Cosmic rays and processes in the atmosphere

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Cosmic rays and processes in the atmosphere

• Yuri Stozhkov
• P.N. Lebedev Physical Institute, Russian academy
  of sciences

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ContentIntroductionCR in the
atmosphereIonization in the atmosphereAtmospheri
c electricityCR fluxes and atmospheric
processesCR fluxes, Be-10 and C-14 atomsAbout
global warming in futureConclusion
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ContentIntroductionCR in the
atmosphereIonization in the atmosphereAtmospheri
c electricityCR fluxes and atmospheric
processesCR fluxes, Be-10 and C-14 atomsAbout
global warming in futureConclusion
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Energy fluxesSolar irradiation
? 1.36 103 W/m2 Galactic cosmic rays
(particles with ? gt 0.1 GeV)
? 10-5 W/m2
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CR fluxes define general electric properties of
the atmosphere and govern electric processes in
it. Now we understand the main physical
mechanisms being at the basis of such phenomena
as global electric circuit operation,
thunderstorm formation, lightning production and
so on.
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Sprites and elves triggered by the
ground-to-cloud lightning (Lyons W.A., et al.,
2000, EOS, v. 81, 373).
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ContentIntroductionCR in the
atmosphereIonization in the atmosphereAtmospheri
c electricityCR fluxes and atmospheric
processesCR fluxes, Be-10 and C-14 atomsAbout
global warming in futureConclusion
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Green curve - cosmic ray flux (monthly data) at
Pfotzers maximum at polar region (Rc0.6 GV).
Red curve - cosmic ray flux data smoothed with
T22 years.Blue line calculation with a least
square method
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Particle precipitation
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ContentIntroductionCR in the
atmosphereIonization in the atmosphereAtmospheri
c electricityCR fluxes and atmospheric
processesCR fluxes, Be-10 and C-14 atomsAbout
global warming in futureConclusion
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ContentIntroductionCR in the
atmosphereIonization in the atmosphereAtmospheri
c electricityCR fluxes and atmospheric
processesCR fluxes, Be-10 and C-14 atomsAbout
global warming in futureConclusion
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Mesoscale Convective Systems
Mareev E.A., 2004 S. Davydenko et al., JGR, D5,
2004
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Electric characteristics of the atmosphere
Electric charge of the Earth Q ? - 600 000
C Electric field strength near the surface
E ? 130 V/m Electric current in the
atmosphere J ? 10-12 A/m2
Jtot ? 2000 A
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r (I, J) 0.67 ? 0.14 r (J, Rz) ?
0.32 ? 0.22
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GCR flux and lightning activity
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ContentIntroductionCR in the
atmosphereIonization in the atmosphereAtmospheri
c electricityCR fluxes and atmospheric
processesCR fluxes, Be-10 and C-14 atomsAbout
global warming in futureConclusion
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Relative changes of daily values of rainfall
before Forbush-decrease (negative days), during
the main phase of F-d (zero day), and after F-d
(positive days). Rainfall data were collected
from Brazil and USSR territories for the period
of 1956-1993. 70 Forbush-events were analyzed D
- (13.2?2.5) . For Brazil data only (15
Forbush-events) D - (29.2?7.5) .
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Relative changes of daily values of rainfall
before solar proton event (negative days), during
the solar proton event (zero day), and after it
(positive days). Rainfall data were collected
from Brazil and USSR territories for the period
of 1942-1993. 43 solar proton events (particles
with energy gt several GeV) were analyzed D
(13.3?5.3) . The superposed epoch method was
used.
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ContentIntroductionCR in the
atmosphereIonization in the atmosphereAtmospheri
c electricityCR fluxes and atmospheric
processesCR fluxes, Be-10 and C-14 atomsAbout
global warming in futureConclusion
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• In the atmosphere cosmic rays (CR) produce Be-10,
  
• C-14 and other radionuclides. It is commonly
• supposed that the concentrations of Be-10 in
  polar
• ice and C-14 in tree rings are good proxies of CR
• fluxes impinging on the top of the atmosphere.
• But before the precipitation on the Earths
  surface
• these elements spend several years in the
• atmosphere.
• The atmospheric processes play an essential role
  in
• the radionuclide precipitation and destroy the
• relationship between CR and radionuclide
  concentrations.

