Skip to main content Accessibility help
×
×
Home

The Cosmic Ray Increases At 35 and 60 Kyr BP

  • V Florinski (a1), W I Axford (a1) and G P Zank (a1)

Abstract

Concentrations of 10Be in ice cores and marine sediments exhibit 2 peaks with significant enhancements at 35,000 and 60,000 BP. This radioisotope is produced in the upper atmosphere by spallation of cosmic-ray protons and secondary neutrons on atmospheric nitrogen and oxygen. Previously suggested explanations for the increases include geomagnetic field reversals, a decrease in solar activity, and a supernova explosion. We propose an alternative explanation which involves a change in the galactic environment of the solar system. The structure of the heliosphere is investigated for a period when the Sun enters a cold, dense, unmagnetized interstellar cloud. Under these conditions, the heliosphere contracts to 25% its present size, significantly affecting galactic cosmic ray modulation and increasing anomalous cosmic ray fluxes. A tenfold increase in anomalous cosmic ray flux and a twofold increase in galactic cosmic ray intensity at Earth are possible in this high-density case if heliosheath modulation is reduced. We show that this increase in galactic cosmic ray intensity could be responsible for the peaks in 10Be records.

    • Send article to Kindle

      To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.

      Note you can select to send to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

      Find out more about the Kindle Personal Document Service.

      The Cosmic Ray Increases At 35 and 60 Kyr BP
      Available formats
      ×

      Send article to Dropbox

      To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Dropbox.

      The Cosmic Ray Increases At 35 and 60 Kyr BP
      Available formats
      ×

      Send article to Google Drive

      To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Google Drive.

      The Cosmic Ray Increases At 35 and 60 Kyr BP
      Available formats
      ×

Copyright

Corresponding author

Corresponding author. Email: vflorins@citrus.ucr.edu.

