http://starviewer.wordpress.com/2009/12/08/climategate-todos-los-cientificos-de-mayor-prestigio-contra-al-gore-mas-de-700-cientificos-internacionales-discrepan-de-la-teoria-y-advertencias-sobre-la-actividad-humana-como-causa-del-cambio-clima/ Fuente original CERN - Ginebra: http://indico.cern.ch/getFile.py/access?resId=0&materialId=slides&confId=52576

1. Cosmic rays and climate
Jasper Kirkby /CERN
CERN Colloquium, 4 June 2009
1

2. 1. Present climate change
2

3. Climate forcings (IPCC 2007)
Global Land-Ocean Temperature Index
.6
GISS
Annual Mean
.4
Temperature Anomaly (°C)
5-year Mean
.2
.0
-.2
-.4
1880 1900 1920 1940 1960 1980 2000
• 0.7oC rise since 1900 (not uniform)
• IPCC findings:
‣ Total anthropogenic 1.6 W/m2
(≅ 1 candle per 25 m2)
‣ Negligible natural (solar) contribution: 0.12 W/m2
‣ Clouds poorly understood
3

4. Why clouds are important for climate change
John Constable, Cloud study, 1821
• Clouds cover ~65%
of globe, annual
average
• Net cooling of
30 W/m2
• c.f. 1.6 W/m2 total
anthropogenic
4

5. NASA CERES satellite
• Data from CERES satellite (Clouds and Earth’s Radiant Energy System)
• Clouds (and oceans) are poorly simulated in climate models
(finest grid sizes ~100 km x 100 km)
5

6. II. Evidence for pre-industrial solar-climate
variability
• Numerous palaeoclimatic reconstructions suggest that
solar/GCR variability has an important influence on climate
• However, there is no established physical mechanism, and
so solar-climate variability is:
‣ Controversial subject
‣ Not included in current climate models
6

7. Little Ice Age and the sunspot record
The frozen Thames, 1677
200 200
Sunspot number
Little Ice Age Dalton
Minimum
100 100
Maunder Minimum
0 0
1600 1650 1700 1750 1800 1850 1900 1950 2000
Year
• Inactive sun (low sunspot peak, long cycle length) cold climate
• Active sun (high sunspot peak, short cycle length)
7
warm climate

8. 1000 1200 1400 1600 1800 2000
Global climate - last 2000yr
Greenland surface temperature (oC)
a) Northern hemisphere temperature
0.4
Medieval Warm Little Ice Age
Temperature anomaly ( C)
o
instrumental
•
-32 GRIP -31
-20.6 Dye 3 -19
Little Ice Age and
0
hockey stick
-0.4 multi-proxy
Medieval Warm Period
•
(tree rings, pollen,
shells, stalagmites, etc.)
Greenland boreholes (rhs)
Global observations
-0.8
worldwide boreholes
b) Galactic cosmic rays 10Be (Greenland) high GCR flux cool climate
GCR change (% from 1950 value)
-10 14C (rh scale)
(arb. scale) -20
Carbon-14 anomaly (x 10-3)
low GCR flux warm climate
0
10
increasing GCR
0
20
Austrian speleothem:
30 10Be (South Pole) 320
20 CO2
(lh scale) CO2
(ppm)
40 290
c) Tropical Andes glaciers -10 -8.0
0 GCR
Lake Mucubaji magnetic
susceptibility (SI x10-6)
!18O
GCR/ 0 (‰)
-7.5
"14C
glacial advance
3
(‰)
10 1oC
!18O
6 -7.0
Mangini et al., EPSL 235 (2005)
20
500 1000 1500 2000
Year (AD)
1000 1200 1400 1600 1800 2000
Year (AD) 8

9. Siberian climate - last 700 yr
• Correlation recently reported between solar/GCR
variability and temperature in Siberia from glacial ice core
• 30 yr lag (ie. ocean currents may be part of response)
Eichler et al. GRL 36 (2009)
Siberia temperature (oC)
solar/GCR (rhs): 10Be
2
14C 4
Solar modulation
1 temperature
(lhs) 2
(! units)
0
0
-1
-2
1300 1400 1500 1600 1700 1800 1900 2000
Year
9

