<scp>INCREASE</scp>: An updated model suite to study the <scp>INfluence</scp> of Cosmic Rays on Exoplanetary <scp>AtmoSpherEs</scp>

Herbst, K.; Grenfell, John Lee; Sinnhuber, Miriam; Wunderlich, Fabian

doi:10.1002/asna.20210072

Cited by 4 publications

(6 citation statements)

References 70 publications

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“…Thus, the GCR-induced Venusian absorbed dose rates at the top of the HZ, for example, are well below the magnitudes that can be found at flight altitudes at Earth. As has been pointed out by Dartnell et al (2015), even for the worst-case scenario of the GLE05-based AD774/775 spectrum, the induced absorbed radiation dose rates of about 33.9 mGy/h at the top of the habitable zone are in addition well below those of the impact of GLE05 on the terrestrial absorbed dose rate values (41.7 mGy/h, see Herbst et al 2019b). However, as has been pointed out by Dartnell et al (2015), even radiation-sensitive microorganisms, for example, Shewanella oneidensis, can survive much higher radiation dosages than those induced during this worst-case scenario.…”

Section: Total Absorbed Dose Rate Induced By Modern Strong Sep Eventsmentioning

confidence: 85%

“…In order to directly compare the Venusian radiation hazard on water-based life, we can compare our results to the absorbed dose rates measured at Earth. Here, the GCR-induced background leads to absorbed dose rates between 5×10 −4 mGy/h at the ground (∼ 1033 g/cm 2 , see, e.g., Banjac et al 2019b) and 0.3 mGy/h at flight altitudes where the dose rate maximum is located (∼ 120 g/cm 2 see, e.g., Herbst et al 2019b). Thus, the GCR-induced Venusian absorbed dose rates at the top of the HZ, for example, are well below the magnitudes that can be found at flight altitudes at Earth.…”

Section: Total Absorbed Dose Rate Induced By Modern Strong Sep Eventsmentioning

confidence: 99%

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Revisiting the cosmic-ray induced Venusian radiation dose in the context of habitability

Herbst

Banjac

Atri³

et al. 2019

A&A

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Context. Cosmic rays (CRs), which constantly bombard planetary magnetic fields and atmospheres, are the primary driver of atmospheric spallation processes. The higher the energy of these particles, the deeper they penetrate the planetary atmosphere, and the more likely interactions become with the ambient atmospheric material and the evolution of secondary particle showers. Aims. As recently discussed in the literature, CRs are the dominant driver of the Venusian atmospheric ionization and the induced radiation dose below ∼100 km. In this study, we model the atmospherically absorbed dose and the dose equivalent to the effect of cosmic rays in the context of Venusian habitability. Methods. The Atmospheric Radiation Interaction Simulator (AtRIS) was used to model the altitude-dependent Venusian absorbed dose and the Venusian dose equivalent. For the first time, we modeled the dose rates for different shape-, size-, and composition-mimicking detectors (phantoms): a CO 2 -based phantom, a water-based microbial cell, and a phantom mimicking human tissue. Results. Based on our new model approach, we give a reliable estimate of the altitude-dependent Venusian radiation dose in water-based microorganisms here for the first time. These microorganisms are representative of known terrestrial life. We also present a detailed analysis of the influence of the strongest ground-level enhancements measured at the Earth's surface, and of the impact of two historic extreme solar events on the Venusian radiation dose. Our study shows that because a phantom based on Venusian air was used, and because furthermore, the quality factors of different radiation types were not taken into account, previous model efforts have underestimated the radiation hazard for any putative Venusian cloud-based life by up to a factor of five. However, because we furthermore show that even the strongest events would not have had a hazardous effect on putative microorganisms within the potentially habitable zone (51 km -62 km), these differences may play only a minor role.

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Section: Total Absorbed Dose Rate Induced By Modern Strong Sep Eventsmentioning

confidence: 85%

Section: Total Absorbed Dose Rate Induced By Modern Strong Sep Eventsmentioning

confidence: 99%

Revisiting the cosmic-ray induced Venusian radiation dose in the context of habitability

Herbst

Banjac

Atri³

et al. 2019

A&A

Self Cite

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“…As a first step, Herbst et al (2019Herbst et al ( , 2022a) built up the model suite INCREASE, a simulation chain that couples the state-of-theart magnetospheric and atmospheric propagation and interaction models PLANETOCOSMICS (Desorgher et al 2006) and AtRIS (Banjac et al 2019) with the atmospheric chemistry and climate model 1D-TERRA (e.g., Scheucher et al 2020b;Wunderlich et al 2020) and the ion chemistry model ExoTIC (based on UBIC; see, e.g., Sinnhuber et al 2012).…”

Section: The Modified Increase Model Suitementioning

confidence: 99%

Impact of Cosmic Rays on Atmospheric Ion Chemistry and Spectral Transmission Features of TRAPPIST-1e

