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The Chilling Stars A new theory of climate change. Henrik Svensmark, Center for Sun Climate Research Danish National Space Center. Basel, Marts2007. Cosmic Rays and Climate. CLIMATE. COSMIC RAYS.
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The Chilling StarsA new theory of climate change Henrik Svensmark, Center for Sun Climate Research Danish National Space Center Basel, Marts2007
Cosmic Rays and Climate CLIMATE COSMIC RAYS Variations in Cosmic Ray Flux Affects Earths Climate, and Cause Variations in Climate. Examples with Solar Modulated Cosmic rays
What are Cosmic Rays? Heliosphere, Cosmic Rays and Solar Activity
Coronal Mass Ejections (CME) Movie One month of observation
Cosmic ray shower (Movie) About 70 muons/s /m2 at the Earths surface In 24 hours about 12 million muons goes through a human body
Cosmic rays and climate over the last 10.000 years Bond et al, Science 294, 2001 Last 1000 years Little Ice Age • Little Ice Age is merely the most recent of a dozen such events during the last 10.000 years
Possible physical mechanism • Mechanism that amplifies tiny GCR energy input
Link between Low Cloud Cover and Galactic Cosmic Rays? Svensmark & Friis-Christensen, JASTP 1997, Svensmark, PRL 1998, Marsh & Svensmark, PRL, 2000. (update 2005)
CLOUDS COSMIC RAYS Micro-physical Mechanism? CLIMATE Experimental Studies at DNSC in Copenhagen
Aerosol formation and growth Possible link between clouds and cosmic rays CN (Condensation Nuclei) Cloud Drop H2SO4 & Water & Organic Vapors UCN (Ultra Fine Condensation Nuclei) CCN (Cloud Condensation Nuclei) Size 0.1 mm 0.001 mm 0.01 mm 10 mm Nucleation process has been a mystery
- + Cosmic Ray Ionization & Aerosol formation and growth CN (Condensation Nuclei) Cloud Drop H2SO4 & Water Vapors UCN (Ultra Fine Condensation Nuclei) CCN (Cloud Condensation Nuclei) Size 0.1 mm 0.001 mm 0.01 mm 10 mm What is the importance of IONS ?
Gamma source Gamma source Muon detector Radon detector SO2 O3 H2O
q (cm-3 s-1) 0 10 20 30 40 50 60 Steady state experiment H2SO4 concentration ~ 2*108 (cm-3) O3 ~ 25 ppb SO2 ~ 300 ppt RH ~ 35% Svensmark et al. PRA 2006
Next experiment ( How to stop cosmic rays) Äspö Hard Rock Laboratoriet, Sweden Surface 70 /s/m2 500 m 100 m 0.7 /s/m2 200 m 0.07 /s/m2 However radon is a concern - lead shield Hopefully an experiment will take place with near zero ionization in spring 2007
Hard Rock Laboratory, Aspø Sweden ~ 500 meter of rock
Micro-physical Mechanism? GALACTIC PROCESSES CLOUDS COSMIC RAYS Micro-physical Mechanism? CLIMATE
Starformation, Super Novae and Cosmic Rays The Milky Way, Super Novae and Cosmic Rays
Birdseye view of Milkyway Svensmark A&G 2007
Cosmic rays and spiral arm crossing 0 Estimated Cosmic Ray Flux 0.5 1 1.5 600 0 200 400 Million of Years Shaviv, PRL (2002)
What about longer time scales, i.e over the history of the Earth 4.6 Billion years? • Although Cosmic ray fluxes are not known so far back • in time, they can be constructed from knowledge of • Solar Evolution • History of Star Formation Rate in the Milky Way
Solar Evolution Insight to the evolution of our Sun is gained from extensive studies of solar proxies with ages from 100 Myr to 10 Gyr The young Sun was rotating at a rate at least 10 times faster than today. As a consequence, 1) The Sun had a vigorous magnetic activity 2) Coronal X-ray and EUV emissions up to 1000 times stronger than today. 3) The Sun had a denser solar wind A better shilding of Cosmic rays Pressure balance Heliopause
Starformation, Super Novae and Cosmic Rays Solar Evolution, Star Rate Formation and Cosmic Rays Svensmark, Astronomical Notes 2006
Starformation, Super Novae and Cosmic Rays Solar Evolution, Star Rate Formation and Cosmic Rays Svensmark, Astronomical Notes 2006
Starformation, Super Novae and Cosmic Rays Cosmic Rays and the Biosphere in 4 Billion Years C = 0.92 10 GeV Svensmark, Astronomical Notes 2006
Starformation, Super Novae and Cosmic Rays The Argumentation is Based on the Following Assumptions About Cause and Effects • Variations in Star Formation Rate in the Milky Way and Solar Evolution Cause Variations in the Cosmic Ray Flux Impacting Earth. • Variations in Cosmic Ray Flux Cause Variations in Climate. • Variations in Climate Cause Variations in total Biological Productivity.
Starformation, Super Novae and Cosmic Rays Carbon Isotopes The various reservoirs of carbon on Earth (limestone, biota and CO2 in atmosphere) If more carbon is stored in one of these reservoirs, the isotopic composition of others reservoirs changes to reflect that storage. For instance: if there is more carbon stored in organic matter which is isotopically light, the average carbon composition of dissolved carbon in the ocean and carbon dioxide in the atmosphere will become heavier.
Starformation, Super Novae and Cosmic Rays Carbon 13 during 3.8 billion years Standard deviation In steps of 400 mill yr Svensmark, Astronomical Notes 2006
Starformation, Super Novae and Cosmic Rays Cosmic Rays and the Biosphere in 4 Billion Years C = 0.92 10 GeV Svensmark, Astronomical Notes 2006
Snowball Earth Hofman and Schrag point to cap carbonate abruptly above glaciomarine dropstone
Starformation, Super Novae and Cosmic Rays Cold Climate Large temperature difference between equator and pole Strong winds – Mixing of Nutriants Large biological productivity Large fluctuations biological productivity possible Cold Warm Ice Pole Equator
Starformation, Super Novae and Cosmic Rays Hot Climate Small temperature difference between equator and pole Weak winds – Little Mixing of Nutriants Small biological productivity Small fluctuations in biological productivity Warm Hot Pole Equator
Conclusion • Particles from space seems to influence Earths climate, • ranging from years to 109 years. • Part of the missing physical mechanism has been demonstrated experimentally • Involving ions and aerosol formation • Linking to clouds and thereby the energy budget of the Earth • Understanding the cosmic ray climate link could have large • implications in our understanding of climate changes and possible evolution on Earth. • The evolution of the Milky Way and the Earth is linked • It is not suggested that it is the only cause of climate change.
Center for Sun-Climate Research The team: Martin Enghoff Nigel D. Marsh Jens Olaf Pedersen Ulrik I. Uggerhøj Henrik Svensmark