Solar Cosmic Rays: 70 Years of Ground-Based Observations

© 2012 Leonty I. MiroshnichenkoN.V. Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation (IZMIRAN), Russian Academy of Sciences (RAS), Troitsk, RUSSIA

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

8th Winter Workshop and School on Astroparticle Physics (WAPP)-2013, Darjeeling, India,17-28 December 2013

Artist illustration of a coronal mass ejection. Image credit: NASA/MSFC

Fundamental Problem:

Flare-CME, Physical and/or

Topological

Links

“Dedications”• 154 años de la observación de una ráfaga solar por

Richard Christopher Carrington (1 September 1859).• 81 years of the first laboratory accelerator (1932).• 80 years of acceleration theory: Betatron mechanism in

space (Swann, 1933). • 71 GLE events since 28 February 1942: Surface

detectors of cosmic rays – Ground Level Events (Enhancements) of Solar Cosmic Rays (SCR). Discovery of particle acceleration at the Sun (1942).

• 71 years of solar radio astronomy (the end of February 1942).

• 41 years of solar gamma-astronomy (August 1972), OSO-7 and Prognoz.

• Et cetera…

Particle Acceleration in Space: Ideas, Theories and Models

• 1933 - Betatron mechanism (Swann)• 1949 - Stochastic mechanism (Fermi I, Fermi II) • 1953 – Theory of magnetic reconnection (Dungey)• 1966 - Acceleration by DC electric field at dynamical

dissipation of magnetic field (Syrovatsky) • 1977 - «regular» mechanism, or “diffusive shock

acceleration” (Krymsky, 1977, 1981; Axford et al., 1977; Bell, 1978; Blandford and Ostriker,1978).

• 1985 - Acceleration at plane shock wave in the solar corona (Ellison & Ramaty).

• 2000 - Acceleration at plane shock wave in the interplanetary medium (Zank et al.).

• 2003 – Entire scenario of acceleration of SCR at spheric shock wave near the Sun (Berezhko et al.).

Particle Acceleration at/near the Sun:Recent Development of Models

• 2005 – 2011 - Tylka et al. (2005), Kahler et al. (2011): High Fe/O ratio is a signature of a shock that is quasi-perpendicular while near the Sun, preferentially drawing its seed population from flare remnants. Because quasi-perpendicular shocks require a higher injection energy, they generally draw from a smaller seed population than quasi-parallel shocks. As a result, events with quasi-perpendicular near-Sun shocks will generally have smaller proton fluences, at least at the higher energies produced primarily while the shock is near the Sun.

• 2011 – Somov et al.: Reconnecting current sheet (RCS) with a 3-component MF and electric field. Numerical solution of relativistic equation of motion. Acceleration to relativistic energies for very short times: ~2×10^(-7)÷10^(-3) s for electrons and ~10^(-4)÷2×10^(-2) s for protons.

• PS: Multiple Acceleration Processes at the Sun…

February 1942: Two important stakes in the study of the Sun

1. First evidence of particle acceleration in space. Arrival of relativistic particles from the Sun (≥ 500 MeV for protons) in close link with solar flares.

2. Beginning of the solar radio astronomy (28 February 1942).

3. Discovery of shock waves in space (discovery of the heliosphere).

Simpson, J.A.: 1990, Astrophysical phenomena discovered by cosmic rays and solar flare Ground Level Events: The early years, Proc. 21st Int. Cosmic Ray Conf., Invited Papers, Highlight Papers, Miscellaneous, Adelaide, Australia, 12, 187-195.

Spaceship “Earth”

First three SCR (GLE) events

Ionization Chamber in Cheltenham,USA, geomagnetic latitude of 48° А – onset moments of radio fadeout;В – onset moments of geomagnetic storms (sudden commencement); С– onset moment of solar flare of 25July 1946. These observations«…suggest the rather strikingpossibility that the three unusualincreases in cosmic ray intensitymay have been caused by chargedparticles actually being emitted bythe Sun with sufficient energy toreach the Earth at geomagneticlatitude of 48° but not at theequator» (Forbush, 1946). International numeration of GLEs –from GLE01 (28 February 1942) toGLE71 (17 May 2012).

-10

40

90

140

190

240

17 18 19 20 21 22 23 24

Time of Day, 22 October 1989 (hr)

% In

crea

se

McMurdo

Thule

South Pole

Worldwide Network of CR stations: GLE of 22 October 1989:

Two relativistic components?

GLE of 20 January 2005: Effect on non-standard detector “Carpet” (BNO)

GLE71 (17 May 2012): What’s next?

• Two neutron monitors in the northern hemisphere: Apatity (Kola Peninsula), Barentsburg (Spitzbergen)

GLE 71: 17 May 2012, the first GLE in 24th solar cycle

Klein, Bütikofer, 2012, at http://www.nmdb.eu/?q=node/480. Highest signal at South Pole, both detectors. No signal observed at > 3 GV cut-off.

GLE ranks Таблица 2. Амплитуда событий GLE (in %) в солнечных циклах 17-23.

Примечания: N.O. – не было наблюдений. После вспышки 20 января 2005 г. на стандартных мюонных телескопах, по-видимому, не было зафиксировано никакого возрастания (это свидетельствует о мягком спектре СКЛ), хотя некоторые не-стандартные мюонные детекторы зарегистрировали статистически значимые эффекты в мюонной компоненте.

Rank Date/Detector Ion Chamber MuonTelescope Neutron Monitor 1 23 Feb 1956 300 280 4554 (15-min) 2 20 Jan 2005 N.O. No increase? 4527.4 (1-min) 3 19 Nov 1949 41 70 563 4 29 Sep 1989 N.O. 41 373 5 25 Jul 1946 20 N.O. N.O. 6 28 Feb 1942 15 N.O. N.O. 7 07 Mar 1942 14 N.O. N.O.

Rank Date IC/Station МТ/Station NM/Station Duggal

1 23.02.1956 300/Moscow/15 280/London/15 4554/Leeds/15 9000

2 20.01.2005 No Observation 13/GRAND, 1 4200/Terre Adélie, 1

-

3 19.11.1949 40/Cheltenham/15 70/Ottawa, 15 563/Manchester, 60 2000

4 25.07.1946 22/Cheltenham/15 13/Manchester, 60

No Observation 1100

5 07.03.1942 15/Cheltenham, 15 27/Friedrichs-hafen, 60

No Observation 750

6 28.02.1942 15.5/Godhavn, 15 00/Friedrichs-hafen, 60

No Observation 600

7 29.09.1989 No Observation 41/Inuvik, 5 377/Inuvik, 5 -

Magnitude of GLEs in solar cycles 17-23 (in %) over the pre-event Galactic Cosmic Ray background at sea

level (1 July 2013)

GLEs 1942-2006: Heliolongitude distribution

• Black circles – Shea & Smart, 1993 (48 GLEs of 1956-1991).

• Open circles – my addition of 2011 (70 GLEs of 1942-2006).

• Heliolongitude distribution is asymmetric relative to the Sun-Earth line.

• IMF as a regulator of the GLE registration rate.

Yearly numbers of the >10 MeV proton events at intensity threshold > 1

pfu (dashed line) in comparison with the level of solar activity W (solid line), for the period of 1955-1996 (Miroshnichenko, 2001).

SPE numbers demonstrate two-peak structure (Gnevyshev Gap, or GG effect). Automatically, this set also included all GLEs for solar activity cycles 19-22

Integral Energy Spectrum

• Integral energy spectra of solar protons for some large GLEs for the entire period of observations (1942-2006). Spectra for the events of solar cycle 23 have been summarized by [Wang, 2009]. Spectrum for the GLE42 (29 September 1989) is completed by a new estimate of primary proton intensity at the energy of Ep 500 ГэВ («Baksan effect», mark ♥ at the left panel, right lower corner). Curve 15 is an Upper Limit Spectrum (ULS) for SCR.

