Aerosol nucleation over oceans and the role of galactic cosmic rays

Abstract. We investigate formation of sulfate aerosol in the marine troposphere from neutral and charged nucleation of H2SO4 and H2O. A box model of neutral and charged aerosol processes is run on a grid covering the oceans. Input data are taken from a model of galactic cosmic rays in the atmosphere, and from global chemistry and transport models. We find a weak aerosol production over the tropical oceans in the lower and middle troposphere, and a stronger production at higher latitudes, most notably downwind of industrial regions. The highest aerosol production, however, occurs in the upper troposphere, in particular in the tropics. This finding supports the proposition by which non-sea salt marine boundary layer aerosol in tropical regions does not form in situ, but nucleates in the upper troposphere from convectively lifted and cloud processed boundary layer air rich in aerosol precursor gases, from where it descends in subsiding air masses compensating convection. Convection of boundary layer air also appears to drive the formation of condensation nuclei in the tropical upper troposphere which maintains the stratospheric aerosol layer in the absence of volcanic activity. Neutral nucleation contributes only marginally to aerosol production in our simulations. This highlights the importance of charged binary and of ternary nucleation involving ammonia for aerosol formation. In clean marine regions however, ammonia concentrations seem too low to support ternary nucleation, making binary nucleation from ions a likely pathway for sulfate aerosol formation. On the other hand, our analysis indicates that the variation of ionization by galactic cosmic rays over the decadal solar cycle does not entail a response in aerosol production and cloud cover via the second indirect aerosol effect that would explain observed variations in global cloud cover. We estimate that the variation in radiative forcing resulting from a response of clouds to the change in galactic cosmic ray ionization and subsequent aerosol production over the decadal solar cycle is smaller than the concurrent variation of total solar irradiance.

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Aerosol nucleation over oceans and the role of galactic cosmic rays

Atmospheric Chemistry and Physics ◽

10.5194/acp-6-4905-2006 ◽

2006 ◽

Vol 6 (12) ◽

pp. 4905-4924 ◽

Cited By ~ 69

Author(s):

J. Kazil ◽

E. R. Lovejoy ◽

M. C. Barth ◽

K. O'Brien

Keyword(s):

Boundary Layer ◽

Solar Cycle ◽

Cosmic Rays ◽

Radiative Forcing ◽

Cloud Cover ◽

Cosmic Ray ◽

Galactic Cosmic Rays ◽

Aerosol Layer ◽

Aerosol Formation ◽

Upper Troposphere

Abstract. We investigate formation of sulfate aerosol in the marine troposphere from neutral and charged nucleation of H2SO4 and H2O. A box model of neutral and charged aerosol processes is run on a grid covering the oceans. Input data are taken from a model of galactic cosmic rays in the atmosphere, and from global chemistry and transport models. We find a weak aerosol production over the tropical oceans in the lower and middle troposphere, and a stronger production at higher latitudes, most notably downwind of industrial regions. The strongest aerosol production however occurs in the upper troposphere over areas with frequent convective activity, in particular in the tropics. This finding supports the proposition by which non-sea salt marine boundary layer aerosol in tropical regions does not form in situ, but nucleates in the upper troposphere from convectively lifted and cloud processed boundary layer air rich in aerosol precursor gases, from where it descends in subsiding air masses compensating convection. Convection of boundary layer air also appears to drive the formation of condensation nuclei in the tropical upper troposphere which maintains the stratospheric aerosol layer in the absence of volcanic activity. Neutral nucleation contributes only marginally to aerosol production in our simulations. This highlights the importance of other mechanisms, including charged binary and ternary, and neutral ternary nucleation for aerosol formation. Our analysis indicates that the variation of ionization by galactic cosmic rays over the decadal solar cycle does not entail a response in aerosol production and cloud cover via the second indirect aerosol effect that would explain observed variations in global cloud cover. We estimate that the variation in radiative forcing resulting from a response of clouds to the change in galactic cosmic ray ionization and subsequent aerosol production over the decadal solar cycle is smaller than the concurrent variation of total solar irradiance.

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Atmospheric data over a solar cycle: no connection between galactic cosmic rays and new particle formation

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-9-21525-2009 ◽

2009 ◽

Vol 9 (5) ◽

pp. 21525-21560 ◽

Cited By ~ 4

Author(s):

M. Kulmala ◽

I. Riipinen ◽

T. Nieminen ◽

M. Hulkkonen ◽

L. Sogacheva ◽

...

Keyword(s):

Solar Cycle ◽

Cosmic Rays ◽

Atmospheric Aerosol ◽

Cosmic Ray ◽

Particle Formation ◽

Galactic Cosmic Rays ◽

Minor Role ◽

New Particle Formation ◽

Aerosol Formation ◽

Radiative Balance

Abstract. Aerosol particles affect the Earth's radiative balance by directly scattering and absorbing solar radiation and, indirectly, through their activation into cloud droplets. Both effects are known with considerable uncertainty only, and translate into even bigger uncertainties in future climate predictions. More than a decade ago, variations in galactic cosmic rays were suggested to closely correlate with variations in atmospheric cloud cover and therefore constitute a driving force behind aerosol-cloud-climate interactions. Later, the enhancement of atmospheric aerosol particle formation by ions generated from cosmic rays was proposed as a physical mechanism explaining this correlation. Here, we report unique observations on atmospheric aerosol formation based on measurements at the SMEAR II station, Finland, over a solar cycle (years 1996–2008) that shed new light on these presumed relationships. Our analysis shows that none of the quantities related to aerosol formation correlates with the cosmic ray-induced ionisation intensity (CRII). We also examined the contribution of ions to new particle formation on the basis of novel ground-based and airborne observations. A consistent result is that ion-induced formation contributes typically less than 10% to the number of new particles, which would explain the missing correlation between CRII and aerosol formation. Our main conclusion is that galactic cosmic rays appear to play a minor role for atmospheric aerosol formation, and so for the connected aerosol-climate effects as well.

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Atmospheric data over a solar cycle: no connection between galactic cosmic rays and new particle formation

Atmospheric Chemistry and Physics ◽

10.5194/acp-10-1885-2010 ◽

2010 ◽

Vol 10 (4) ◽

pp. 1885-1898 ◽

Cited By ~ 67

Author(s):

M. Kulmala ◽

I. Riipinen ◽

T. Nieminen ◽

M. Hulkkonen ◽

L. Sogacheva ◽

...

Keyword(s):

Solar Cycle ◽

Cosmic Rays ◽

Atmospheric Aerosol ◽

Cosmic Ray ◽

Particle Formation ◽

Galactic Cosmic Rays ◽

Minor Role ◽

New Particle Formation ◽

Aerosol Formation ◽

Radiative Balance

Abstract. Aerosol particles affect the Earth's radiative balance by directly scattering and absorbing solar radiation and, indirectly, through their activation into cloud droplets. Both effects are known with considerable uncertainty only, and translate into even bigger uncertainties in future climate predictions. More than a decade ago, variations in galactic cosmic rays were suggested to closely correlate with variations in atmospheric cloud cover and therefore constitute a driving force behind aerosol-cloud-climate interactions. Later, the enhancement of atmospheric aerosol particle formation by ions generated from cosmic rays was proposed as a physical mechanism explaining this correlation. Here, we report unique observations on atmospheric aerosol formation based on measurements at the SMEAR II station, Finland, over a solar cycle (years 1996–2008) that shed new light on these presumed relationships. Our analysis shows that none of the quantities related to aerosol formation correlates with the cosmic ray-induced ionisation intensity (CRII). We also examined the contribution of ions to new particle formation on the basis of novel ground-based and airborne observations. A consistent result is that ion-induced formation contributes typically significantly less than 10% to the number of new particles, which would explain the missing correlation between CRII and aerosol formation. Our main conclusion is that galactic cosmic rays appear to play a minor role for atmospheric aerosol formation events, and so for the connected aerosol-climate effects as well.