Herbst,

Bartenschlager,

Grenfell

et al. 2024

ApJ

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Ongoing observing projects like the James Webb Space Telescope and future missions offer the chance to characterize Earth-like exoplanetary atmospheres. Thereby, M dwarfs are preferred targets for transit observations, for example, due to their favorable planet–star contrast ratio. However, the radiation and particle environment of these cool stars could be far more extreme than what we know from the Sun. Thus, knowing the stellar radiation and particle environment and its possible influence on detectable biosignatures—in particular, signs of life like ozone and methane—is crucial to understanding upcoming transit spectra. In this study, with the help of our unique model suite INCREASE, we investigate the impact of a strong stellar energetic particle event on the atmospheric ionization, neutral and ion chemistry, and atmospheric biosignatures of TRAPPIST-1e. Therefore, transit spectra for six scenarios are simulated. We find that a Carrington-like event drastically increases atmospheric ionization and induces substantial changes in ion chemistry and spectral transmission features: all scenarios show high event-induced amounts of nitrogen dioxide (i.e., at 6.2 μm), a reduction of the atmospheric transit depth in all water bands (i.e., at 5.5–7.0 μm), a decrease of the methane bands (i.e., at 3.0–3.5 μm), and depletion of ozone (i.e., at ∼9.6 μm). Therefore, it is essential to include high-energy particle effects to correctly assign biosignature signals from, e.g., ozone and methane. We further show that the nitric acid feature at 11.0–12.0 μm, discussed as a proxy for stellar particle contamination, is absent in wet-dead atmospheres.

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“…The Exoplanetary Terrestrial Ion Chemistry model ExoTIC is a 1-dimensional stacked-box model of the atmospheric neutral and ion composition (Herbst et al, 2022). The ion-chemistry is based on the UBIC (University of Bremen ion-chemistry) model developed by Winkler et al (2009) for the terrestrial middle atmosphere.…”

Section: Description Of the 1d Model And Experimentsmentioning

confidence: 99%

“…All of the processes like dissociation and dissociative ionisation of O 2 and N 2 as well as ionisation of O 2 , N 2 and O can form the excited states of N, O, N + 2 , N + , NO + which are also included in the model. More details with a full list of the reactions, reactions rates and references for the reactions rates used for the positive ion-chemistry can be found in Sinnhuber et al (2012) and the newer versions in Herbst et al (2022).…”

Section: Full-ion Chemistrymentioning

confidence: 99%

Impact of chlorine ion chemistry on ozone loss in the middle atmosphere during very large solar proton events

Borthakur

Sinnhuber

Laeng

et al. 2023

Preprint

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Abstract. Solar coronal mass ejections can accelerate charged particles, mostly protons, to high energies, causing Solar Particle Events (SPEs). Such energetic particles can precipitate upon the Earth’s atmosphere, mostly in polar regions because of the geomagnetic shielding. Here, SPE induced chlorine activation due to ion-chemistry can occur and the activated chlorine depletes ozone in the polar middle atmosphere. We use a state of the art 1D stacked-box model called Exoplanetary Terrestrial Ion Chemistry (ExoTIC), of atmospheric ion and neutral composition to investigate such events in the Northern Hemisphere (NH). Measurement data from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on Environmental Satellite (ENVISAT) were used to evaluate the model results using the Halloween SPE in late October 2003, a well-known large event, as a test field. Sensitivity tests were carried out for different model settings with a focus on the chlorine species of Hypochlorous acid (HOCl) and Chlorine Nitrate (ClONO2) as well as ozone and odd oxides of nitrogen (NOy). The model studies were carried out in the northern hemisphere for a high latitude of 67.5° N, inside the polar cap. Comparison of the simulated effects against MIPAS observations for the Halloween SPE revealed a rather good temporal and spatial agreement for HOCl, ozone and NOy. For ClONO2, a good spatial agreement was found. The best model setting was the one with full ion-chemistry where oxygen atom in the excited state, O(1D) was set to photo-chemical equilibrium. HOCl and ozone changes are very well reproduced by the model, specially for night-time. HOCl was found to be the main active chlorine species under night-time conditions resulting in an increase of more than 0.2 ppbv. Further, ClONO2 enhancements of 0.2–0.3 ppbv have been observed both during daytime and night-time. In a nutshell, the most appropriate model setting delivers satisfying result, i.e. the model can be considered to be positively validated. Model settings that compared best with MIPAS observations were applied to an extreme solar event in 775 A.D., presumably a once in a 1000 year event. With the model applied to this scenario, assessment can be made what is to be expected at worst for effects of a SPE on the middle atmosphere. Here, a systematic analysis comparing the impact of the Halloween SPE and the extreme event on the Earth’s middle atmosphere is presented. As seen from the model simulations, both events were able to perturb the polar stratosphere and mesosphere, with a high production of NOy and odd oxides of hydrogen (HOx). Longer lasting and stronger stratospheric ozone loss was also seen for the extreme event. Qualitative difference between the two events and a long lasting impact on HOCl and hydrochrolic acid (HCl) for the extreme event was found. Chlorine ion-chemistry contributed to a stratospheric ozone loss of 2.4 % during daytime and 10 % during night-time during the Halloween SPE as seen with time dependent ionisation rates applied to the model. Furthermore, while comparing the two events just for the event day, an ozone loss of 10 % and 20 % was found during the Halloween SPE and the extreme event respectively which was due to the impact of chlorine ion-chemistry.

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INCREASE: An updated model suite to study the INfluence of Cosmic Rays on Exoplanetary AtmoSpherEs

Cited by 4 publications

References 70 publications

Revisiting the cosmic-ray induced Venusian radiation dose in the context of habitability

Revisiting the cosmic-ray induced Venusian radiation dose in the context of habitability

Impact of Cosmic Rays on Atmospheric Ion Chemistry and Spectral Transmission Features of TRAPPIST-1e

Impact of chlorine ion chemistry on ozone loss in the middle atmosphere during very large solar proton events

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