Enhancement of N&lt;sub&gt;2&lt;/sub&gt;O during the October–November 2003 solar proton events

Abstract. In this paper we present evidence of enhanced N2O concentrations in the upper stratosphere/lower mesosphere polar regions after the solar proton events that occurred during October–November 2003. The observations were performed by the MIPAS instrument on the Envisat satellite. Simulations performed using the Canadian Middle Atmospheric Model (CMAM) show that such enhancements are most likely produced by the reaction of N(4S) with NO2, both of which species are largely enhanced just after the solar proton events in the winter polar night.

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The effect of Forbush decreases on the polar-night HOx concentration

10.5194/egusphere-egu21-7498 ◽

2021 ◽

Author(s):

Irina Mironova

Keyword(s):

Forbush Decrease ◽

Cosmic Ray ◽

Solar Proton ◽

Polar Night ◽

Forbush Decreases ◽

Ozone Loss ◽

Solar Proton Events ◽

Hydrogen Oxide ◽

The Impact ◽

Ionization Rates

<div> <div> <div> <p>It is well-known that energetic particle precipitations during solar proton events increase ionization rates in the middle atmosphere enhancing the production of hydrogen oxide radicals (HOx) involved in the catalytic ozone destruction cycle. There are many studies where the contribution of energetic particles to the formation of hydrogen oxide radicals and ozone loss has been widely investigated. However, until now, there was no solid evidence that the reduction in galactic cosmic ray fluxes during a magnetic storm, known as Forbush-effect, directly and noticeably affects the polar-night stratospheric chemistry.<br>Here, the impact of the Forbush decrease on the behaviour of hydrogen oxide radicals was explored using the chemistry-climate model SOCOL.<br>We found that hydrogen oxide radical lost about half of its concentration over the polar boreal night stratosphere owing to a reduction in ionization rates caused by Forbush decreases after solar proton events occurred on 17 and 20 of January 2005. A robust response in ozone was not found. There is not any statistically significant response in (NOx) on Forbush decrease events as well as over summertime in the southern polar region.<br>The results of this study can be used to increase the veracity of ozone loss estimation if stronger Forbush events can have a place.</p> <p>Reference: Mironova I, Karagodin-Doyennel A and Rozanov E (2021) , The effect of Forbush decreases on the polar-night HOx concentration affecting stratospheric ozone. Front. Earth Sci. 8:618583. doi: 10.3389/feart.2020.618583</p> <p>https://www.frontiersin.org/articles/10.3389/feart.2020.618583/full</p> <p>The study was supported by the Russian Science Foundation grant (RSF project No. 20-67-46016).</p> </div> </div> </div>

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The Effect of Forbush Decreases on the Polar-Night HOx Concentration Affecting Stratospheric Ozone

Frontiers in Earth Science ◽

10.3389/feart.2020.618583 ◽

2021 ◽

Vol 8 ◽

Author(s):

Irina Mironova ◽

Arseniy Karagodin-Doyennel ◽

Eugene Rozanov

Keyword(s):

Forbush Decrease ◽

Cosmic Ray ◽

Solar Proton ◽

Polar Night ◽

Forbush Decreases ◽

Ozone Loss ◽

Solar Proton Events ◽

Hydrogen Oxide ◽

The Impact ◽

Ionization Rates

It is well-known that energetic particle precipitations during solar proton events increase ionization rates in the middle atmosphere enhancing the production of hydrogen oxide radicals (HOx) involved in the catalytic ozone destruction cycle. There are many studies where the contribution of energetic particles to the formation of hydrogen oxide radicals and ozone loss has been widely investigated. However, until now, there was no solid evidence that the reduction in galactic cosmic ray fluxes during a magnetic storm, known as Forbush-effect, directly and noticeably affects the polar-night stratospheric chemistry. Here, the impact of the Forbush decrease on the behavior of hydrogen oxide radicals was explored using the chemistry-climate model SOCOLv2. We found that hydrogen oxide radical lost about half of its concentration over the polar boreal night stratosphere owing to a reduction in ionization rates caused by Forbush decreases after solar proton events occurred on 17 and 20 of January 2005. The robust response in ozone was not found. There is not any statistically significant response in (NOx) on Forbush decrease events as well as over summer time in the southern polar region. The results of this study can be used to increase the veracity of ozone loss estimation if stronger Forbush events can have place.

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Impact of January 2005 solar proton events on chlorine species

Atmospheric Chemistry and Physics ◽

10.5194/acp-12-4159-2012 ◽

2012 ◽

Vol 12 (9) ◽

pp. 4159-4179 ◽

Cited By ~ 17

Author(s):

A. Damiani ◽

B. Funke ◽

D. R. Marsh ◽

M. López-Puertas ◽

M. L. Santee ◽

...