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Cosmic ray spectra in planetary atmospheres

Proceedings of the International Astronomical Union ◽

10.1017/s1743921309029718 ◽

2008 ◽

Vol 4 (S257) ◽

pp. 471-473

Author(s):

M. Buchvarova ◽

P. Velinov

Keyword(s):

Experimental Data ◽

Solar Cycle ◽

Cosmic Rays ◽

Cosmic Ray ◽

Planetary Atmospheres ◽

Galactic Cosmic Rays ◽

Outer Planets ◽

Practical Possibility ◽

The Earth ◽

Theoretical Results

AbstractOur model generalizes the differential D(E) and integral D(>E) spectra of cosmic rays (CR) during the 11-year solar cycle. The empirical model takes into account galactic (GCR) and anomalous cosmic rays (ACR) heliospheric modulation by four coefficients. The calculated integral spectra in the outer planets are on the basis of mean gradients: for GCR – 3%/AU and 7%/AU for anomalous protons. The obtained integral proton spectra are compared with experimental data, the CRÈME96 model for the Earth and theoretical results of 2D stochastic model. The proposed analytical model gives practical possibility for investigation of experimental data from measurements of galactic cosmic rays and their anomalous component.

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Atmospheric changes caused by galactic cosmic rays over the period 1960–2010

Atmospheric Chemistry and Physics ◽

10.5194/acp-16-5853-2016 ◽

2016 ◽

Vol 16 (9) ◽

pp. 5853-5866 ◽

Cited By ~ 17

Author(s):

Charles H. Jackman ◽

Daniel R. Marsh ◽

Douglas E. Kinnison ◽

Christopher J. Mertens ◽

Eric L. Fleming

Keyword(s):

Cosmic Rays ◽

Climate Model ◽

Cosmic Ray ◽

Galactic Cosmic Rays ◽

Sulfate Aerosol ◽

Solar Cycle Variation ◽

Aerosol Loading ◽

Ion Production ◽

Column Ozone ◽

The Impact

Abstract. The Specified Dynamics version of the Whole Atmosphere Community Climate Model (SD-WACCM) and the Goddard Space Flight Center two-dimensional (GSFC 2-D) models are used to investigate the effect of galactic cosmic rays (GCRs) on the atmosphere over the 1960–2010 time period. The Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) computation of the GCR-caused ionization rates are used in these simulations. GCR-caused maximum NOx increases of 4–15 % are computed in the Southern polar troposphere with associated ozone increases of 1–2 %. NOx increases of ∼ 1–6 % are calculated for the lower stratosphere with associated ozone decreases of 0.2–1 %. The primary impact of GCRs on ozone was due to their production of NOx. The impact of GCRs varies with the atmospheric chlorine loading, sulfate aerosol loading, and solar cycle variation. Because of the interference between the NOx and ClOx ozone loss cycles (e.g., the ClO + NO2+ M  →  ClONO2+ M reaction) and the change in the importance of ClOx in the ozone budget, GCRs cause larger atmospheric impacts with less chlorine loading. GCRs also cause larger atmospheric impacts with less sulfate aerosol loading and for years closer to solar minimum. GCR-caused decreases of annual average global total ozone (AAGTO) were computed to be 0.2 % or less with GCR-caused column ozone increases between 1000 and 100 hPa of 0.08 % or less and GCR-caused column ozone decreases between 100 and 1 hPa of 0.23 % or less. Although these computed ozone impacts are small, GCRs provide a natural influence on ozone and need to be quantified over long time periods. This result serves as a lower limit because of the use of the ionization model NAIRAS/HZETRN which underestimates the ion production by neglecting electromagnetic and muon branches of the cosmic ray induced cascade. This will be corrected in future works.