10. N. Atlantic ice rafted debris - last 10 kyr (Holocene)
Bond et al, Science 294, 2001
Cosmic rays: Ice-rafted
debris (%):
Low cosmic -0.4 GCR -4 Less
ray flux (10Be) ice
0.0 0
ice-rafted
debris
0.4 4
High cosmic More
ray flux ice
Little Ice Age
Low cosmic -0.1 Medieval Warm -4 Less
ray flux ice
0.0 0
haemetite-stained grains quartz grains
0.12 mm
0.1
GCR 4
High cosmic More
ice-rafted debris (14C)
ray flux ice
12 10 8 6 4 2 0
Calendar age (kyr BP)
Icelandic glass grains foraminifera
• LIA is merely the most recent of 10
around 10 such events in Holocene

11. GCR influence on ITCZ/monsoon in Little Ice Age?
high GCR flux southerly ITCZ shift
low GCR flux northerly ITCZ shift
Drier in LIA
Wetter in LIA
ITCZ
displacement
D11 during LIA
D7
July ITCZ D5 D8 D10 D13 D12
D6 D9
W0 Equator
W2
January ITCZ W4
W3
W1
11

12. Indian Ocean monsoon - 6.5-9.5 kyr ago
U. Neff et al. (Nature 411, 2001)
high a 14C (GCR intensity) dry 510 ± 30
1400 ± 30
GCR 10 3010 ± 60
3740 ± 130
–3.5 3790 ± 140
5
4380 ± 260
IT C Z
O (‰ VPDB)
–4.0 4370 ± 100
0
C (‰)
4900 ± 140
–5 –4.5 5750 ± 100
Jun-Aug
14
6540 ± 180
monsoons
18
–10 –5.0 6960 ± 50
7910 ± 210
8880 ± 90
8870 ± 230
–15 –5.5
low 9760 ± 150
10 cm
18
O (rainfall) 10,060 ± 210
GCR wet High pres s ure 10,470 ± 170
6.500 7.000 7.500 8.000 8.500 9.000 9.500
Age (kyr BP)
high 10 dry
b 14C (GCR intensity)
GCR
5
• Solar/GCR forcing of Indian
–4.0
0
–5 –4.5
O (‰ VPDB)
Ocean monsoons (ITCZ
C (‰)
–10 migration) on centennial—even
14
–5.0 decadel—timescales
18
–15
–20 18
O (rainfall)
low –5.5
GCR wet
7.900 8.000 8.100 8.200 8.300
Age (kyr BP) 12

13. Solar-climate mechanisms
• Candidates for
Global mean temperature (0C)
0.15
solar-climate variability: 0.10
solar irradiance
estimated forcing
Lean et al. (1995)
(MAGICC GCM)
‣ direct effect: 0.05
✦ total solar irradiance 0
-0.05 Lean et al. (2002)
✦ solar UV
-0.10
‣ indirect effect: 1600 1650 1700 1750 1800 1850 1900 1950 2000
Year
✦ galactic cosmic rays (GCRs) /ionising particles
• Can be resolved in principle since GCRs are, in addition to
11-year solar cycle, modulated by:
‣ solar magnetic disturbances (esp. high latitude effects)
‣ geomagnetic field (low latitude effects)
‣ galactic environment
13

14. Asian monsoon and geomagnetic field
East Asian monsoon instensity; Wang et al., Nature 451, 2008
440
Monsoon
intensity
–12
N. Hemisphere summer
2! U-Th dating errors
18 O (‰, VPDB)
insolation (W m-2)
–11 420
–10 400
–9
380
–8
–7 360
Sanbao/Hulu caves, China
0 20 40 60 80 100 120 140 160 180 200 220
Age (kyr BP)
Knudsen & Riisager, GSA 2009
Geomagnetic dipole moment (1021Am2)
0.4
monsoon intensity
–7.0 120 residuals for last 5000yr 20
geomagnetic field Asian monsoon
Summer insolation, 30N (W m-2)
dipole moment (1021Am2)
460 0.2
(± 2! band)
(‰ VPDB)
–7.4 10
100
18 O (‰ VPDB)
0.0
–7.8 470 0
summer 80
monsoon intensity
18O
–8.2 insolation –0.2 geomagnetic field
480 –10
Asian monsoon
–8.6 60 –0.4
(Dongge Cave, China) –20
490
r (0–5000 BP) = 0.86 r (0–5000 BP) = 0.71
–9.0 40 –0.6 –30
0 1000 2000 3000 4000 5000 6000 7000 8000 9000 0 1000 2000 3000 4000 5000
Age (yr B.P.) Age (yr B.P.)
• Asian monsoon controlled by orbital insolation - with strong millennial-scale variability
• Possible influence of geomagnetic field on Asian monsoon?
• Opposite sign of effect: lower B field → increased GCR → increased monsoon intensity,
which could result from latitudinal differences of solar- and geomagnetic modulations
14

15. Galactic modulation of climate? - 500 Myr
CO2 GCR
icehouse
greenhouse
Shaviv & Veizer,
GSA Today, 2003
• Orbital period of Sun/Earth around Milky Way ~550Myr
• High GCR flux in spiral arms => 140 Myr period
• Same period and phase found in benthic sea temperature (4oC amplitude) and ice
age epochs (icehouse/greenhouse)
15

16. III. Solar variability in the 20th century
16

17. Sun (photosphere) seen in visible (677nm) at solar max (2001)
NASA/ESA
SOHO
17

18. Sun (corona) seen with extreme UV eyes (20nm)
NASA/ESA
SOHO
18

19. Cosmic ray changes during 20th century
0
galactic cosmic solar magnetic flux Lebedev balloon GCR data:
Solar magnetic flux (x1014 Wb)
rays 3.5
5 a) Murmansk
1.6
10
10Be concentration (x104 g-1)
3.0
Cosmic ray intensity (cm-2s-1)
Mirny
1.2
15
0.8 2.5 Moscow
0.4
10Be (GCR) weaker solar
2.0
modulation at low latitudes,
0 due to geomagnetic shielding
1700 1750 1800 1850 1900 1950 2000
Year
Alma-Ata
•
1.5
Solar open magnetic flux
increased by x2.3 in 20th century
•
b)
GCR net decrease by ~20% 200
Sunpot number
(mostly in 1st half of century) 100
• Largely only solar cycle variations
0
cycle
19
cycle
20
cycle
21
cycle
22
cycle
23
of GCR flux in 2nd half 1960 1970 1980 1990 2000
Year
19

20. Sea-level change in 20th century Year
1920 1940 1960 1980 2000
8
sea-level rate:
9 stations sunspot number
Holgate, GRL (2007) 177 stations <TOPEX
150 6 satellite>
Rate of sea level change (mm/yr)
200
Cumulative sea level change (mm)
Sunspot number (smoothed)
4
150
100
2 100
50 50
0
0
0 -2
1900 1920 1940 1960 1980 2000
Year -4
1920 1940 1960 1980 2000
Year (decade mid-point)
• Steady rise of sea-level; mean rate = 1.7 mm/yr
• No increase in rate during recent decades
• Thermal expansion of oceans (mainly) + land ice melting
• Rate of sea-level rise is strongly modulated
solar modulation? (but solar irradiance variation is too small)
20

21. Sea-level positive feedback
21

22. Recent global temperatures - last 30 yr
1.0 1.0
surface temperatures; thermometers
0.8 (Hadley and GISS) 0.8
Temperature anomaly (oC)
0.6 0.6
0.4 0.4
0.2 0.2
0 0
-0.2 -0.2
tropospheric temperatures;
-0.4 satellite microwaves (UAH) -0.4
-0.6 -0.6
1980 1985 1990 1995 2000 2005
Year
• Most of ~2 yr fluctuations due to
El Niño-Southern Oscillation (eg 1997-98)
+ volcanoes (El Chichon 1982, Pinatubo 1991)
• Satellite and radiosonde (tropospheric) data show
‣ less warming than thermometer measurements of surface
‣ no enhanced upper tropospheric warming, expected from GHG
• Mean global temperatures flat over last 8 years. Cause not known but
CO2 increasing, so must be natural forcing
22