SCR Flux and Fluence

Integral proton fluences at the Earth’s orbit (left panel) and time profiles of the proton fluxes with energy Ep > 100 MeV (right panel) for the most powerful Solar Proton Events (SPEs) for the period of 1956-2005 [Mewaldt et al., 2007].

Mechanisms and Models of Acceleration

• Acceleration in the CS region at the Sun• Stochastic acceleration in the solar

atmosphere • Acceleration at shock waves in the solar

corona and interplanetary medium • Two levels in the acceleration problem: • 1. «Local» kinetic modeling («micro-level») • 2. «Global» MHD modeling («macro-level»). • Two relativistic components of SCR: New

concept of GLE?

Flares/СМЕ: Two classes ofsolar flares(impulsive andGradual ones) - two differentscenarios ofacceleration andrelease of solarcosmic rays(SCR)? Reames, 1999; Kallenrode, 2002.

Measured, derived and calculated proton energy spectra: IMP 8, GOES 7, and NM

data (Lovell et al. 1998, shaded area – Delayed Component

only). Diffusive Shock Acceleration:

Berezhko & Taneev, 2003

β - Alfvén wave spectral index.

D(E) ∞ E^(-γ)exp[(-E/Ec)^α] e-folding energy: Ec ≥ 300 MeV?

Spectrum of the GLE of 29 September 1989: Theory

Peculiarities in GLE occurrence rate • We may suggest with a great confidence that during the first years of GLE

observations of SCR (i.e., before the organization of the worldwide net of CR stations) some small GLEs have not been registered. Therefore, occurrence rate of GLE registration, the most likely, was underestimated, because of some portion of the events on technical and methodological reasons was certainly (deliberately) omitted. Judging from average GLE rate of η~1.0 per year, a number of omitted events for the period of 1942-1956 could be considerable. In fact, from 14 expected «averaged statistical» events, before 1956 only 4 GLEs have been recorded [Miroshnichenko and Perez-Peraza, 2008]. As a result, complete time series of 71 GLEs turned out to be impoverished by weak (small) GLEs.

• On the other hand, after the GLE70 (13 December 2006, solar cycle 23) and up to GLE71 of 17 May 2012 г. (current cycle 24), i.e. more than 5 years, we observed no GLE. Similar peculiarity in the GLE occurrence rate manifested itself also in the two previous solar cycles. In particular, between GLE39 (16 February 1984) and GLE40 (25 July 1989) more than 5 years passed, and between GLE54 (2 November 1992) and GLE55 (6 November 1997) – nearly 5 years.

• Although, strongly delayed and extended minimum of solar cycle 23 has finally ended in December 2008, the development of solar cycle 24 goes very slowly (inertly). In fact, sunspot formation, flare and «proton» activity of the Sun, in general, are at rather low level.

• In spite of some restrictions in the model (analogue) PWM series of GLE occurrence rate mentioned by (Miroshnichenko et al., 2012), some regularities in this series, nevertheless, may be found.

Cycles 23 and 24 • Very weak cycle 24

PWM series for GLE occurrence rate

GLEs and GMF of the Sun•

PWM series for the parameter η contains statistically significant oscillation with a period of ~11 years. Moreover, these oscillations are in a certain coherence with time series of some other indexes (parameters) of the solar photosphere (for example, with a sunspot number SS) and corona (for example, with the periodicities in the behaviour of coronal index CI). Wavelet diagrams of coherence show that PWM series of GLE events are in the same phase with time series for solar indexes SS and CI during entire period under study (1942-2006 гг.). In spite of limitations of GLE statistics and restrictions posed by the method of wavelet analysis, obtained results may be important for understanding of periodic phenomena in the solar dynamo, solar atmosphere, interplanetary medium and cosmic rays.

