Galactic Cosmic Ray Modulation at Mars and beyond measured with EDACs on Mars Express and Rosetta

Galactic Cosmic Rays (GCRs) are an intrinsic part of the heliospheric radiation environment, and an inevitable challenge to long-term space exploration. Here we show solar cycle induced GCR modulation at Mars in the period 2005-2020, along with GCR radial gradients, by utilising Mars Express and Rosetta engineering parameters compared to sunspot number time series. The engineering parameter used is called EDAC (Error Detection And Correction), a cumulative counter which is triggered by charged energetic particle causing memory errors in on-board computers. EDAC data provides a new way of gaining insight&#160;into the field of particle transport in the heliosphere, allowing us to circumvent&#160;the need for dedicated instrumentation as EDAC software is present on all spacecraft.This data set can be used to capture variations of GCRs in both space and time, yielding the same qualitative information as ground-based neutron monitors. Our analysis of the Mars Express EDAC parameter reveals a strong solar cycle GCR modulation, yielding an anticorrelation coefficient of -0.5 at a time lag of ~5.5 months. By combining Mars Express with Rosetta data, we calculate a 5.3% increase in EDAC count rates per astronomical unit, attributed to a radial gradient in GCR fluxes in accordance with established literature.The potential of engineering data for scientific purposes remains mostly unexplored. The results obtained from this work demonstrates, for the first time for heliophysics purposes, the usefulness of the EDAC engineering parameter, data mining and the utility of keeping missions operational for many years, providing complimentary data to nominal science instruments.

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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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Aerosol nucleation over oceans and the role of galactic cosmic rays

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-6-5543-2006 ◽

2006 ◽

Vol 6 (3) ◽

pp. 5543-5583 ◽

Cited By ~ 1

Author(s):

J. Kazil ◽

E. R. Lovejoy ◽

M. C. Barth ◽

K. O’Brien

Keyword(s):

Boundary Layer ◽

Solar Cycle ◽

Cosmic Rays ◽

Cloud Cover ◽

Cosmic Ray ◽

Galactic Cosmic Rays ◽

Sulfate Aerosol ◽

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 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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The Radiation Environment on the Surface of Mars: dMEREM predictions based on RAD data

10.5194/epsc2021-411 ◽

2021 ◽

Author(s):

Patrícia Gonçalves ◽

Luisa Arruda ◽

Marco Pinto

Keyword(s):

Radiation Field ◽

Solar Energetic Particle ◽

Cosmic Ray ◽

High Energy ◽

Galactic Cosmic Rays ◽

Field Of View ◽

Radiation Environment ◽

Soil Composition ◽

Particle Radiation ◽

Spectrometer Data

The characterisation of the Martian radiation environment is essential to understand if the planet can sustain life and ultimately if its human exploration is feasible. The major components of the radiation environment in the Mars orbit, are Galactic Cosmic Rays (GCRs) and Solar Energetic Particle (SEP) events. Since Mars has a negligible magnetic field and a much thinner atmosphere compared to the Earth&#8217;s, its surface is exposed to GCR and eventual SEP events, as well as to secondary particles produced in the atmosphere and in the shallow layers of the planet. The Curiosity rover that has been exploring the surface of Mars since August 2012, carries in its Mars Science Laboratory (MSL), the Radiation Assessment Detector (RAD) which measures high-energy radiation, such as protons, energetic ions of various elements, neutrons, and gamma rays. That includes not only direct radiation from space, but also secondary radiation produced by the interaction of space radiation with the atmosphere and surface rocks and soil. The detailed Martian Energetic Radiation Environment Model (dMEREM) is a GEometry ANd Tracking (GEANT4) based model developed for ESA which enables to predict the radiation environment expected at different locations on the Martian orbit, atmosphere and surface, as a function of epoch, latitude and longitude, taking into account the specific atmospheric and soil composition. dMEREM can be interfaced to different Primary Particle Models, such as the ISO-15390 and the Badhwar - O'Neill (BON) 2014 or 2020 Galactic Cosmic Ray Flux Models, or the National Aeronautics and Space Administration (NASA) Emission of Solar Protons (ESP) model for solar energetic proton fluences. dMEREM is interfaced with the European Mars Climate Database from where it retrieves information on the atmosphere composition and density at specific locations and solar longitudes and Gamma Ray Spectrometer data aboard Mars Odyssey, for the description of Mars soil composition, although soil compositions for specific locations, including those locally sampled by Martian rovers can also be defined by the user. dMEREM provides the kinetic energy and directional spectra of all particle types produced in the interactions of energetic particles with the Martian Atmosphere and Soil. The dMEREM validation results using differential proton fluxes stopping in the RAD sensor head as measured by MSL/RAD in Gale crater from November 15, 2015 to January 15, 2016 and in the begin of September 2017 is presented. Although the RAD only measures a limited field-of-view in zenith angle of the Martian Particle Radiation Field, the good agreement between the RAD data and the dMEREM predictions for protons within the RAD field of-view, are used as the basis for the use of dMEREM in the assessment of the expected ionizing radiation field on the surface of Mars for particles coming from all directions, including albedo particles. This assessment is also used to make predictions of dosimetric quantities, such as Ambient Dose Equivalent and Effective Dose, relevant for Human Space Flight, for the considered data periods. &#160;

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Long-term modulation of the cosmic ray fluctuation spectrum

Annales Geophysicae ◽

10.5194/angeo-24-779-2006 ◽

2006 ◽

Vol 24 (2) ◽

pp. 779-783 ◽

Cited By ~ 5

Author(s):

S. A. Starodubtsev ◽

I. G. Usoskin ◽

A. V. Grigoryev ◽

K. Mursula

Keyword(s):

Solar Cycle ◽

Lower Energy ◽

Power Level ◽

Cosmic Ray ◽

Galactic Cosmic Rays ◽

Frequency Range ◽

Fluctuation Spectrum ◽

Near Earth Space ◽

Energy Channels

Abstract. Here we study the power level of rapid cosmic ray fluctuations in the frequency range of 10-4-1.67·10-3 Hz (periods from 10 min to about 3 h), using measurements by space-borne instruments for the period since 1974. We find that the power level of these fluctuations varies over the solar cycle, but the phase of this variation depends on the energy of cosmic ray particles. While the power level of these fluctuations in the higher energy channels (corresponding to galactic cosmic rays) changes in phase with the solar cycle, the fluctuation level for lower energy channels (predominantly of solar/interplanetary origin) is roughly in an opposite phase with the solar cycle. The results prove conclusively that these fluctuations originate in the near-Earth space, excluding their atmospheric or magnetospheric origin. We present these new results and discuss a possible scenario explaining the observed energy-dependence.

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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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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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Multi-point galactic cosmic ray measurements between 1 and 4.5 AU over a full solar cycle

Annales Geophysicae ◽

10.5194/angeo-37-903-2019 ◽

2019 ◽

Vol 37 (5) ◽

pp. 903-918 ◽

Cited By ~ 1

Author(s):

Thomas Honig ◽

Olivier G. Witasse ◽

Hugh Evans ◽

Petteri Nieminen ◽

Erik Kuulkers ◽

...

Keyword(s):

Gamma Ray ◽

Cosmic Ray ◽

High Energy ◽

Galactic Cosmic Rays ◽

Radiation Environment ◽

Radiation Data ◽

Rosetta Mission ◽

The Stability ◽

Cross Calibration ◽

Galactic Cosmic Ray

Abstract. The radiation data collected by the Standard Radiation Environment Monitor (SREM) aboard ESA missions INTEGRAL (INTErnational Gamma-Ray Astrophysics Laboratory), Rosetta, Herschel, Planck and Proba-1, and by the high-energy neutron detector (HEND) instrument aboard Mars Odyssey, are analysed with an emphasis on characterising galactic cosmic rays (GCRs) in the inner heliosphere. A cross calibration between all sensors was performed for this study, which can also be used in subsequent works. We investigate the stability of the SREM detectors over long-term periods. The radiation data are compared qualitatively and quantitatively with the corresponding solar activity. Based on INTEGRAL and Rosetta SREM data, a GCR helioradial gradient of 2.96 % AU−1 is found between 1 and 4.5 AU. In addition, the data during the last phase of the Rosetta mission around comet 67P/Churyumov–Gerasimenko were studied in more detail. An unexpected yet unexplained 8 % reduction of the Galactic Comic Ray flux measured by Rosetta SREM in the vicinity of the comet is noted.

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Features of the Galactic Cosmic Ray Anisotropy in Solar Cycle 24 and Solar Minima 23/24 and 24/25

Solar Physics ◽

10.1007/s11207-019-1540-5 ◽

2019 ◽

Vol 294 (10) ◽

Author(s):

R. Modzelewska ◽

K. Iskra ◽

W. Wozniak ◽

M. Siluszyk ◽

M. V. Alania

Keyword(s):

Magnetic Field ◽

Solar Cycle ◽

Solar Minimum ◽

Cosmic Ray ◽

Radial Component ◽

Galactic Cosmic Rays ◽

Positive Polarity ◽

Heliospheric Magnetic Field ◽

Solar Cycle 24 ◽

Cycle 24

Abstract We study the role of the drift effect in the temporal changes of the anisotropy of galactic cosmic rays (GCRs) and the influence of the sector structure of the heliospheric magnetic field on it. We analyze the GCR anisotropy in Solar Cycle 24 and solar minimum 23/24 with negative polarity ($qA<0$qA<0) for the period of 2007 – 2009 and near minimum 24/25 with positive polarity ($qA>0$qA>0) in 2017 – 2018 using data of the global network of Neutron Monitors. We use the harmonic analysis method to calculate the radial and tangential components of the anisotropy of GCRs for different sectors (‘+’ corresponds to the positive and ‘−’ to the negative directions) of the heliospheric magnetic field. We compare the analysis of GCR anisotropy using different evaluations of the mean GCRs rigidity related to Neutron Monitor observations. Then the radial and tangential components are used for characterizing the GCR modulation in the heliosphere. We show that in the solar minimum 23/24 in 2007 – 2009 when $qA<0$qA<0, the drift effect is not visibly evident in the changes of the radial component, i.e. the drift effect is found to produce $\approx 4$≈4% change in the radial component of the GCR anisotropy for 2007 – 2009. Hence the diffusion dominated model of GCR transport is more acceptable in 2007 – 2009. In turn, near the solar minimum 24/25 in 2017 – 2018 when $qA>0$qA>0, the drift effect is evidently visible and produces ≈40% change in the radial component of the GCR anisotropy for 2017 – 2018. So in the period of 2017 – 2018 a diffusion model with noticeably manifested drift is acceptable. The results of this work are in good agreement with the drift theory of GCR modulation, according to which, during negative (positive) polarity cycles, a drift stream of GCRs is directed toward (away from) the Sun, thus giving rise to a 22-year cycle variation of the radial GCR anisotropy.

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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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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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