Transcript Cosmic Rays and Climate

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
COSMIC RAYS
CLIMATE
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)
One month of observation
Movie
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 in a Cloud Chamber (movie)
Cosmic rays and climate over the last millennium
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
8
the last 10.000 years
How can STARS influence Climate?
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
H2SO4
&
Water
&
Organic
Vapors
CN
Cloud Drop
(Condensation Nuclei)
UCN
CCN
(Ultra Fine Condensation Nuclei)
(Cloud Condensation Nuclei)
Size
0.001 mm
Nucleation process
has been a mystery
0.01 mm
0.1 mm
10 mm
Cosmic Ray Ionization &
Aerosol formation and growth
+
H2SO4
&
Water
CN
Cloud Drop
(Condensation Nuclei)
-
Vapors
UCN
CCN
(Ultra Fine Condensation Nuclei)
(Cloud Condensation Nuclei)
Size
0.001 mm
What is the importance of
IONS ?
0.01 mm
0.1 mm
10 mm
Gamma source
SO2
O3
H2O
Gamma source
Muon detector
Radon detector
Steady state experiment
q (cm-3 s-1)
0
10
20 30 40 50 60
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)
500 m
Äspö Hard Rock Laboratoriet, Sweden
Surface 70 /s/m2
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
CLOUDS
COSMIC
RAYS
Micro-physical
Micro-physical
Mechanism?
Mechanism?
GALACTIC
PROCESSES
CLIMATE
Starformation, Super Novae and Cosmic Rays
The Milky Way, Super Novae and Cosmic Rays
The Milky Way, Super Novae and Cosmic Rays
Birdseye view of Milkyway
Svensmark A&G 2007
0
0.5
1
1.5
600
200
400
Million of Years
Estimated Cosmic Ray Flux
Cosmic rays and spiral arm crossing
0
Shaviv, PRL (2002)
Svensmark A&G 2007
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
1. Solar Evolution
2. 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
R(t )  VM (t ) / PISM
Pressure balance
2

MV / R
PLIM
Heliopause
(t )   0 M (t ) M 0
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
Formation and interaction between galaxies
Minor merger (dawfgalaxy) with spiral galaxy
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
1. Variations in Star Formation Rate in the Milky Way
and Solar Evolution Cause Variations in the Cosmic
Ray Flux Impacting Earth.
2. Variations in Cosmic Ray Flux Cause Variations in
Climate.
3. 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
Warm
Cold
Ice
Equator
Pole
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
Hot
Equator
Warm
Pole
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.
The team:
Martin Enghoff
Nigel D. Marsh
Jens Olaf Pedersen
Ulrik I. Uggerhøj
Henrik Svensmark
Center
for
Sun-Climate Research