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 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 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 Evidence for energetic particle precipitation and quasi-biennial oscillation modulations of the Antarctic NO<sub>2</sub> springtime stratospheric column from OMI observations

2020 ◽  
Vol 20 (11) ◽  
pp. 6259-6271
Author(s):  
Emily M. Gordon ◽  
Annika Seppälä ◽  
Johanna Tamminen
Keyword(s):  
Energetic Particle ◽  
Activity Index ◽  
Polar Vortex ◽  
Late Winter ◽  
Ozone Monitoring Instrument ◽  
Particle Precipitation ◽  
Quasi Biennial Oscillation ◽  
Energetic Particle Precipitation ◽  
The Antarctic ◽  
Biennial Oscillation

Abstract. Observations from the Ozone Monitoring Instrument (OMI) on the Aura satellite are used to study the effect of energetic particle precipitation (EPP, as proxied by the geomagnetic activity index, Ap) on the Antarctic stratospheric NO2 column in late winter–spring (August–December) during the period from 2005 to 2017. We show that the polar (60–90∘ S) stratospheric NO2 column is significantly correlated with EPP throughout the Antarctic spring, until the breakdown of the polar vortex in November. The strongest correlation takes place during years with the easterly phase of the quasi-biennial oscillation (QBO). The QBO modulation may be a combination of different effects: the QBO is known to influence the amount of the primary NOx source (N2O) via transport from the Equator to the polar region; and the QBO phase also affects polar temperatures, which may provide a link to the amount of denitrification occurring in the polar vortex. We find some support for the latter in an analysis of temperature and HNO3 observations from the Microwave Limb Sounder (MLS, on Aura). Our results suggest that once the background effect of the QBO is accounted for, the NOx produced by EPP significantly contributes to the stratospheric NO2 column at the time and altitudes when the ozone hole is present in the Antarctic stratosphere. Based on our findings, and the known role of NOx as a catalyst for ozone loss, we propose that as chlorine activation continues to decrease in the Antarctic stratosphere, the total EPP-NOx needs be accounted for in predictions of Antarctic ozone recovery.

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