Effect of solar proton events on the middle atmosphere during the past two solar cycles as computed using a two‐dimensional model

Jackman, Charles H.; Douglass, Anne R.; Rood, Richard B.; McPeters, Richard D.; Meade, Paul E.

doi:10.1029/jd095id06p07417

Cited by 138 publications

(87 citation statements)

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“…The ozone response due to very large SPEs is fairly rapid and substantial and has been observed during and after numerous events to date (e.g., Weeks et al, 1972;Heath et al, 1977;McPeters et al, 1981;Thomas et al, 1983;Solomon et al, 1982;McPeters and Jackman, 1985;Jackman et al, 1990Jackman et al, , 1995Jackman et al, , 2001Jackman et al, , 2005bJackman et al, , 2008Jackman et al, , 2011Jackman et al, , 2014 Decreases in mesospheric and upper stratospheric ozone are mostly caused by SPE-induced HO x increases, which were predicted to occur over 42 years ago (e.g., see Swider and Keneshea, 1973). Direct measurements of SPE-caused OH and HO 2 enhancements have confirmed these early predictions (e.g., Damiani et al, 2008;Jackman et al, 2011Jackman et al, , 2014).…”

Section: Solar Protonsmentioning

confidence: 99%

“…Additionally, N 2 O has been measured to increase as a result of large SPEs . (Jackman et al, 1990) and IMP 8 was used for the fluxes from 1974 to 1993 (Vitt and Jackman, 1996). The National Oceanic and Atmospheric Administration (NOAA) Geostationary Operational Environmental Satellites (GOES) were used for proton fluxes from 1994 to 2014 (e.g., Jackman et al, 2005aJackman et al, , 2014.…”

Section: Solar Protonsmentioning

confidence: 99%

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Solar forcing for CMIP6 (v3.2)

et al. 2017

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Abstract. This paper describes the recommended solar forcing dataset for CMIP6 and highlights changes with respect to CMIP5. The solar forcing is provided for radiative properties, namely total solar irradiance (TSI), solar spectral irradiance (SSI), and the F10.7 index as well as particle forcing, including geomagnetic indices Ap and Kp, and ionization rates to account for effects of solar protons, electrons, and galactic cosmic rays. This is the first time that a recommendation for solar-driven particle forcing has been provided for a CMIP exercise. The solar forcing datasets are provided at daily and monthly resolution separately for the CMIP6 preindustrial control, historical (1850CMIP6 preindustrial control, historical ( -2014, and future (2015-2300) simulations. For the preindustrial control simulation, both constant and time-varying solar forcing components are provided, with the latter including variability on 11-year and shorter timescales but no long-term changes. For the future, we provide a realistic scenario of what solar behavior could be, as well as an additional extreme Maunderminimum-like sensitivity scenario. This paper describes the forcing datasets and also provides detailed recommendations as to their implementation in current climate models.For the historical simulations, the TSI and SSI time series are defined as the average of two solar irradiance models that are adapted to CMIP6 needs: an empirical onePublished by Copernicus Publications on behalf of the European Geosciences Union. A new and lower TSI value is recommended: the contemporary solar-cycle average is now 1361.0 W m −2 . The slight negative trend in TSI over the three most recent solar cycles in the CMIP6 dataset leads to only a small global radiative forcing of −0.04 W m −2 . In the 200-400 nm wavelength range, which is important for ozone photochemistry, the CMIP6 solar forcing dataset shows a larger solar-cycle variability contribution to TSI than in CMIP5 (50 % compared to 35 %).We compare the climatic effects of the CMIP6 solar forcing dataset to its CMIP5 predecessor by using timeslice experiments of two chemistry-climate models and a reference radiative transfer model. The differences in the long-term mean SSI in the CMIP6 dataset, compared to CMIP5, impact on climatological stratospheric conditions (lower shortwave heating rates of −0.35 K day −1 at the stratopause), cooler stratospheric temperatures (−1.5 K in the upper stratosphere), lower ozone abundances in the lower stratosphere (−3 %), and higher ozone abundances (+1.5 % in the upper stratosphere and lower mesosphere). Between the maximum and minimum phases of the 11-year solar cycle, there is an increase in shortwave heating rates (+0.2 K day −1 at the stratopause), temperatures (∼ 1 K at the stratopause), and ozone (+2.5 % in the upper stratosphere) in the tropical upper stratosphere using the CMIP6 forcing dataset. This solar-cycle response is slightly larger, but not statistically significantly different from that for the CMIP5 forcing dataset.CMIP6 models wi...