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Variations in Radiocarbon Production in the Earth's Atmosphere

Radiocarbon ◽

10.1017/s0033822200009425 ◽

1980 ◽

Vol 22 (2) ◽

pp. 159-165 ◽

Cited By ~ 12

Author(s):

Serge A Korff ◽

Rosalind B Mendell

Keyword(s):

Solar Wind ◽

Solar Cycle ◽

Cosmic Rays ◽

Magnetic Fields ◽

Solar Flare ◽

Production Rate ◽

Sunspot Number ◽

Cosmic Ray ◽

Galactic Cosmic Rays ◽

Solar Particle Events

We have investigated solar phenomena associated with unusual changes in the production rates of 14C in the atmosphere. 14C is produced in interactions of cosmic ray neutrons with nitrogen in the atmosphere. Intensity of the neutrons varies globally and fluctuates with time as a result of interactions of galactic cosmic rays which generate neutrons with plasma and magnetic fields of the solar wind. We estimate the total mean production rate of 14C for solar cycle 20, specifically 1965 to 1975, to be 2.25 ± 0.1 nuclei-cm−2sec−1 from galactic cosmic rays alone, with negligible integrated contribution from solar particle events. Annual averages of Rz, the Zurich sunspot number, and the production rate of 14C, n(14C), were related by n(14C) = 2.60–5.53 × 10–3 Rz ± 3 percent. The contribution of solar flare particles and the zero sunspot limit are discussed with relation to major fluctuations that appear in the radiocarbon versus dendrochronology over short (∼100 years) integration times.

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Cosmic rays, CCN and clouds – a reassessment using MODIS data

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-8-13265-2008 ◽

2008 ◽

Vol 8 (4) ◽

pp. 13265-13299 ◽

Cited By ~ 7

Author(s):

J. E. Kristjánsson ◽

C. W. Stjern ◽

F. Stordal ◽

A. M. Fjǽraa ◽

G. Myhre ◽

...

Keyword(s):

Cosmic Rays ◽

Optical Depth ◽

Cloud Cover ◽

Forbush Decrease ◽

Cloud Droplet ◽

Cosmic Ray ◽

Galactic Cosmic Rays ◽

Modis Data ◽

Low Clouds ◽

Cloud Water Content

Abstract. The response of clouds to sudden decreases in the flux of galactic cosmic rays (Forbush decrease events) has been investigated using cloud products from the space-borne MODIS instrument, which has been in operation since 2000. By focusing on pristine Southern Hemisphere ocean regions we examine areas which are particularly susceptible to changes in cloud condensation nuclei (CCN) concentrations, and where a cosmic ray signal should be easier to detect than elsewhere. While previous studies on the subject have mainly considered cloud cover, the high spatial and spectral resolution of MODIS allows for a more thorough study of microphysical parameters such as cloud droplet size, cloud water content and cloud optical depth, in addition to cloud cover. Averaging the results from the 13 Forbush decrease events that were considered, no systematic correlation was found between any of the four cloud parameters and galactic cosmic radiation, with a seemingly random distribution of positive and negative correlations. When only the three Forbush decrease events with the largest amplitude are studied, the correlations fit the hypothesis better, with 8 out of 12 correlations having the expected sign. Splitting the area of study into several sub-regions, one sub-region in the Atlantic Ocean showed statistically significant correlations compatible with a cosmic ray-induced enhancement of CCN and cloud droplet number concentrations. However, the lack of correlation in any of the other 5 sub-regions suggests that this may be a statistical co-incidence. Introducing a time lag of a few days for clouds to respond to the cosmic ray signal did not change the overall results. Singling out low clouds of intermediate optical depth with large susceptibility did not lead to higher correlations. In conclusion, no response to variations in cosmic rays associated with Forbush decrease events was found in marine low clouds in remote regions using MODIS data.