• Certain tendency of GLE to concentrate mainly on ascending and/or descending stages of solar activity (SA) cycles seems to be due to spatial-temporal structure of the Global Magnetic Field (GMF) of the Sun. As known, just near the maximums of SA, a reconstruction (sign inversion) of GMS takes place. To analyze this tendency of GLE, Nagashima et al. (1991] used the data of MTs and NMs for 43 GLEs registered in the period of 1942-1990. It was shown that the flares that caused GLEs, in essence, are forbidden during the transition stage of solar cycle, when sign inversion of the GMF takes place. A GLE absence exactly at the moment of solar maximum (at least, for the cycles 17-21) the authors [Nagashima et al., 1991] explained not by the suppression of proton production by the Sun because of strong magnetic fields, but a deterioration of the efficiency of proton acceleration during the structural re-arrangement of the fields in the transitional period. Но уже в 22-ом цикле СА частота событий GLE резко возросла, а их число оказалось аномально большим (15). При этом 7 из них произошли в течение 5-ти месяцев по достижении максимума по параметру SS (июль 1989 г.), а остальные 8 наблюдались фактически в период изменения знака ГМП (1991-1992 гг.). Очевидно, что требуются дополнительные исследования этой проблемы.

Prospects?• It is quite obviously that before making certain conclusions, we

are needed in additional investigations. In particular, in order to separate the effects of SCR acceleration and their release from the solar atmosphere, it is necessary to study the structure and dynamics of large-scale magnetic fields in the solar corona for some large individual events of the 29 September 1989 kind (GLE42) [Miroshnichenko et al., 2000].

• Of particular interest is a dynamics of the solar magnetic field during 1989 which was notable for the series of large SPEs (GLEs). The main peculiarity of that period is not only due to disturbances in solar wind parameters (although they did also occur), but due to unexpected large GLE of September 29, 1989. This extraordinary event was preceded by an anomalously fast change in the global magnetic structure in the corona. During less than two solar rotations (1818-1819) the position of the dipole pole displaced in the heliolongitude as much as 180 degrees. Such a kind of fast global changes are unique ones for the period from 1976 to 1993 [Zherebtsov et al., JGR, 1997].

Nearest Future?

• 2012 was a significant year from an historical and astronomical perspective. According to astronomers the Poles of our Sun will reverse towards the end of 2012.  Under the right conditions this could have a serious knock-on effect on Earth.  A sudden twist in the orientation of the Sun’s poles could also reverse the Earth’s poles as well. “For we know in part and we prophesy in part…” (Apostle Paul, 1 Corinthians 13:9)

SCR, geophysics and heliosphere: Fundamental and applied aspects

SCR as one of effective modern toolsfor the study of the Sun andHeliospheric properties

Ionization in the Earth’s atmosphere during the three GLEs: Contribution of the protons with energies up to 500

MeV [Quack et al., 2001]

Production of cosmogenic isotopes of beryllium 7Be, chlorine 36Cl and beryllium 10Be (calculations) during a series of large solar proton events in October-November 2003 [Webber et al., 2007].

Reviews and monographs on SCR• Elliot (1952); Dorman (1958); Carmichael (1962); Dorman

& Miroshnichenko (1968); Sakurai (1974); Pomerantz and Duggal (1974); Duggal (1979); Dorman & Venkatesan (1993); Reames (1999); Ryan et al. (2000). In the framework of more general problem of cosmic ray (CR) variations, the SCR problem was considered in detail in the two monographs by Dorman (1957, 1963).

• Different methodical, experimental, and general physical aspects of SCR investigation, specific features of interaction between SCRs and the solar atmosphere, SCR geophysical effects, the possible SCR contribution to the problem of solar-terrestrial relations, and certain present day applied aspects were subsequently described in the reviews and monographs by Miroshnichenko (2001, 2003, 2011); Miroshnichenko and Perez-Peraza (2008). Dorman (2004, 2006, 2009, 2010); Miroshnichenko et al. (2012, 2013).

“PIENSE en GRANDE”: CONTINUAMOS…

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)851-09-26; 007(495)851-23-61

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

Flare Forecast: «Formula for Success»

Shea and Smart, 1993: «Formula for Success».

But “The Sun does not

cooperate with us…”

P.S. Our Youth: Heroes and Disciples

Jorge A. Perez-Peraza and Igor Y. Libin. Highlights in Helioclimatology. Cosmophysical Influences on Climate and Hurricanes. Elsevier, 2012