽  
pp. 22459-22504
Author(s):  
A. Robichaud ◽  
R. Ménard ◽  
S. Chabrillat ◽  
J. de Grandpré ◽  
Y. J. Rochon ◽  
...  
Keyword(s):  
Gas Phase ◽  
Energetic Particle ◽  
Solar Proton ◽  
Significant Loss ◽  
Proton Event ◽  
Particle Precipitation ◽  
Gas Phase Chemistry ◽  
Energetic Particle Precipitation ◽  
Phase Chemistry ◽  
Assimilation System

Abstract. In 2003, strong geomagnetic events occurred which produced massive amounts of energetic particles penetrating the top of the atmospheric polar region, significantly perturbing its chemical state down to the middle stratosphere. These events and their effects are generally left unaccounted for in current models of stratospheric chemistry and large differences between observations and models are then noted. In this study, we use a coupled 3-D stratospheric dynamical-chemical model and assimilation system to ingest MIPAS temperature and chemical observations. The goal is to gain further understanding and to evaluate the impacts of EPP (energetic particle precipitation) on stratospheric polar chemistry. Moreover, we investigate the feasibility of assimilating valid "outlier" observations associated with such events. We focus our analysis on OmF (Observation minus Forecast) residuals as they filter out phenomena well reproduced by the model (such as gas phase chemistry, transport, diurnal and seasonal cycles) thus revealing a clear trace of the EPP. Inspection of OmF statistics in both the passive (without chemical assimilation) and active (with chemical assimilation) cases altogether provides a powerful diagnostic tool to assess the model and assimilation system. We also show that passive OmF can permit a satisfactory evaluation of the ozone partial column loss due to EPP effects. Results suggest a small but significant loss of 5–6 DU (Dobson Units) during an EPP-IE (EPP indirect effects) event in the Antarctic winter of 2003, and about only 1 DU for the SPE (solar proton event) of October/November 2003. Despite large differences between the model and MIPAS chemical observations (NO2, HNO3, CH4 and O3), we demonstrate that a careful assimilation of these constituents with only gas phase chemistry included in the model (i.e. no provision for EPP impacts) and with relaxed quality control nearly eliminated the short-term bias and significantly reduced the standard deviation error below 1 hPa.

scholarly journals Energetic particle precipitation in the Brazilian geomagnetic anomaly during the “Bastille Day storm” of July 2000

2006 ◽  
Vol 58 (5) ◽  
pp. 607-616 ◽  
Author(s):  
Masanori Nishino ◽  
Kazuo Makita ◽  
Kiyofumi Yumoto ◽  
Yoshizumi Miyoshi ◽  
Nelson J. Schuch ◽  
...  
Keyword(s):  
Energetic Particle ◽  
Particle Precipitation ◽  
Energetic Particle Precipitation ◽  
Geomagnetic Anomaly

scholarly journals Changes in upper mesospheric and lower thermospheric temperatures caused by energetic particle precipitation

2010 ◽  
Vol 115 (A10) ◽  
pp. n/a-n/a ◽  
Author(s):  
H. Nesse Tyssøy ◽  
J. Stadsnes ◽  
M. Sørbø ◽  
C. J. Mertens ◽  
D. S. Evans
Keyword(s):  
Energetic Particle ◽  
Particle Precipitation ◽  
Energetic Particle Precipitation

scholarly journals Climate Impact of Polar Mesospheric and Stratospheric Ozone Losses due to Energetic Particle Precipitation

2017 ◽  
Author(s):  
Katharina Meraner ◽  
Hauke Schmidt
Keyword(s):  
Radiative Forcing ◽  
Energetic Particle ◽  
Climate Model ◽  
Stratospheric Ozone ◽  
Energetic Particles ◽  
Climate Impact ◽  
Particle Precipitation ◽  
Ozone Loss ◽  
Mesospheric Ozone ◽  
Energetic Particle Precipitation

Abstract. Energetic particles enter the polar atmosphere and enhance the production of nitrogen oxides and hydrogen oxides in the winter stratosphere and mesosphere. Both components are powerful ozone destroyers. Recently, it has been inferred from observations that the direct effect of energetic particle precipitation (EPP) causes significant long-term mesospheric ozone variability. Satellites observe a decrease in mesospheric ozone by up to 34 % between EPP maximum and EPP minimum. Here, we analyze the climate impact of polar mesospheric and polar stratospheric ozone losses due to EPP in the coupled climate model MPI-ESM. Using radiative transfer modeling, we find that the radiative forcing of a mesospheric ozone loss during polar night is small. Hence, climate effects of a mesospheric ozone loss due to energetic particles seem unlikely. A stratospheric ozone loss due to energetic particles warms the winter polar stratosphere and subsequently weakens the polar vortex. However, those changes are small, and few statistically significant changes in surface climate are found.

scholarly journals Types of pulsating aurora: Comparison of model and EISCAT electron density observations

2021 ◽  
Author(s):  
Fasil Tesema ◽  
Noora Partamies ◽  
Daniel K. Whiter ◽  
Yasunobu Ogawa
Keyword(s):  
Energetic Particle ◽  
Energy Input ◽  
Energy Deposition ◽  
Common Phenomenon ◽  
Ion Chemistry ◽  
Satellite Measurements ◽  
Electron Densities ◽  
Significant Difference ◽  
Energetic Particle Precipitation ◽  
Good Agreement

Abstract. Energetic particle precipitation associated with pulsating aurora (PsA) can reach down to lower mesospheric altitude and deplete ozone. It is well documented that pulsating aurora is a common phenomenon during substorm recovery phases. This indicates that using magnetic indices to model the chemistry induced by PsA electrons could underestimate the energy deposition in the atmosphere. Integrating satellite measurements of precipitating electrons in models is considered to be an alternative way to account for such underestimation. One way to do this is to test and validate existing ion chemistry models using integrated measurements from satellite and ground-based observations. By using satellite measurements, an average/typical spectrum of PsA electrons can be constructed and used as an input in models to study the effects of the energetic electrons in the atmosphere. In this study, we compare electron densities from EISCAT radars with auroral ion chemistry and the energetics model by using pulsating aurora spectra derived from POES satellites as an energy input for the model. We found a good agreement between the model and EISCAT electron densities in the region dominated by patchy pulsating aurora. However, the magnitude of the observed electron densities suggests a significant difference in the flux of precipitating electrons for different pulsating aurora types (structures) observed.

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