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LOW ENERGY SOLAR AND GALACTIC COSMIC RAYS AT 1 AU

International Journal of Modern Physics A ◽

10.1142/s0217751x02011187 ◽

2002 ◽

Vol 17 (12n13) ◽

pp. 1685-1694

Author(s):

MARCO CASOLINO

Keyword(s):

Solar Cycle ◽

Cosmic Rays ◽

Energetic Particle ◽

Space Station ◽

Solar Energetic Particle ◽

Cosmic Ray ◽

Galactic Cosmic Rays ◽

Low Energy ◽

Solar Energetic Particle Events ◽

Satellite Missions

In this work we present some of the recent results obtained with the satellite missions NINA-1 and NINA-2 and the experiments on board MIR space station Sileye-1 and 2. The aim is the study of the low energy (10 MeV - 2 GeV) cosmic ray component and different periods of the solar cycle and during Solar Energetic Particle events. Other items of physics include the measurement of the secondary cosmic ray component, produced in the interaction with the upper layers of Earth's atmosphere and the evaluation of the absorbed and equivalent doses inside MIR.

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Measurement of the cosmic ray proton spectrum from 40 GeV to 100 TeV with the DAMPE satellite

Science Advances ◽

10.1126/sciadv.aax3793 ◽

2019 ◽

Vol 5 (9) ◽

pp. eaax3793 ◽

Cited By ~ 16

Author(s):

◽

Q. An ◽

R. Asfandiyarov ◽

P. Azzarello ◽

P. Bernardini ◽

...

Keyword(s):

Cosmic Rays ◽

Cosmic Radiation ◽

Precise Measurement ◽

Milky Way ◽

Spectral Feature ◽

Dark Matter Particle ◽

Cosmic Ray ◽

Galactic Cosmic Rays ◽

Proton Spectrum ◽

First Time

The precise measurement of the spectrum of protons, the most abundant component of the cosmic radiation, is necessary to understand the source and acceleration of cosmic rays in the Milky Way. This work reports the measurement of the cosmic ray proton fluxes with kinetic energies from 40 GeV to 100 TeV, with 2 1/2 years of data recorded by the DArk Matter Particle Explorer (DAMPE). This is the first time that an experiment directly measures the cosmic ray protons up to ~100 TeV with high statistics. The measured spectrum confirms the spectral hardening at ~300 GeV found by previous experiments and reveals a softening at ~13.6 TeV, with the spectral index changing from ~2.60 to ~2.85. Our result suggests the existence of a new spectral feature of cosmic rays at energies lower than the so-called knee and sheds new light on the origin of Galactic cosmic rays.

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Atmospheric production and transport of 7Be activity by cosmic rays: Modelling with the chemistry-climate model SOCOLv3.0 and comparison with direct measurements

10.5194/egusphere-egu21-2287 ◽

2021 ◽

Author(s):

Kseniia Golubenko ◽

Eugene Rozanov ◽

Genady Kovaltsov ◽

Ari-Pekka Leppänen ◽

Ilya Usoskin

Keyword(s):

Cosmic Rays ◽

Climate Changes ◽

Climate Model ◽

Cosmic Ray ◽

Galactic Cosmic Rays ◽

Cosmogenic Isotopes ◽

Cosmogenic Isotope ◽

The Past ◽

Direct Measurements ◽

First Results

We present the first results of modelling of the short-living cosmogenic isotope 7Be production, deposition, and transport using the chemistry-climate model SOCOLv3.0 aimed to study solar-terrestrial interactions and climate changes. We implemented an interactive deposition scheme, &#160;based on gas tracers with and without nudging to the known meteorological fields. Production of 7Be was modelled using the 3D time-dependent Cosmic Ray induced Atmospheric Cascade (CRAC) model. The simulations were compared with the real concentrations (activity) and depositions measurements of 7Be in the air and water at Finnish stations. We have successfully reproduced and estimated the variability of the cosmogenic isotope 7Be produced by the galactic cosmic rays (GCR) on time scales longer than about a month, for the period of 2002&#8211;2008. The agreement between the modelled and measured data is very good (within 12%) providing a solid validation for the ability of the SOCOL CCM to reliably model production, transport, and deposition of cosmogenic isotopes, which is needed for precise studies of cosmic-ray variability in the past.&#160;

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