possible effects of galactic cosmic rays on climate and...
TRANSCRIPT
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Possible effects of galactic cosmic rays
on climate and weather
Heliosphere
ⒸHayashi
Sun
EarthCollaborators
Yusuke Yokoyama (AORI, The Univ. of Tokyo)
Wataru Sakashita (AORI, The Univ. of Tokyo)
Yasuhiko T. Yamaguchi (AORI, The Univ. of Tokyo)
Takeshi Nakatsuka (Nagoya University)
Hong K. Peng (The Univ. of Tokyo)
Yukihiro Takahashi (Hokkaido University)
Mitsuteru Sato (Hokkaido University)
Hiroyuki Matsuzaki (MALT, The Univ. of Tokyo)
Fuyuki Tokanai (Yamagata Univ)
Yosuke Yamashiki (Kyoto Univ)
Shuhei Masuda (Jamstec)
John P. Matthews (Kyushu Univ)
Kazuki Munakata (Shinshu Univ)
Ryuho Kataoka (Tokyo Tech)
Hiroko, MIYAHARA (宮原ひろ子)ICRR → Musashino Art University
miyahara(at)musabi.ac.jp
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Topics
• Radiocarbon dating
• Reconstruction of Galactic Cosmic Rays (GCRs) and
solar activity in the past
• GCR variations at the Maunder Minimum (AD1645-
1715)
• Detecting the GCR impact on climate variations
• Possible pathway of GCR impact on climate system
• 27-day solar rotational period found in tropical cloud
activities and global lightning activities
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Production
of carbon-14
http://www.physics.arizona.edu/ams/education/product.htm
GCRs are modulated by
heliospheric & geomagnetic
magnetic field
Sun
Earth
Heliospheric
magnetic field
geomagnetic field
GCRs
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Radiocarbon dating
Present
concentration
Before AD1993, the variations of carbon-14 production
had not been taken into account.
Radiocarbon age
Ca
rbo
n-1
4 c
on
ce
ntr
atio
n
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Construction of the
Calibration Curve
for the radiocarbon
dating
Long sequence of
tree rings were
obtained by
matching the pattern
of tree-ring widths
(Dendro-chronology)
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The “wiggles” in the calibration curve is due to
1. the secular variation of geomagnetic field intensity (>3000 yrs)
2. solar magnetic field variations (<3000 yrs)
Probability distribution
of carbon-14 date
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Regional offset of carbon-14 concentration
International curve
Japanese Calibration curve
(yrs)
Ra
dio
carb
on
ag
e
Old CO2
with less
carbon-14
(National Museum of Japanese History)
Calibrated Date (AD)
Common pattern
+ occasional offset
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Regional effect of Beryllium-10
concentration in ice core
(Steinhilber et al., PNAS, 2012)
Common pattern
+ occasional offset
EDML: Antarctica
GR: Greenland
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“Best” reconstruction of cosmic ray intensity
obtained by Principal Component Analysis
of all of the data available so far.
(Steinhilber et al., PNAS, 2012)
Red: Secular variation of geomagnetic field intensity
Residue: 100-300 yr variations of solar activity level
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Uncertainty
also comes from
the secular varia-
tion of geomagne-
tic field intensity
(Steinhilber et al., PNAS, 2012)
(remanent magnetization)
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Cause of the uncertainties in the
reconstructed incident GCR flux
• Regional climate effect (geographical)
• Global climate effect (deduction of oceanic
circulation, change in carbon cycle etc.)
• Uncertainty of reconstructed geomagnetic
field intensity
• (Measurement errors)
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Deriving the information of Galactic
Cosmic Rays (GCRs) and solar activity
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Solar modulation of Galactic Cosmic Rays (GCRs)
・Charged particles (mainly protons)
・Accelerated at supernova remnant
・diffusion
・advection by solar wind
・ B×∇B drift
Solar max
Solar min
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“11-year” cycles of solar
activity and the flux of
galactic cosmic rays
(SOHO)
- + - +
Solar magnetic polarity
Clim
ax
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1600 1700 1800 1900 20000
100
200
300
Sunspot
num
ber
Maunder
Minimum
Dalton
Minimum
(Decadal)
MaunderSpoerer
WolfDalton
Oort
~9 yrs
~12 yrs
~10.5 yrs ~10 yrs
~13.5 yrs ~14 yrs ~13 yrs
14C
(perm
il)
~11 yrs(+/- 1yr)
~11 yrs
-30
-10
10
30
800 1100 1400 1700 2000
Year AD
Actual mean length
over the shaded period
Dacadal:
Stuiver et al., 1998
Annual:
Miyahara et al.,
2004, 2006,
2007, 2008
Carbon-14 in annual tree rings
Annually resolved measurement of carbon-14
Example of spectral analysis (Wavelet transform)
(Miyahara et al., 2010)
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Amplified “22-year” period in GCRs
at the Maunder Minimum
1550 1600 1650 1700 1750 1800 1850 1900 1950 20000
100
200
300
Sunspot
num
ber
1550 1600 1650 1700 1750 1800 1850 1900 1950 20000
0.005
0.01
0.015
0.02
0.025
Year AD
10B
e f
lux (
ato
ms/c
m2/s
)
Maunder
Minimum
10Be in Greenland Ice core
Dalton
Minimum
Berggren et al., 2009
Hoyt & Schatten, 1998
qA<0 qA>0
max min max min max
Cosm
ic r
ays (
%)
Oulu neutron monitor data
40%
Kataoka, Miyahara et al., 2012
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Tilt
an
gle
(d
eg
ree
)
Year AD
22-year period of solar magnetic polarity reversals
S
N
N
S
Neutral sheet
(current sheet)
Tilt angle
Su
nsp
ot N
um
be
r
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Heliospheric current sheet
(based on Washimi et al.)
Solar max Solar min
One wave = ~ 5AU
⇒100AU = 20 months
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(based on Washimi et al.)
Negative
polarity
Drift effect of cosmic rays
Solar max Solar min
※ B×∇B drift
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(based on Washimi et al.)
Positive
Polarity
Drift effect of cosmic rays
Solar max Solar min
※ B×∇B drift
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Solar min
Solar max
Solar min
Solar max
Modern: 5-75 degrees
If 0-75 degreesIf 30-75 degrees
Solar min
Solar max
1. Solar polarity
2. Tilt angle
Expecte
d c
osm
ic r
ays
Kota&Jokipii, 2003
Tilt angle vs GCR fluxMiyahara et al., 2010
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(a) 0 deg. at cycle min
(b) 5 degs. at cycle min
(a)
Heliospheric
Magnetic field
Based on
Kota&Jokipii, 1983; 2003
Possibly extremely flattened current sheet at the
Maunder Minimum
Earth
The
Sun
40%
Kataoka, Miyahara et al., 2012
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Detecting the GCR impact on climate variations
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Ice
Ra
fte
d D
eb
ris
Evidence from the past:
Influence of Solar activity on climate variations
Bond et al., 2001
Bond et al., 2001
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Promotion of
chemical reaction
in the stratosphere
Ozone formation
Ozone heating
Possible mechanisms of
solar influence on climate change
Solar activity
Attenuation of cosmic rays
Solar irradiance
Total / UV
Solar wind
Particles
(proton, etc.)
Solar/heliospheric
magnetic field
Climate change
Cloud properties
Nucleation Coagulation
~0.1%
~20%Promotion of
chemical reaction
in the mesosphere
NOx formation
Ozone destruction
unknown
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How to detect the cosmic ray effect?
・ Astronomical phenomena
・ Geomagnetic Excursions / M-B Geomagnetic Reversal
・ Forbush Decrease (daily)
・ Maunder Minimum/Medieval Period
・ Maunder-like period during the Glacier period
・ Nuclear bomb test/nuclear power plant accident
・Positive results (Kniveton , 2004; Svensmark, 2009; Kataoka 2010)
・Negative results (Sloan & Wolfendale, 2008; Kristjánsson+, 2008; Calogovic+, 2010)
・ Under much more ice forming condensation nuclei (suggested by Tinsley, 2009)
・ unique periodicities ~22-years in cosmic rays (Miyahara+, 2008; Yamaguchi+, 2010)
・ Crossing the galactic arms (Shaviv, 2003)
・ Vertical oscillation of solar system in the galaxy (Medvedev & Melott, 2007)
・ Some evidence of cooling from low latitude region (Kitaba et al., 2010; 2012)
・ No effect found (Erlykin et al., 2009)
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Kitaba et al., PNAS, 2012
A: Paleo-geomagnetic field intensity anomaly (Hyodo et al., 2006)F: Calculated galactic cosmic ray intensity (inverted)G: Reconstructed annual mean temperature around Osaka (Kitaba, 2010, Kitaba et al., 2012)
TEDE: 冷温帯落葉広葉樹林WAMX: 暖温帯常緑広葉樹林
Evidence from the Matsuyama-Burunhes Geomagnetic reversal
40%↓ 50%↑ 1-4℃↓
How to detect the cosmic ray effect?
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Humid
Dry
Cold
10
Be
flu
x N
GR
IP
(ato
ms c
m-2
s-2
)
Low
High
Te
mp
era
ture
in
de
xR
H a
no
ma
ly
Warm
Humidity in Japan around June
Greenland winter temperature
These spikes can be utilized to trace
GCR effect on climate system
GCR flux (with dating errors of 3-5yrs)
(Berggren et al., 2009)
Yamaguchi, Miyahara et al., PNAS, 2010
Climate response to cosmic-ray spikes during the Maunder Minimum
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Yamaguchi, Miyahara et al., PNAS, 2010
~4 sigma
GC
R a
no
ma
ly
Superposition of four 1-year spikes
for 14C (GCR) and 18O (climate)H
um
idity
Oxygen-18/Oxgen-16
Carbon-14/Carbon-12
(shifted by 1yr for the delay in carbon cycle) Climate system responds
to GCR with no time lag
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How GCRs affect climate system?
- Possible impact of GCRs on
tropical cloud activities
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Important findings of CLOUD
experiment at CERN
CERN experiment finds
・Nucleation is more efficient at lower temperature
(correspond to middle to upper troposphere)
・NH3 in addition to SO2 is needed for efficient
nucleation
Kirkby et al., Nature 2011
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Geomagnetic cut off regidity (GV)
6km
Usoskin et al., 2004
Height (mb)
Ionization by GCR at 15GV
・Sufficient water vapor & SO2
・Low temperature
・Sufficient ionization
Kazil, 2006
Where can be the most
sensitive place?
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Solar rotational period in tropical cloud activity
Takahashi et al., ACP, 2010
Hong, Miyahara et al., JASTP, 2010
27-days
54-days120-140 E, 0-20 N
Frequency spectrum of Cloud height
Solar max
Solar min
27-day signal Solar max
Solar min
Less 27-day signal
54-days
※Monthly-scale cloud activity is known to present at
Equatorial region (Madden-Julian Oscillation)
but the origin of the cyclicity is unknown.
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Solar rotational period
in lightning activity
Muraki et al., 2004
Sato et al., 2005
Global
Japan
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Solar flare and Forbush decrease
Forbush decreases
太陽フレア
Kataoka 2009
Sector structure
(AD2000)
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Next step:
Observational study on the GCR
effects on cloud microphysics
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Future prospects
• Trace the impact of GCR on equatorial cloud
activities and its propagation by utilizing the 27-day
GCR variations
• Improve the accuracy of climate and weather
forecast
• Search for the impact of astrospheres on the climate
condition of extra-solar planets
• Reinterpretation of the history of the Earth