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Keplers Supernova Remnant
10-year averages of C-14 data over the period of
859 - 1900 Yearly Be-10 data from Greenland for
the period of 1423 - 1985 22-year smoothed Be-10
data from Antarctica over the period of 859 -
1973
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There is a large difference in the mean values of
Be-10 concentrations obtained from Greenland and
Antarctic ice cores. The ltBe-10gt concentrations
in Greenland and Antarctica calculated over
periods shown in the Figure are 1.05 and 3.86 (in
the units of 104 atoms/g) accordingly. The
correlation between Be-10 data from Greenland and
C-14 data is low. After exclusion of the trend in
C-14 dataset the maximum value of a correlation
coefficient was 0.49 with a time shift of 6
years.
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Correlation coefficient between Antarctic Be-10
data and C-14 data vs. time shift (C-14 ? Be-10).
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Table 1. The ratios of maximum cosmic ray fluxes
(CR) to minimum ones observed in the periods of
minimum and maximum solar activity and the ratios
of Be-10 concentrations during the same periods.
?t t(Be-10) t(CR) is the time shift between
Be-10 and cosmic ray data.
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The averaged amplitude of 11-solar cycle in Be-10
data from Greenland ice cores was found as
where
and
where the values of CRzmin and CRzmin are the
values of Be-10 concentrations during minima and
maxima of sunspot number periods accordingly.
Then the mean fractional ratio values ltAgt vs.
different time shifts between Be-10 and solar
activity data were calculated.
and
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The maximum mean value of ltAgt for Be-10 data
calculated over the period since 1711 till 1986
is 0.31 with a 4-year time shift. The mean
value of ltAgt for CR (particles with E gt 0.1 GeV),
calculated over the period since 1954 till 1981
is 2.44 ? 0.08. It means that the amplitude of
11-year modulation in CR is much bigger than in
Be-10 produced by CR. The facts given above
could be explained by the weather (climate
changes) influence.
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The different sets of data on radionuclides
produced by CRs are agreed with each other not so
well. The amplitude of variation in Be-10 data
is much lower than that of CR in the 11-year
solar cycle. The atmospheric effects play a main
role in the variations of Be-10 and C-14
concentration. It is better to use the
relationship of CR fluxes with sunspot number
(correlation coefficient is -0.9) to calculate
the CR fluxes in the past.
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References J. Beer, J., S. Tobias, and N. Weiss,
Solar Phys., 181, 237 (1998). J. Beer et. all,
The Sun as a Variable Star Solar and Stellar
Irradiance Variations (eds. J.M. Pap, C.
Frahlich, H.S. Hudson and S.K. Solanki),
Cambridge University Press, 291 (1994). M.
Stuiver, P. J. Reimer and T. F. Braziunas,
Radiocarbon, 40, 1127 (1998). Yu.I. Stozhkov,
V.P. Okhlopkov, N.S. Svirzhevsky, Solar Physics,
224, 323 (2004). I. Hansen et al., JGR, 104, No.
D24, 30,997 (1999).
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ContentIntroductionCR in the
atmosphereIonization in the atmosphereAtmospheri
c electricityCR fluxes and atmospheric
processesCR fluxes, Be-10 and C-14 atomsAbout
global warming in futureConclusion
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One of the main weather parameter is the average
temperature of the atmosphere surface layer.
The temperature data were reduced to the values
of dT ltdTgt - T. The time dependences of Be-10
and dT data and correlation between them are
shown below.
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The relationship between Be-10 concentration and
dT surface temperature data. The correlation
coefficient between these data is r 0.54. The
slope is 0.08 ? 104 Be-10 atoms/g per 1? C. In
relative values it is 7.6 per 1? C.
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The cosmic ray flux growth (decay) increases
(decreases) thunderstorm activity thundercloud
formation, lightning number. Kinetic energy of
one cyclone is ? 1018 J and lifetime is about one
week. A water amount in an average thundercloud
with the thunderstorm activity of ? 10
lightning/min is W ? 2?105 ton. In the process of
such thundercloud formation a hidden heat of Q
k ? W ? 5?1014 J is released into the atmosphere
(k 2.256?106 J/kg). The electric activity of an
average thundercloud is ? 30 min. Simultaneously
in the atmosphere there are ? 2000 thunderclouds.
So, the total number of thunderclouds arising
during the day equals to ? 105. They release into
the atmosphere ? 5?1019 J/day. The efficiency
factor of the heat machine of the Atmosphere
transforming the heat energy into the kinetic one
is ? 2. So, kinetic energy releasing in the
atmosphere in the process of thundercloud
formation is ? 1018 J/day. It is enough to
produce one average cyclone per day. It follows
that the essential changes of thunderstorm
activity will change the weather on the Earth.
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There is a following link solar activity
changes modulation of cosmic ray
flux cloud coverage and
thunderstorm activity changes
weather and climate changes
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Conclusion
(1) Cosmic ray particles play a very important
role in many atmospheric processes. They produce
atmospheric unlike electric charges, which
provide air conductivity and the operation of
global electric circuit. (2) Cosmic ray fluxes
take part in the cloud and thundercloud formation
process accelerating it and changing global cloud
coverage and thunderstorm activity. (3) The
change of cloud coverage and thunderstorm
activity influence the Earths survace
temperature. There is the following chain in
the solar-terrestrial-weather-climate
relationship solar activity changes
cosmic ray flux changes cosmic ray flux
changes cloud coverage and thunderstorm
activity changes cloud coverage and
thunderstorm activity changes global
temperature changes.
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• 1. Skryabin N.G., Sokolov V.D.,
• Novikov A.M. et al. (Yakutsk)
• 2. Veretennikova C., Dergachev V.A.,
• Pudovkin M.I., Raspopov O.M.,
• et al. (?-Pb)
• 3. Shumilov O.I., Vashenyik E.V.
• et al. (Apatity)