Are cosmic rays responsible for climate change?

Transcription

1 Cosmoclimatology Kristina Pistone SIO 209: Cloud Physics 5 June 2009

2 Are cosmic rays responsible for climate change? I call it cosmoclimatology and I suggest that it is already at least as secure, scientifically speaking, as the prevailing paradigm of forcing by variable greenhouse gases. (Svensmark 2007) The idea: variations in solar energy allow more or less cosmic rays to reach the Earth, which ionize the atmosphere, inducing more cloud nucleation than would otherwise occur

3 Are cosmic rays responsible for climate change? Negative ions in the atmosphere attract molecules into small, thermodynamically stable clusters which can then more easily form CCN Evidence suggests that increased solar activity produces a decrease in cosmic ray activity

4 Source Data: ISCCP International Satellite Cloud Climatology Project Started in July 1983 Measures IR and visible radiances from weather satellites; radiance data used to characterize cloud radiative properties and improve cloud modeling in GCMs Data is continually improved; most recent cloud data set is D data, C data set is the previous one, etc.

5 Source Data: TSI (ACRIM) Active Cavity Radiometer Irradiance Monitor measurements of Total Solar Irradiance Composite satellite data from 1980 to present

6 Source Data: CRF Cosmic Ray Flux data exists for several stations back to the 1950s Recorded by ground-based neutron monitors Cosmic rays are ~90% protons, ~9% alpha particles, and trace heavier elements

7 Cosmoclimatology says Correlation between low-level cloud cover and cosmic rays Clouds from ISCCP C2 geostationary satellite data, land excluded Cosmic ray flux from Huancayo, Peru station

8 Correlation between clouds and cosmic rays does not exist over land, or over the ocean other than the Atlantic, and even then the trend seen in the data is statistically insignificant with a larger temporal data set ( ) (D2 used) Critics say

9 Cosmoclimatology says The Antarctic temperature trend is the opposite of that in the Northern Hemisphere, which must be a result of cloud forcing caused by cosmic rays

10 Critics say Fails to address, consider, or dispel any other explanation for Antarctic clouds: Ozone holeinduced changes in polar winds

11 Cosmoclimatology says Past ice ages correspond to solar crossings of galactic spiral arms, which produced increased cosmic rays (from Shaviv and Veizer, 2003)

12 Critics say Circular logic: claims the climate lines up with the crossing of galactic arms, but then uses the climate record to determine the mass and speed of the rotation; later goes on to say that the data beyond 200Myr isn t even very good Periodicity of cycles is subject to very loose interpretation and don t completely coincide among themselves 100, 190, 280, and 420 Myr BP matched to 30, 170, 360, and 470 Myr BP the three CRF minima (at ~80 m.y., 250 m.y., 420 m.y. BP) coincide with the age clusters (at ~140 m.y., 250 m.y., 360 m.y. BP)

13 Critics say Another recent paper on biological extinction calculates completely different crossing times Meteorite record interpreted differently, not taking into account collision effects which result in grouping of ages as is generally done Bottom line: one interpretation of CRF is taken as absolute fact when there are multiple interpretations and great uncertainty in age

14 Some experimental evidence? Adding ions from cosmic rays to air with trace ozone, sulfur dioxide, and water vapor increases nucleation rates Experimental verification of ion-nucleation correlation under those conditions

15 CLOUD Cosmics Leaving OUtdoor Droplets Experiment planned to begin at CERN next year Use the Proton Synchrotron to simulate cosmic rays, study the underlying microphysics of the cloud-cosmic ray interaction

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17 So are cosmic rays responsible for climate change? There is some experimental evidence linking ionization to increased CCN, but at this point more evidence is required Main proponents dismiss all other theories of climate change in favor of their own More study, especially the CLOUD experiment, should better determine the role cosmic rays play in the climate system, under which conditions; it s likely somewhere in between

18 References Svensmark, H., Cosmoclimatology: a new theory emerges. A&G, Feb. 2007, Vol. 48 Svensmark, H. and E. Friis-Christensen, Variation of cosmic ray flux and global cloud coverage A missing link in solar-climate relationships, J. Atm. Solar-Terr. Phys., Vol. 59, No. 11, , 1997 Svensmark, H., J. Pedersen, N. Marsh, M. Enghoff, and U. Uggerhøj, Experimental evidence for the role of ions in particle nucleation under atmospheric conditions, Proc. R. Soc. A , , doi: /rspa Shaviv, N., and Veizer, J., Celestial driver of Phanerozoic climate?, GSA Today, July 2003 Marsh, N.D., and H. Svensmark, Low Cloud Properties Influenced by Cosmic Rays, Phys. Rev. Lett., Vol. 85, No. 23, 4 Dec 2000 Sun, B., and R.S. Bradley, Solar influences on cosmic rays and cloud formation: A reassessment. J. Geophys. Res., Vol. 107, No. D14, 4211, /2001JD000560, 2002 Marsh, N., and H. Svensmark (2004), Comment on Solar influences on cosmic rays and cloud formation: A reassessment by Bomin Sun and Raymond S. Bradley, J. Geophys. Res., 109, D14205, doi: /2003jd Sun, B., and R. S. Bradley (2004), Reply to comment by N. D. Marsh and H. Svensmark on Solar influences on cosmic rays and cloud formation: A reassessment, J. Geophys. Res., 109, D14206, doi: /2003jd Rahmstorf, S. et al., Forum: Cosmic Rays, Carbon Dioxide, and Climate, Eos: Transactions, AGU, Vol. 85, No. 4, 27 January 2004 Schmidt, G., Clouding the issue of climate, ISCCP website: ACRIM website: