Extreme Fluxes in SolarEnergetic Particle Events

© 2013 Leonty I. Miroshnichenko (IZMIRAN, SINP) and Rikho A. Nymmik (SINP)

N.V. Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation (IZMIRAN), Russian Academy of Sciences (RAS)

“Physics of Plasma in the Solar System”, Space Research Institute, Russian Academy of Sciences, Moscow, Russia, 5 February 2013

D.V. Skobeltsyn Institute of Nuclear Physics (SINP), M.V. Lomonosov Moscow State University (MSU), Moscow

Abstract• We analyze the data available on the largest solar proton events

(SPEs), or extreme solar energetic particle (SEP) events, for the period from 1561 up to now. Under consideration are observational, methodical and physical problems related to presentation of proton fluxes (fluences) near the Earth in the form of their energy spectra. Special attention is paid to the study of the form of distribution function for extreme fluxes (fluences) of SEPs by their sizes. Distribution of extremely large SEP fluxes is shown to have a probabilistic nature, so that a formulation “limit flux” does not contain a strict physical sense.

• The SEP fluxes may be only characterized by quite certain probabilities of their appearance, with a sharp break of the spectrum in the range of large fluences (or low probabilities). Modern data of observations and methods of investigations do not allow, for the present, to resolve precisely the problem of spectrum break and estimate maximum potentialities of solar accelerator(s). This restricts considerably an extrapolation of obtained results for the past and future, for the epochs with different levels of solar activity.

L.I. Miroshnichenko, R.A. Nymmik. Extreme fluxes in Solar Energetic Particle events: Methodical and physical limitations – Submitted to Radiation Measurements, 2012.

Motivations/Goals

• To plan and design safe and reliable pace missions, it is necessary to take into account the effects of the space radiation environment. The environment during large solar energetic particle (SEP) events poses greatest challenge to space missions. As a starting point for planning and design, a reference environment must be specified representing the most challenging environment to be encountered during the mission at some confidence level. The engineering challenge is then to find plans and mission design solutions that insure safe and reliable operations in this reference environment (e.g., Adams et al., 2011).

Prerequisites and data• Bioeffectivity of cosmic rays• Occurrence rate of Supernova (SN) bursts• Occurrence rate of large solar flares (LSF)• Comparison of relative contribution of SN

bursts and LSF into near-Earth radiation environment

• Recent data on large solar proton events (SPE)• Probability of extreme SPEs in the past• Cosmic rays and evolution of the biosphere

Radiation impact on the biostructures

Bioeffectivity of CR in Space

Tracks from heavy nuclei on the inside of an Apollo helmet (Comstocket al., 1971): A - a track from a particle entering the helmet; B – endingtrack from a particle that crossed from the opposite side of thehelmet and come to rest.

Light Flashes in the Cosmonaut’s Eyes

Visual picture of the light flashes in the cosmonauts’ eyes that were observed during different space missions of 1969-1999 (Pogorely, 2001). Correlation with the passages of CR nuclei. Project ALTEA onboard ISS (Avdeyev et al., 2002).

Metachromasy and neutrons

• Results of the one-way ANOVA of statistical dependence of the metachromasy index for volutin granules in yeast cells, on the intensity of cosmic rays (neutron monitor data, arbitrary units). On the abscissa axis is an index of metachromasy. On the ordinate axis are the mean values of cosmic ray intensity (in counts). The 95% confidence intervals are marked (Gromozova et al., 2010).

Cell cultures and neutrons

• Dynamics of the polynuclei index PCN (relative units by ordinate axis) for cell crops in lines L, CHO, and FHM in October 1989. At the abscissa axis a time is given (in hours) from the beginning of the experiment (22:30 UT of 15 October). Figures at the curves are the moments of fixation (in hours) of laboratory preparations corresponding to increasing of PCN index Belisheva et al., 2006)

Past flares: Nitrate signals

Nitrate concentrations in ice core samples taken in Antarctica (Figure courtesy ofG.A.M. Dreschhoff and E.J. Zeller). 24 September 1909 - observed flare; 7-8 July 1928Major geomagnetic disturbance; 25 July 1946 – white-light flare and GLE04; the peaks in1959 and 1972 coincides with large solar proton fluences (Shea and Smart, 1996).

Nitrate trace of Flare_1859In early September in 1859, telegraph wires suddenly shorted out in the United States and Europe, igniting widespread fires. Colorful aurora, normally visible only in polar regions, were seen as far south as Rome and Hawaii. The event was three times more powerful than the strongest space storm in modern memory, one that cut power to an entire Canadian province in 1989.

Nitrate data by G.E. Kocharov (Soros Journal, 1999)

White light solar flare of 1 September 1859: Carrington, R. C.: 1860, Monthly Notices Royal Astron. Soc. 20, 13; Hodgson, R.: 1860, Monthly Notices Royal Astron. 20, 15. A new account of the 1859 event, from research led by Bruce Tsurutani of NASA's Jet Propulsion Laboratory, details the most powerful onslaught of solar energy in recorded history. The Great Storm: Solar Tempest of 1859 Revealed at SPACE.com

Largest fluences • Largest historical event of 1859: • Φ(≥30 MeV) = 1.88×10^10 cm^(-2) • List of the largest SEP events (1561-1950):

7.1×10^9 (1605); 8.0×10^9 (1619); 6.1×10^9 (1637); 7.4×10^9 (1719); 6.3×10^9 (1727); 6.4×10^9 (1813); 9.3×10^9 (1851); 1.88×10^10 (1859); 7.0×10^9 (1864);7.7×10^9 (1894); 1.11×10^10 (1896) – in total 11 events above Φ(≥30 MeV) = 6×10^9 (all from Greenland ice core).

• McCracken, K.G., Dreschhoff, G.A.M., Zeller, E.J., Smart, D.F., and Shea, M.A., 2001. Solar cosmic ray events for the period 1561-1994. 1. Identification in polar ice, 1561-1950. J. Geophys. Res. 106, No.A10, 21585-21598.

Nitrate concentration in the South Pole core representing ~1200 years (a), and the time equivalent upper part of the Vostok core (b). Historical SNe are indicated for the respective nitrate anomalies. Minimum errors (~10 years for South Pole record; ~30 years for Vostok record) are indicated by error bars (Dreschhoff and Laird, 2006).

SN explosions in Galaxy (the past 1000 y)

Supernova YearDistance,

pcCR energy,

erg

Supernova 1006    

Taurus - А

(Crab nebula) 1054 1100 ~ 5·10 48

Supernova 1181    

Tycho Brage 1572 360 ~ 3·10 46

Kepler 1604 1000 ~ 6·10 46

Cassiopeya - А ~1750 3400 ~ 7·10 49

SN 1987A: Outside Milky Way • SN 1987A was a SN in the outskirts of the Tarantula

Nebula in the Large Magellanic Cloud, a nearby dwarf galaxy. It occurred approximately 51.4 kps from Earth, approximately 168,000 lys, close enough that it was visible to the naked eye. It could be seen from the Southern Hemisphere. It was the closest observed SN since SN 1604, which occurred in the Milky Way itself.

• The light from the new SN reached Earth on February 23, 1987. As it was the first SN discovered in 1987, it was labeled “1987A”. Its brightness peaked in May with an apparent magnitude of about 3 and slowly declined in the following months. It was the first opportunity for modern astronomers to see a SN up close and observations have provided much insight into core-collapse SNe.

• P.S. Last SN in our Galaxy (Cassiopeya - А) has flashed out in 1750. For the past 250 years we should observe ~ 8 SN bursts.

Cosmic rays near the Earth’s orbit from SN bursts and solar flares

Integral occurrence rate ofSCR events at givenenergy density at theEarth’s orbit (top plots).Estimates of ionizationcontribution from SNgamma-flash (bottom plots)at the distance of 10 parsecfrom the Earth (flash) andfrom protons for theperiods of Earth’s stay in SN remnant during 3 years(3 yr) and during all thetime (all time). Wdowczyk and Wolfendale,1977.

Ionization effects from energetic particles (GCR and SCR) and electromagnetic emissions (X- and gamma rays from SNe).

SCR flux and fluence

Integral proton fluences at the Earth’s orbit (left part) and intensity-time profiles of proton fluxes at Ep > 100 MeV for the largest SPEs registered in 1956-2005 [Mewaldt et al., 2007].

Solar Cosmic Rays: Upper Limit Spectrum

A rounding curve 15 corresponds to the hypothetical Upper Limit Spectrum (ULS) for solar cosmic rays (SCR), or solar energetic particles - SEPs (Miroshnichenko, 2003). Integral spectrum for galactic cosmic rays above 10^9 eV is also shown (dotted line). Maximum energy for energetic solar particles Е ≥ 100 GeV?

The integral energy spectra for the largest proton events observed near the Earth in 1942-2000.

Energy spectrum of SEP fluences

• Differential energy spectrum of the fluences for Carrington event (solid line), with expected maximum and minimum deviations (dashed lines). Also are shown the fluence spectra for large proton events in February 1956, November 1960 and August 1972 (Wilson et al., 1999).

1E-1 1E+0 1E+1 1E+2 1E+3 1E+4 1E+5MeV

1E-41E-31E-21E-1

1E+01E+11E+21E+31E+41E+51E+61E+71E+81E+9

1E+101E+111E+12

Flu

ence

#/c

m**

2

February 1956

Novem ber 1960

August 1972

Carrington fluence

New SEP fluence data

• Distribution function of SEP events on the fluences Φ(≥30 MeV) by measurements onboard the satellites IMP-8 and GOES in the solar cycles 21-23 (red points) and by Greenland ice core data (blue points) for the pre-space era. The probabilities of 15 November 1960 and 4 August 1972 events are also shown (green points). Solid line marks an approximation (3), with corresponding root mean square deviations (dashed lines). 1E+6 1E+7 1E+8 1E+9 1E+10 1E+11

Fluence (E>30 MeV) #/cm **2

1E-7

1E-6

1E-5

1E-4

1E-3

1E-2

1E-1

1E+0

1E+1

Pro

bab

ility

21-23 SA cycle events

19-23 SA cycle Nov. 1960 and Aug 1972

Greenland ice events

Integral energy spectra• Integral energy

spectrum of peak proton fluxes for the Carrington event on average (blue line with the stars with dashed lines for the root-mean-square deviations).

• Red line (points) – Upper Limit Spectrum for SCR (ULS) (Miroshnichenko, 1994, 1996); green triangles – ULS, corrected in the present work. 1E-1 1E+0 1E+1 1E+2 1E+3 1E+4 1E+5

MeV

1E-101E-91E-81E-71E-61E-51E-41E-31E-21E-1

1E+01E+11E+21E+31E+41E+51E+61E+7

Pea

k fl

ux

#/(c

m**

2*s*

sr)

A

B

Model dependencies• In the context of this study, also deserve serious attention the

estimates of the proton fluences at some other energies (besides 30 MeV), especially, for the understanding of flare (proton) activity of the Sun in the remote past. Many years ago, Wdowczyk and Wolfendale (1977) addressed the question on the long-term frequency of large solar energy releases and their possible effects, compared with other catastrophic events. The main body of their evidence appears still valid, although some details have changed. The very flat integral power-law fits (logarithmic slope around -0.5) suggest that several dramatic solar energy releases should be expected in geologically short times, if the trend continues. Extrapolating their highest energies (>60 MeV) fit to long time scales, Kiraly and Wolfendale (1999) obtained some another estimates. It turns out that while the highest fluence measured up to now (in about 30 years) was 310^9 cm^-2, one would expect in 1 My a few events above 10^12 cm^-2, and in 100 My a few above 10^13 cm^-2. This is far less than one would expect from flat slopes found by Wdowczyk and Wolfendale (1977), but still about two orders of magnitude higher than it follows from our estimates.

Fluence extrapolation to the past• In fact, according to modern data on proton fluences at the energy ≥30

MeV, for the period from 1973 up to 2008 there were registered 205 events with the fluence ≥10^6 cm^-2 (Nymmik, 2011c). If solar activity remains at modern (present) level, it means that for 1 My and 100 My, respectively, we may expect for 6×10^6 and 6×10^8 of such events, and the probabilities of their realization would be ~ 1.7×10^-7 and ~1.7×10^-9, respectively. According to our estimates (Fig.9), for such long periods the events may appear with the fluences up to 6×10^10 and 10^11 сm^(-2), respectively, that is for 1.5-2 orders of magnitude lesser that the estimates by Kiraly and Wolfendale (1999).

• Difference in the energies of protons (30 and 60 MeV) makes this discrepancy even much more. The cause of this discrepancy is rather simple. As it was repeatedly noted (Nymmik 2006, 2007a,b, 2011), lognormal distribution function of SEP events (Feynman et al., 1993) that was applied by Kiraly and Wolfendale (1999), by no means does reflect a physical essence of SEP event distribution in the range of large fluences. Parameters of the model by Feynman et al. (1993) are determined mainly by subjective (random) magnitudes of the registration thresholds and selection of small SEP events; therefore, they can not serve for the extrapolation of the data into the range of extremely large events.

Probabilities of extreme events • Distribution function

of SEP events on the fluences of Φ(≥30 MeV): points with the statistical errors – measurement data onboard the spacecraft IMP-8 and GOES; blue diamonds – estimates by the data from Greenland ice core; solid red line – distribution function (3); triangles – our estimates of Φ(≥30 MeV) by Kiraly and Wolfendale (1999) data; segment АВ = 7.2.

1E+6 1E+7 1E+8 1E+9 1E+101E+111E+121E+13Fluence #/cm**2

1E-11

1E-10

1E-9

1E-8

1E-7

1E-6

1E-5

1E-4

1E-3

1E-2

1E-1

1E+0

1E+1

Pro

bab

ility

A B

Conclusions

• Thus, we obtained a number of physical and methodical limitations that are important for the estimations and predictions of radiation hazardous SCR fluxes. The technique developed on the base of new ideas on the particle fluxes and their intrinsic features enables us also to consider by new the problem of “limit” values that characterize the SEP fluxes at different energies in the present epoch. At the same time, we do not pretend to give some final values of our quantitative estimates that can be specified when some new observational data come.

Acknowledgements • This work is partially supported by RAS_28 Program of

Fundamental Research “Problems of the life origin and formation of the biosphere” (Russian Academy of Sciences).

• В.Н. Обридко, Л.И. Мирошниченко, М.В. Рагульская, О.В. Хабарова, E.Г. Храмова, М.М. Кацова, М.А. Лившиц. Космические факторы эволюции биосферы: Новые направления исследований. - Проблемы эволюции биосферы. Серия «Гео-биологические системы в прошлом». М.: Палеонтологический Институт (ПИН) РАН, 2013. С. 66–94 (Труды конференции, посвящённой памяти академика Г.А. Заварзина, 21-22 марта 2012 г.).

• http://www.paleo.ru/institute/files/biosphere.pdf

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Energetic Particle Models. Proc. 32nd Int. Cosmic Ray Conf., China, Beijing, 10, 19-22.

• Crosby, N.B., 2009. Solar extreme events 2005–2006: Effects on near-Earth space systems and interplanetary systems. Adv. Space Res. 43, 559–564.

• Ellison, D.C., and Ramaty, R., 1985. Shock acceleration of electrons and ions in solar flares. Astrophys. J. 298, 400-408.

• Feynman, J., Spitale G., Wang, J., 1993. Interplanetary Proton fluence model: JPL-91. J. Geophys. Res., 98, 13281-13294.

• McCracken, K.G., Dreschhoff, G.A.M., Zeller, E.J., Smart, D.F., and Shea, M.A., 2001. Solar cosmic ray events for the period 1561-1994. 1. Identification in polar ice, 1561-1950. J. Geophys. Res. 106, No.A10, 21585-21598.

• Miroshnichenko, L.I., 1977. Dynamic model of spectrum formation for solar cosmic rays. Proc. 15th Int. Cosmic Ray Conf., Plovdiv, Bulgaria, v.5, p.214-219.

• Miroshnichenko, L.I., 1983. On estimations of energetics of solar cosmic rays. In: «Problems of solar flare physics (Editor-in-Chief A.A. Korchak). Moscow, IZMIRAN, p.120-125.

• Miroshnichenko, L.I., 1990. Dynamics and prognosis of radiation characteristics of solar cosmic rays. Dissertation of Full Doctor’s Degree in Physics and Mathematics. Moscow, IZMIRAN, 326 pp.

Important references-2• Miroshnichenko, L.I., 1994. On the ultimate capabilities of particle

accelerators on the Sun. Geomagnetism and Aeronomy. 34(4), 29-37.• Miroshnichenko, L.I., 1996. Empirical model for the upper limit spectrum

for solar cosmic rays at the Earth’s orbit. Radiation Measurements. 26(3), 421-425.

• Miroshnichenko L.I. Radiation Hazard in Space. Kluwer Academic Publishers, 2003, 238 pp.

• Nymmik, R.A., 2007c. Extremely large solar high-energy Particle events: occurrence probability and characteristics. Adv. Space Res. 40(3), 326-330.

• Townsend, L.W., Zapp, E.N., Stephens, D.L. Jr., and Hoff, J.L., 2003. Carrington flare of 1859 as a prototypical worst-case solar energetic particle event. IEEE Transact. Nucl. Sci. 50(6), 2307-2309.

• Townsend, L.W., Stephens D.L. Jr., Hoff, J.L., Zapp, E.N., Moussa, H.M., Miller, T.M., Campbell, C.E., and Nichols, T.F., 2006. The Carrington event: Possible doses to crews in space from a comparable event. Adv. Space Res., 38, 226–231.

• Wdowczyk, J., and Wolfendale, A.W., 1977. Cosmic rays and ancient catastrophes. Nature, 268(5620), 510-512.

• Wilson, J.W., Cucinotta, F.A., Shinn, J.L., Simonsen, L.C., Dubbed, R.R., Jordan, W.R., Jones, T.D., Chang, C.K., and Kim, M.Y., 1999. Shielding from solar particle event exposures in deep space. Radiation Measurements 30(3), 361–382.

Contact information• Dr. LEONTY I. MIROSHNICHENKO• Sector of Helio-Ecological Relations• Department of Physics of Solar-

Terrestrial Relations, N.V. Pushkov Institute IZMIRAN, Troitsk, Moscow Region, PB 142190, RUSSIA 

• Phone: 007(495)851-02-82; 007(495)939-58-68; 007(495)851-23-61

• Fax: 007(495)851-01-24 • E-mail: leonty@izmiran.ru