23. Pacific Decadel Oscillation
• PDO (Hare 1996) is similar to ENSO (temperature anomalies and surface
winds), except for long (30 yr) periodicity and primary effect on Pacific NW
• PDO transitions coincide with gradient changes of global temperatures
• PDO may be shifting to negative phase
23

24. Sunspot weakening
Livingston and Penn, National Solar Observatory, Tucson, AZ
"Sunspots may vanish by 2015", submitted 2005 (rejected for publication)
Livingston and Penn, 2005 example measurements:
Sunspot magnetic field (G)
3000 0.0
Normalised central depth
Fe 1564.8 magnetic spliting 0.1
CN
2500 OH
0.2
2015
Fe I 1564.8
0.3
2000 Jan 2002
0.4
Jun 1991
OH
minimum B field for visible sunspots 0.5
1500 OH 1565.3
2000 2005 2010 2015 0.6
0.4 0.6 0.8 1.0 1.2 1.4 1.6
Year
! Wavelength (+1564 nm)
1.0
(Sunspot / photospheric) intensity
Sunspot contrast ‣ Temperature-sensitive molecular lines
(1.0 = invisible)
0.9
‣ Zeeman splitting of Fe I line
0.8
2014 ‣ Continuum brightness of sunspot umbrae
• Sunspot umbrae warming at 45K /yr
0.7
• Sunspot magnetic fields decreasing at 77 G/yr
0.6 • Independent of sunspot cycle
2000 2005 2010 2015
• Linear extrapolation sunspots vanish after
Year
2015 (like Maunder Minimum)
24

25. Current very low solar activity
•
Galactic cosmic rays (Oulu neutron monitor)
Counting rate change (%)
10
Currently one sunspot on
0 Sun, and GCRs high
• Next sunspot cycle 24 is
-10
very late
-20 • Mean sunspot cycle length
1980 1990 2000 2010 is 11.1 yr
Year
• Length of cycle 23 is now
Total solar irradiance (World Radiation Center, Davos) >13.1 yr
Solar Irradiance (Wm!2)
1368 cycle 21 cycle 22 cycle 23
0.1% • Last time such a long cycle
occurred was cycle 4
1366 (1784-1798) just before
the Dalton minimum -
1364
coincided with notable
1975 1980 1985 1990 1995 2000 2005 2010 cold period of few decades
Year
• We live in interesting
200 200
times for the Sun...
Sunspot number
Little Ice Age Dalton
Minimum
100
Maunder Minimum
100 (hopefully a blessing not a
0 0
curse)
1600 1650 1700 1750 1800 1850 1900 1950 2000
Year
25

26. IV. Physical mechanism
• GCRs/ionising radiation may affect cloud amount via:
‣ CCN number concentration, and/or
‣ ice particle formation in clouds
26

27. Radiative forcing from aerosols
cloud droplet
aerosol (CCN)
scattering and unperturbed cloud 1. increased cloud 2. increased cloud lifetime
absorption of albedo (drizzle suppression)
solar radiation
“direct effect” “indirect effect”
(more cloud droplets) cloud droplet
(~10-20 m)
• All cloud droplets form on aerosol “seeds” known as
cloud condensation nuclei - CCN
• Cloud properties are sensitive to number of droplets
• More aerosols/CCN
=> brighter clouds, with longer lifetimes
cloud condensation
nucleus (CCN)
(~100 nm)
27

28. Seeds for cloud formation
contrails ship tracks off N.America
• Aerosol particles = condensation seeds
• Charged particles = condensation seeds
(at very high supersaturations)
+
- + - +
- +
- -
+
• Can cosmic rays, under natural conditions,
influence aerosols, clouds and climate?
bubble chamber
28

29. Possible mechanism
• Important source of cloud
condensation nuclei is gas-to-particle tion
critical cluster
! Gibbs free energy
ora
spo
conversion: p neutral nucleation
a
ev barrier
nta
cluster
trace gas → CN → CCN
neo
0
us
spo
•
n
gro
tan
Ion-induced nucleation pathway is eou
sg
wth
row
th
energetically favoured but limited by charged cluster
the ion production rate and ion lifetime 0 5 10
No. H2SO4 molecules
0.3 nm 1 nm 100 nm > 10 µm
galactic cluster critical
cosmic ion cluster
H 2O H 2O H 2O
rays H2SO4
HSO4¯
H2SO4
- H2SO4
- H2SO4
- cloud
NO3¯ cloud droplet
aerosol condensation
O2¯ neutral critical particle, nucleus, CCN
CN H3O+
cluster cluster
H 2O H 2O
ion pairs H 2O
H2SO4 SO42-
N 2+
H3O+
29

30. Is ion-induced nucleation globally important?
F. Yu et al., ACP 2008
Ratio of ion-induced nucleation rates to all primay aerosol sources
(dust, sea salt, black carbon, organic carbon) - for lowest 3km altitude
.001 .01 .1 1 3 10 30 100 300 1000 10000
• Modeling studies:
‣ Kazil et al.
ACP 2006: “No”
‣ Pierce & Adams
GRL 2009: “No”
‣ Yu et al.,
ACP 2008: “Yes”
• All modeling studies depend on uncertain experimental parameters
• Atmospheric observations over land (boreal forest) suggest ~10-20% of new particles are
ion-induced (Laakso et al, 2007), but alternative model interpretation of same dataset (Yu
and Turco, 2008) find much higher fraction, ~80%
• Ion-induced nucleation likely to be more important over oceans and at high altitudes
(lower background aerosols, trace gas concentrations and temperatures) - but few
measurements exist
30

31. Aerosol production by solar cosmic rays
Mironova et al, GRL 2008
•
Aerosol Index (norm. variation)
Solar proton event 20 Jan 2005 (GLE)
highest SPE intensity sites (6 stars)
• TOMS satellite measurement of optical
depth/Aerosol Index (AI)
• Increase of sulphate/nitrate aerosol
• Further satellite/LIDAR observations
have been made of increased aerosol
production in atmosphere due to
ionising particles
31

32. Cloud observations
• Original GCR-cloud correlation made by Svensmark & Friis-Christensen, 1997
• Many studies since then supporting or disputing solar/GCR - cloud correlation
• Not independent - most use the same ISCCP satellite cloud dataset
• No firm conclusion yet - requires more data - but, if there is an effect, it is likely
to be restricted to certain regions of globe and at certain altitudes & conditions
• Eg. correlation (>90% sig.) of low cloud amount and solar UV/GCR,1984-2004:
Usoskin et al, GRL 2006
32

33. Global electrical circuit
ionosphere (>90 km altitude) +250 kV
+ + + + + + + + + + + + + + + + +
fair weather current fair weather
~ 2 pA m -2 field
~105 !
(fair weather + _ bipolar ion-
fair weather _ _ environment
value) +
+ +
current
highly charged _ _ cloud-perturbed
~1400A (J ~ 2.7 pA/m2) +_
aerosols + + + _+ field
region of net -
+ _ + +_+ _ + + positive charge
+ +
+ + + ++ + + ++ + + +
+ + +
+ + + + + + + + + + +
charge accumulation cloud layer
thunderstorm (low conductivity)
~200 ! 0.7 F ___ _ _ __ _
current generators aerosol _ _ _ _
_ _ +
+ __ region of net -
(40 flashes /s) scavenging _ + _
" = RC ~2min _
250 m
negative charge
bipolar ion-
environment
surface 0V Electric field
• Cosmic rays ionise atmosphere and control Earth-ionosphere conductivity
• Large aerosol charges at cloud boundaries => unipolar space charge region
• Can be entrained inside clouds and may affect:
‣ Rate of aerosol accretion by cloud droplets
‣ Ice particle formation
‣ Atmospheric dynamics
• Largest ionisation in polar regions; many observations of cloud and T/P changes
caused by Forbush decreases, solar disturbances, magnetic sector crossings...
33

34. V. CLOUD experiment at CERN
34

35. CLOUD collaboration
CLOUD Collaboration
31 May 2009
Austria:
University of Innsbruck, Institute of Ion Physics and Applied Physics
University of Vienna, Institute for Experimental Physics
cloud Bulgaria:
Institute for Nuclear Research and Nuclear Energy, Sofia
Estonia:
University of Tartu, Department of Environmental Physics
• 19 institutes from Europe, Finland:
Helsinki Institute of Physics and University of Helsinki, Department of Physics
Russia and USA Finnish Meteorological Institute, Helsinki
•
University of Kuopio, Department of Physics
14 atmospheric institutes Tampere University of Technology, Department of Physics
+ 5 space/CR/particle physics Germany:
•
Goethe-University of Frankfurt, Institute for Atmospheric and Environmental Sciences
CLOUD-ITN network of 10 Leibniz Institute for Tropospheric Research, Leipzig
Marie Curie fellows: 8 PhD Portugal:
University of Lisbon, Department of Physics
students + 2 postdocs
Russia:
Lebedev Physical Institute, Solar and Cosmic Ray Research Laboratory, Moscow
Switzerland:
CERN, Physics Department
Fachhochschule Nordwestschweiz (FHNW), Institute of Aerosol and Sensor Technology, Brugg
Paul Scherrer Institute, Laboratory of Atmospheric Chemistry
United Kingdom:
University of Leeds, School of Earth and Environment
University of Reading, Department of Meteorology
Rutherford Appleton Laboratory, Space Science Department
United States:
California Institute of Technology, Division of Chemistry and Chemical Engineering
35

36. Cloud observational scales
observational scale
1 nm 1 µm 1 mm 1m 1 km 1000 km
satellite
CLOUD ground/aircraft
cloud system
cloud scale
laboratory
microphysical scale
molecule CCN raindrop cloud parcel
/ion critical cloud droplet
cluster /ice particle
36

37. CLOUD method
P. Minginette
• aerosol chamber +
state-of-the-art
analysing instruments
in CERN PS beamline
• laboratory expts. under
precisely controlled
conditions (T, trace
gases, aerosols, ions)
• study aerosol
nucleation & growth;
and cloud droplet & ice
particle microphysics -
with and without beam
37

38. CLOUD-06
liq.N2 liq.O2 air
dewar dewar mixing SO2
(500 l) (500 l) station
03 generator
ultrapure air system
humidifier electrostatic
precipitator
UV collimator +HV (0-20kV) 4kV
condensation particle
counter (CPC) battery
scanning mobility
particle sizer (SMPS)
2m aerosol chamber atmospheric ion
spectrometer(AIS)
sampling chemical ionisation mass
probes spectrometer (CIMS;H2SO4)
Gerdien condenser
field
cage
SO2, O3 analysers
HV electrode
T, P, UV, H20
measurements
-HV (0-20kV)
UV lamp
array (254nm)
beam hodoscope
3.5 GeV/c !+
• Beam tests of pilot CLOUD experiment at CERN PS in Oct/Nov 2006
• Aims:
‣ Technical input for CLOUD design
‣ First physics measurements (H2SO4 ion-induced nucleation)
38