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Section: Solar Protonsmentioning

confidence: 99%

Section: Solar Protonsmentioning

confidence: 99%

Solar forcing for CMIP6 (v3.2)

et al. 2017

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“…This model was first discussed over 20 yr ago (Douglass et al, 1989;Jackman et al, 1990) and has undergone extensive improvements over the years (e.g., Considine et al, 1994;Jackman et al, 1996;Fleming et al, 1999Fleming et al, , 2007Fleming et al, , 2011. The vertical range of the model, equally spaced in log pressure, is from the ground to approximately 92 km (0.0024 hPa) with a 1 km grid spacing.…”

Section: Description Of the Gsfc 2-d Modelmentioning

confidence: 99%

“…Although SPEs and their middle atmospheric constituent influences have been studied before (e.g., Swider and Keneshea, 1973;Heath et al, 1977;Solomon et al, 1981;McPeters and Jackman, 1985;Randall et al, 2001;López-Puertas et al, 2005a;von Clarmann et al, 2005;Verronen et al, , 2008Verronen et al, , 2011aKrivolutsky et al, 2006;Funke et al, 2011;Jackman et al, 1990Jackman et al, , 2001Jackman et al, , 2008Jackman et al, , 2009Sinnhuber et al, 2012), each new event offers a chance to investigate the SPE-caused atmospheric perturbation under somewhat different conditions. Also, such events have been shown to cause some longer lasting stratospheric changes (e.g., Randall et al, 2001;Jackman et al, 2008Jackman et al, , 2009) and need to be considered within the context of other ongoing stratospheric changes (WMO, 2011).…”

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confidence: 99%

Middle atmospheric changes caused by the January and March 2012 solar proton events

Jackman

Randall²,

Harvey³

et al. 2014

Atmos. Chem. Phys.

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Abstract. The recent 23-30 January and 7-11 March 2012 solar proton event (SPE) periods were substantial and caused significant impacts on the middle atmosphere. These were the two largest SPE periods of solar cycle 24 so far. The highly energetic solar protons produced considerable ionization of the neutral atmosphere as well as HO x (H, OH, HO 2 ) and NO x (N, NO, NO 2 ). We compute a NO x production of 1.9 and 2.1 Gigamoles due to these SPE periods in January and March 2012, respectively, which places these SPE periods among the 12 largest in the past 50 yr. Aura Microwave Limb Sounder (MLS) observations of the peroxy radical, HO 2 , show significant enhancements of > 0.9 ppbv in the northern polar mesosphere as a result of these SPE periods. Both MLS measurements and Goddard Space Flight Center (GSFC) two-dimensional (2-D) model predictions indicated middle mesospheric ozone decreases of > 20 % for several days in the northern polar region with maximum depletions > 60 % over 1-2 days as a result of the HO x produced in both the January and March 2012 SPE periods. The SCISAT-1 Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE) and the Envisat Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) instruments measured NO and NO 2 (∼ NO x ), which indicated enhancements of over 20 ppbv in most of the northern polar mesosphere for several days as a result of these SPE periods. The GSFC 2-D model and the Global Modeling Initiative three-dimensional chemistry and transport model were used to predict the medium-term (∼ months) influence and showed that the polar middle atmospheric ozone was most affected by these solar events in the Southern Hemisphere due to the increased downward motion in the fall and early winter. The downward transport moved the SPE-produced NO y to lower altitudes and led to predicted modest destruction of ozone (5-13 %) in the upper stratosphere days to weeks after the March 2012 event. Polar total ozone reductions were predicted to be a maximum of 1.5 % in 2012 due to these SPEs.

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“…The nitrates are produced by the direct ionization of the upper polar atmosphere by SEP protons with energy nominally >30 MeV (Jackman et al 1990(Jackman et al , 2001. Especially in the winter hemisphere, the nitrates are precipitated within 2-6 weeks in a snow layer that is eventually compressed into the polar fm and ice layers.…”

Section: Years Of Sep Eventsmentioning

confidence: 99%

Solar energetic particle variations

Reames

2004

Advances in Space Research

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In the largest solar energetic-particle (SEP) events, acceleration occurs at shock waves driven out from the Sun by coronal mass ejections (CMEs). In fact, the highest proton intensities directly measured near Earth at energies up to -1 GeV occur at the time of passage of shocks, which arrive about a day after the CMEs leave the Sun. CMEdriven shocks expanding across magnetic fields can fill over half of the heliosphere with SEPs. Proton-generated Alfven waves trap particles near the shock for efficient acceleration but also throttle the intensities at Earth to the "streaming limit" early in the events. At high energies, particles begin to leak from the shock and the spectrum rolls downward to form an energy-spectral "knee" that can vary in energy from -1 MeV to -1 GeV in different events. All of these factors affect the radiation dose as a function of depth and latitude in the Earth's atmosphere and the risk to astronauts and equipment in space. SEP ionization of the polar atmosphere produces nitrates that precipitate to become trapped in the polar ice. Observations of nitrate deposits in ice cores reveal individual large SEP events and extend back -400 years. Unlike sunspots, SEP events follow the -80-100-year Gleissberg cycle rather faithfully and are now at a minimum in that cycle. The largest SEP event in the last 400 years appears to be related to the flare observed by Carrington in 1859, but the probability of SEP events with such large fluences falls off sharply because of the streaming limit. INTRODUCTIONThe solar wind, which blows at speeds of 300 to 800 W s , corresponds to proton energies of 0.5 to 3 keV. The protons in solar energetic-particle (SEP) events have energy spectra that span the region from about 10 keV to >10 GeV. In large SEP events, omni-directional fluences of >30 MeV protons can exceed 10"

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Effect of solar proton events on the middle atmosphere during the past two solar cycles as computed using a two‐dimensional model

Cited by 138 publications

References 40 publications

Solar forcing for CMIP6 (v3.2)

Solar forcing for CMIP6 (v3.2)

Middle atmospheric changes caused by the January and March 2012 solar proton events

Solar energetic particle variations

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