Keyword(s):

Geographic Distribution ◽

Climate Model ◽

Temporal Evolution ◽

Michelson Interferometer ◽

Solar Proton ◽

Active Chlorine ◽

High Latitudes ◽

Polar Night ◽

Solar Proton Events ◽

Terminator Region

Abstract. Sudden changes in stratospheric chlorine species in the polar northern atmosphere, caused by the Solar Proton Events (SPEs) of 17 and 20 January 2005, have been investigated and compared with version 4 of the Whole Atmosphere Community Climate Model (WACCM4). We used Aura Microwave Limb Sounder (MLS) measurements to monitor the variability of ClO, HCl, HOCl and Michelson Interferometer for Passive Atmospheric Sounder (MIPAS) on ENVISAT to retrieve ClONO2. SPE-induced chlorine activation has been identified. HCl decrease occurred at nearly all the investigated altitudes (i.e., 10–0.5 hPa) with the strongest decrease (of about 0.25 ppbv) on 21 January. HOCl was found to be the main active chlorine species under nighttime conditions (with increases of more than 0.2 ppbv) whereas both HOCl and ClO enhancements (about 0.1 ppbv) have been observed at the polar night terminator. Further, small ClO decreases (of less than 0.1 ppbv) and ClONO2 enhancements (about 0.2 ppbv) have been observed at higher latitudes (i.e., at nighttime) roughly above 2 hPa. While WACCM4 reproduces most of the SPE-induced variability in the chlorine species fairly well, in some particular regions discrepancies between the modeled and measured temporal evolution of the abundances of chlorine species were found. HOCl changes are modelled very well with respect to both magnitude and geographic distribution. ClO decreases are reproduced at high latitudes, whereas ClO enhancements in the terminator region are underestimated and attributed to background variations. WACCM4 also reproduces the HCl depletion in the mesosphere but it does not show the observed decrease below about 2 hPa. Finally, WACCM4 simulations indicate that the observed ClONO2 increase is dominated by background variability, although SPE-induced production might contribute by 0.1 ppbv.

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Impact of January 2005 solar proton events on chlorine species

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-12-1935-2012 ◽

2012 ◽

Vol 12 (1) ◽

pp. 1935-1978 ◽

Cited By ~ 1

Author(s):

A. Damiani ◽

B. Funke ◽

D. R. Marsh ◽

M. López-Puertas ◽

M. L. Santee ◽

...

Keyword(s):

Geographic Distribution ◽

Climate Model ◽

Temporal Evolution ◽

Michelson Interferometer ◽

Solar Proton ◽

Active Chlorine ◽

High Latitudes ◽

Polar Night ◽

Solar Proton Events ◽

Terminator Region

Abstract. Sudden changes in stratospheric chlorine species in the polar northern atmosphere, caused by the Solar Proton Events (SPEs) of 17 and 20 January 2005, have been investigated and compared with version 4 of the Whole Atmosphere Community Climate Model (WACCM4). We used Aura Microwave Limb Sounder (MLS) measurements to monitor the variability of ClO, HCl, HOCl and Michelson Interferometer for Passive Atmospheric Sounder (MIPAS) on ENVISAT to retrieve ClONO2. SPE-induced chlorine activation has been identified. HCl decrease occurred at nearly all the investigated altitudes with the lowest values (of less than 0.25 ppbv) on 21 January. HOCl was found to be the main active chlorine species under nighttime conditions (with increases of more than 0.2 ppbv) whereas both HOCl and ClO enhancements (about 0.1 ppbv) have been observed at the polar night terminator. Further, small ClO decreases (of less than 0.1 ppbv) and ClONO2 enhancements (about 0.2 ppbv) have been observed at higher latitudes (i.e., at nighttime) roughly above 2 hPa. While WACCM4 reproduces most of the SPE-induced variability in the chlorine species fairly well, in some particular regions discrepancies between the modeled and measured temporal evolution of the abundances of chlorine species were found. HOCl changes are modelled very well with respect to both magnitude and geographic distribution. ClO decreases are reproduced at high latitudes, whereas ClO enhancements in the terminator region are underestimated and attributed to background variations. WACCM4 also reproduces the HCl depletion in the mesosphere but it does not show the observed decrease below about 2 hPa. Finally, WACCM4 simulations indicate that the observed ClONO2 increase is dominated by background variability, although SPE-induced production might contribute by 0.1 ppbv.

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