39. Aerosol bursts
Kulmala et al:
Fiedler, Arnold, Kulmala et al, ACP 2005 (Hyytiälä, Finland)
H2SO4 vapour aerosol no.
concentration concentration
(3-6 nm diameter)
2000 /cm3
0.1 pptv
H2SO4
90 min
delay
CLOUD-06 measurements:
• Bursts of aerosol particle
production growing to CCN
size in few hours observed
log(dN/dlog(Dp) [cm ])
AIS (-)
Mobility diameter [nm]
10 3.5
3.0
2.5
throughout troposphere
•
1
Associated with H2S04
2.0
AIS (+) 1.5
10 1.0
-3
production, but at very low
1 concentrations
•
10000 CPC threshold
Conc. [cm ]
Not yet understood:
-3
8000 3 nm
6000 3 nm
‣ Extra vapours (NH3,VOC)?
4000 5 nm
2000 7 nm
0 9 nm
0 2 4 6
Time [hr]
8 10 12 ‣ Ion-induced nucleation?
39

40. Beam intensity
CLOUD-06 results
200
run 35
[kHz]
100
0 0
8 10
7 3
Nucleation rate, J3 [cm s ]
5 6
-1
CPC threshold [nm]
4 3
Particle concentration [cm-3]
-1
6000 10
-3
2 3 SO2 [ppb]
5000 -2 0.3-0.6
1 5 10
4000 1.5
7 6
-3
3000 10
2000 9 -4
10
1000
-5
0 10
-8 -4 0 4 8 0 50 100 150 200 250
Time [h]
Beam intensity [kHz]
• Results of pilot CLOUD run:
‣ validated the basic experimental concept of CLOUD
‣ suggestive evidence for ion-induced nucleation of H2SO4-H2O under
atmospheric conditions
‣ provided important technical input for CLOUD design
40

41. CLOUD-09 design requirements
• Large chamber:
‣ Diffusion lifetime of aerosols/trace gases to walls ~L2
‣ Dilution lifetime of makeup gases ~L3
=> 3m chamber has typically 5-10 hr lifetimes
• Ultra-clean conditions:
‣ Condensable vapours, eg. [H2SO4] ~0.1 pptv
‣ Ultrapure air supply from cryogenic liquids
‣ UHV procedures for inner surfaces, no plastics 50 100
• Temperature stability and wide T range 40 80
CPC 3010 [# cm ]
-3
CPC 3025 [# cm ]
3 nm CPC 3025
30 7 nm CPC 3010 60
‣ 0.1oC stability 20 40
‣ Fibre-optic UV system for photochemistry
-3
10 20
‣ -90C → +100C range 0 0
Temperature [°C]
27
• Field cage up to 30 kV/m: 26
‣ Zero residual field
25
40 1.2
SO2 [ppb]
• O3 [ppb]
30
0.8
Particle beam 20 40
RH [%]
0.4
10 20
0 0.0 0
‣ Wide beam for ~uniform exposure 0 4 8 12
Time [hrs]
Time [hrs]
16 20 24
• Comprehensive analysers (measure “everything”, as for collider detectors...)
‣ Mass spectrometers for H2SO4, organics, aerosol composition
41

42. CLOUD-09 chamber at CERN
P. Minginette
42

43. CLOUD plans
• 2009:
‣ commission CLOUD-09
‣ study H2SO4-H2O nucleation with and without beam
‣ reproducibility of nucleation events
‣ PTR-Mass Spect. to measure organics at 10 pptv level
‣ new ion-TOF Mass Spect. for ion characterisation
• 2010:
‣ commission thermal system (-90C → +100C)
‣ study H2SO4/water + volatile organic compounds with
and without beam
‣ temperature dependence (effect of altitude)
• 2011-2013:
‣ extend studies to other trace vapours, and to cloud
droplets & ice particles (adiabatic expansions in chamber)
43

44. Conclusions
• Climate has continually varied in the past, and the causes are
not well understood - especially on the 100 year timescale
relevant for today’s climate change
• Strong evidence for solar-climate variability, but no established
mechanism. A cosmic ray influence on clouds is a leading
candidate
• CLOUD at CERN aims to study and quantify the cosmic ray-
cloud mechanism in a controlled laboratory experiment
• The question of whether - and to what extent - the climate is
influenced by solar/cosmic ray variability remains central to
our understanding of anthropogenic climate change
44