Download Cosmic Rays and Climate

Cosmo-Climatology
Cosmic rays, Clouds, and Climate
Henrik Svensmark,
Center for Sun Climate Research
Space- DTU
Cosmic Rays and Climate
CLOUDS
CLIMATE
COSMIC RAYS
Super Novas
Star formation
Supported by empirical,
observational, and
experimental evidence
Variations in Cosmic Ray Flux Cause Variations in Earths Climate.
What are Cosmic Rays?
Heliosphere, Cosmic Rays and Solar Activity
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
According to icecores
CO2 levels has been
constant ~280 ppm
Last 1000 years
Little Ice Age
• Little Ice Age is merely the most recent of a dozen such events during
5
the last 10.000 years
Adapted from Kirkby
Cosmic rays and climate over the last millennium
”Since everybody
thought that the
continous crop faliure
was caused by witches
from devilish hate, the
Low
Cosmic ray flux
whole contry stood up
Warmer
Climate
for their eradication”
High
Cosmic
ray flux
Johann
Linden Travis
ca. 1590Climate
Colder
Adapted from Kirkby
How can STARS influence Climate?
Net effect of clouds is to cool the Earth by about 30 W/m2
Link between Low Cloud Cover and Galactic Cosmic Rays?
ISCCP IR Low cloud data
Calibration?
Svensmark & Friis-Christensen, JASTP 1997, Svensmark, PRL 1998, Marsh & Svensmark, PRL, 2000. (update 2005)
Cosmic Rays and 1960 -2008 tropospheric temperatures
Average temperature
between 0-10 km
STEP!
Using the oceans as a calorimeter to quantify the solar radiative forcing
Nir J. Shaviv JGR 2009
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
Atmospheric conditions!
Gamma source
SO2
O3
H2O
SKY experiment
2002 - 2006
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. Proc. R. Soc. A (2007) 463, 385–396
Coronal Mass Ejections
Natural experiments for testing the GCR-atmosphere link
AERONET, SSM/I, MODIS and ISCCP data for
5 strongest Forbush decreases
Aerosols
Clouds
Cosmic Rays and Climate
~10%
~100%
CLOUDS
CLIMATE
COSMIC RAYS
Super Novas
Star formation
Supported by empirical,
observational, and
experimental evidence
Variations in Cosmic Ray Flux Cause Variations in Earths Climate.
SN variations and Earths Climate
Svensmark 2008
Conclusion
Particles from space (Cosmic Rays) influence Earths climate,
ranging from days to 109 years.
•The empirical evidence is large and strong
Part of a physical mechanism has been demonstrated
experimentally
• Involving ions and aerosol formation
• Linking to clouds and thereby the energy budget of the Earth
Clouds are forcing the Earths climate rather than being a
passive component.
Understanding the cosmic ray climate link is necessary if we
want to understand natural climate changes.
The evolution of the Milky Way and the Earth is linked