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Correlation study of atmospheric weather and cosmic ray flux variation

Correlation study of atmospheric weather and cosmic ray flux variation. Kanishka Dayananda Georgia State University. Outline. Introduction Cosmic ray detectors maintained by Georgia State University Meteorological and solar modulation effects on the variation of cosmic ray flux Summary.

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Correlation study of atmospheric weather and cosmic ray flux variation

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  1. Correlation study of atmospheric weatherand cosmic ray flux variation Kanishka Dayananda Georgia State University SESAPS11

  2. Outline • Introduction • Cosmic ray detectors maintained by Georgia State University • Meteorological and solar modulation effects on the variation of cosmic ray flux • Summary SESAPS11

  3. Introduction • There is at present a great debate about the causes of the changing climate of the Earth. • The studies by Svensmark, show that there is a strong link between cosmic rays and low cloud coverage [1]. Very recently, Lu reported that there is a correlation between cosmic rays and ozone depletion over Antarctica [2]. • At Georgia State University we are working on a long-term measurement of secondary cosmic ray flux distribution and are focusing on studying the correlations among variations of cosmic ray flux and atmospheric/space weather. SESAPS11

  4. Pot detector - liquid scintillator 2paddle detector QNet 2paddle detector Lanzhou -China HLCO-BaF2 scintillator QNet 2paddle detector eMorpho 2paddle detector Our cosmic ray detectors http://phynp6.phy-astr.gsu.edu/~kanishka/OnLineMonitor/index.htm SESAPS11

  5. Factors that influence the variation of cosmic ray flux • Meteorological effects • atmospheric pressure, temperature, cloud cover etc… • Solar modulation effects • interplanetary magnetic field, solar wind speed etc… • The barometric effect is the major influencing factor on the secondary cosmic ray particles[3]. • Therefore it is necessary to eliminate the barometric effect first to unfold the solar modulation of the cosmic ray flux. SESAPS11

  6. Barometric effects on secondary cosmic ray flux Pot – counts 11/3010 – 01/27/10 Correlation coefficient ( r ) = -0.64 SESAPS11

  7. Variation of solar parameters in year 2010 http://omniweb.gsfc.nasa.gov/form/dx1.html Correction of counts for pressure Reference [4] b = barometric coefficient I = counts P = pressure I = corrected counts Io = measured counts P0 = mean pressure SESAPS11

  8. Uncorrected counts 11/30/10 – 01/27/10 Correlation coefficient ( r ) = -0.64 Corrected counts 11/30/10 – 01/27/10 Correlation coefficient ( r ) = -0.02 Correction of counts for pressure cont… SESAPS11

  9. Seasonal variation in the pot detector counts SESAPS11

  10. Daily % variation of counts & weather parameters SESAPS11

  11. Forbush decrease events detected by pot detector SESAPS11

  12. Aug 05 2011 Sep 26 2011 Forbush decrease events SESAPS11

  13. Summary • Results confirm that there is an anti-correlation between secondary cosmic ray flux and atm pressure. • Results also confirm that the anti-correlation between secondary cosmic ray flux and atm temperature is due to expansion of the height of the atm pressure levels. • Since our pot detector is sensitive for both charged particles and neutrons, we are currently working on studying the correlation between variation of neutrons and cloud coverage. • These results can be used to unfold the solar modulation effects on the cosmic ray flux. • Our long-term goal is to build a world wide cosmic ray detector network and predict the variation of atmospheric and space weather using the cosmic ray flux variation. SESAPS11

  14. References • N.D. March and H. Svensmark, Low Cloud Properties Influenced by Cosmic Rays, Phys. Rev. Lett. 85, 23 (2000). • Q.-B. Lu, Correlation between Cosmic Rays and Ozone Depletion, Phys. Rev.Lett. 102, 118501 (2009). • A. Chilingarian, T. Karapetyan, Calculation of the barometric coefficients at the start of the 24th solar activity cycle for particle detectors of Aragats Space Environmental Center, Advances in Space Research 47 (2011) 1140–1146. • L.I. Dorman, Cosmic Rays, Variations and Space Exploration. Amsterdam, North-Holland, 1974. • S. Tilav, P. Desiati, T. Kumwabara, D. Rocco, F. Rothmaier, M. Simmons, and H. Wissing, “Atmospheric Variations as Observed by IceCude”, Proceedings of the 31st ICRC, 2009. • M. Bertaina, L. Briatore, A. Longhetto, G. Navarra, The atmospheric moun flux in correlation with temperature variations in the low stratosphere(50-200mb), Proceedings of the 30th International Cosmic Ray Conferrencs. SESAPS11

  15. Thank you SESAPS11

  16. Backup slides SESAPS11

  17. % Variation of atm heights of different atm pressure levels SESAPS11

  18. % Variation of atm temperatures of different pressure levels SESAPS11

  19. Correlation of temperature and counts in different atm pressure regions SESAPS11

  20. Correlation of temperature and counts in different atm pressure regions cont… SESAPS11

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