References

Hide All
Axford, WI. 1981. Acceleration of cosmic rays by shock waves. Proceedings of the 17th International Cosmic Ray Conference (Paris) 12:155204.
Baranov, VB, Malama, YG. 1993. Model of the solar wind interaction with the local interstellar medium: numerical solution of self-consistent problem. Journal of Geophysical Research 98:15,15763.
Beer, J. 2000. Long-term indirect indices of solar variability. Space Science Reviews 94:5366.
Beer, J, Blinov, A, Bonani, G, Finkel, RC, Hofmann, HJ, Lehmann, B, Oeschger, H, Sigg, A, Schwander, J, Staffelback, T, Stauffer, B, Suter, M, Wölfli, W. 1990. Use of 10Be in polar ice to trace the 11-year cycle of solar activity. Nature 347:164–6.
Brown, L, Stensland, GJ, Klein, J, Middleton, R. 1989. Atmospheric deposition of 7Be and 10Be. Geochimica et Cosmochimica Acta 53:135–42.
Cini Castagnoli, G, Albrecht, A, Beer, J, Bonino, G, Shen, C, Callegari, E, Taricco, C, Dittrich-Hannen, B, Kubik, P, Suter, M, Zhu, GM. 1995. Evidence for enhanced 10Be deposition in Mediterranean sediments 35 kyr BP. Geophysical Research Letters 22:707–10.
Cini Castagnoli, G, Bonino, G, Taricco, C, Lehman, B. 1998. Cosmogenic isotopes and geomagnetic signals in a Mediterranean sea sediment at 35,000 yr BP. Il Nuovo Cimento 21:243–6.
Cummings, AC, Stone, EC, Steenberg, CD. 2002. Composition of anomalous cosmic rays and other heliospheric ions. Astrophysical Journal 578:194210.
Ellis, J, Fields, BD, Schramm, DN. 1996. Geological isotope anomalies as signatures of nearby supernovae. Astrophysical Journal 470:1227–36.
Fahr, HJ, Kausch, T, Scherer, H. 2000. A 5-fluid hydrodynamic approach to model the solar system—interstellar medium interaction. Astronomy and Astrophysics 357:268–82.
Fichtner, H. 2001. Anomalous cosmic rays: messengers from the outer heliosphere. Space Science Reviews 95: 639754.
Florinski, V, Zank, GP, Pogorelov, NV. 2003. Galactic cosmic ray transport in the global heliosphere. Journal of Geophysical Research 108:1228.
Frisch, PC. 2000. The galactic environment of the Sun. Journal of Geophysical Research 105:10,27989.
Graham, I, Ditchburn, R, Barry, B. 2003. Atmospheric deposition of 7Be and 10Be in New Zealand rain (1996–98). Geochimica et Cosmochimica Acta 67: 361–73.
Jokipii, JR, Kota, J, Merenyi, E. 1993. The gradient of galactic cosmic rays at the solar-wind termination shock. Astrophysical Journal 405:782–6.
Kocharov, GE. 1994. On the origin of cosmic rays. Astrophysical Letters and Communications 29:227–32.
Laj, C, Kissel, C, Scao, V, Beer, J, Thomas, DM, Guillou, H, Muscheler, R, Wagner, G. 2002. Geomagnetic intensity and inclination variations at Hawaii for the past 98 kyr from core SOH-4 (Big Island): a new study and a comparison with existing contemporary data. Physics of the Earth and Planetary Interiors 129:205–43.
Lallement, R. 2001. Heliopause and asteropauses. Astrophysics and Space Science 277:205–17.
Lauroesch, JT, Meyer, DM. 1999. Observations of small-scale interstellar structure in dense atomic gas. Astrophysical Journal 519:L181L184.
Masarik, J, Beer, J. 1999. Simulation of particle fluxes and cosmogenic nuclide production in the earth's atmosphere. Journal of Geophysical Research 104:12,099111.
McDonald, FB. 1998. Cosmic-ray modulation in the heliosphere—a phenomenological study. Space Science Reviews 83:3350.
McHargue, LR, Damon, PE, Donahue, DJ. 1995. Enhanced cosmic-ray production of 10Be coincident with Mono Lake and Laschamp geomagnetic excursions. Geophysical Research Letters 22:659722.
McHargue, LR, Donahue, DJ, Damon, PE, Sonett, CP, Biddulph, D, Burr, G. 2000. Geomagnetic modulation of the late Pleistocene cosmic-ray flux as determined by 10Be from Blake Outer Ridge marine sediments. Nuclear Instruments and Methods in Physics Research Section B 172:555–61.
Pauls, HL, Zank, GP, Williams, LL. 1995. Interaction of the solar wind with the local interstellar medium. Journal of Geophysical Research 100:21,595604.
Raisbeck, GM, Yiou, F, Bourles, D, Lorius, C, Jouzel, J, Barkov, NI. 1987. Evidence for two intervals of enhanced 10Be deposition in Antarctic ice during the last glacial period. Nature 326:273–7.
Ramadurai, S. 1995. Very long time variations of the cosmic ray intensity and their origin. Advances in Space Research 15(1):41–8.
Robinson, C, Raisbeck, GM, Yiou, F, Lehman, B, Laj, C. 1995. The relationship between 10Be and geomagnetic field strength records in central North Atlantic sediments during the last 80 ka. Earth and Planetary Science Letters 136:551–7.
Scherer, K, Fichtner, H, Stawicki, O. 2002. Shielded by the wind: the influence of the interstellar medium on the environment of Earth. Journal of Atmospheric and Solar-Terrestrial Physics 64:795804.
Smith, RK, Cox, DP. 2001. Multiple supernova remnant models of the Local Bubble and the soft X-ray background. Astrophysical Journal Supplement Series 134:283309.
Sonett, CP, Morfill, GE, Jokipii, JR. 1987. Interstellar shock waves and 10Be from ice cores. Nature 330: 458–60.
Steenberg, CD, Moraal, H. 1996. An acceleration/modulation model for anomalous cosmic ray hydrogen in the heliosphere. Astrophysical Journal 463:776–83.
Steig, EJ, Polissar, PJ, Stuiver, M, Grootes, PM, Finkel, RC. 1996. Large amplitude solar modulation cycles of 10Be in Antarctica: implications for atmospheric mixing processes and interpretation of the ice core record. Geophysical Research Letters 23:523–6.
Wagner, G, Masarik, J, Beer, J, Baumgartner, S, Imboden, D, Kubik, PW, Synal, H-A, Suter, M. 2000. Reconstruction of the geomagnetic field between 20 and 60 kyr BP from cosmogenic radionuclides in the GRIP ice core. Nuclear Instruments and Methods in Physics Research B 172:597604.
Zank, GP. 1999. Interaction of the solar wind with the local interstellar medium: a theoretical perspective. Space Science Reviews 89:413688.
Zank, GP, Frisch, PC. 1999. Consequences of a change in the galactic environment of the Sun. Astrophysical Journal 518:965–73.
Zank, GP, Matthaeus, WH, Bieber, JW, Moraal, H. 1998. The radial and latitudinal dependence of the cosmic ray diffusion in the heliosphere. Journal of Geophysical Research 103:2085–97.
Zank, GP, Pauls, HL, Williams, LL, Hall, DT. 1996. Interaction of the solar wind with the local interstellar medium: a multifluid approach. Journal of Geophysical Research 101:21,63955.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Radiocarbon
  • ISSN: 0033-8222
  • EISSN: 1945-5755
  • URL: /core/journals/radiocarbon
Please enter your name
Please enter a valid email address
Who would you like to send this to? *
×

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed