PS9.1

Atmospheres and exospheres of terrestrial planets, satellites, and exoplanets

PS9.1

Atmospheres and exospheres of terrestrial planets, satellites, and exoplanets

Convener: Arianna Piccialli | Co-conveners: Arnaud Beth, Audrey VorburgerECSECS

Presentations

| Wed, 25 May, 17:00–18:25 (CEST)

Room 1.14, Thu, 26 May, 08:30–09:57 (CEST)

Room 1.14

Presentations: Wed, 25 May | Room 1.14

Chairpersons: Arianna Piccialli, Arnaud Beth, Audrey Vorburger

17:00–17:03

Introduction

First sollicited talk (Venus and Mars)

17:03–17:13

EGU22-5687

solicited

Virtual presentation

Studying the middle/upper atmosphere of Venus and Mars combining 3D modeling and observations

Gabriella Gilli, Sebastien Lebonnois, Thomas Navarro, Diogo Quirino, Antoine Martinez, François Forget, Jiandong Liu, Aymeric Spiga, Francisco Gonzalez-Galindo, Ehouarn Millour, and Franck Lefèvre

Our understanding of Venus and Mars climate has been noticeably improved thanks to progress with General Circulation Models (GCM) (e.g., Forget et al. 1999, Lebonnois et al. 2010, Gilli et al. 2021) and increasing measurements, both from space missions and ground-based telescopes. While there are 13 operational missions currently dedicated to Mars, a new era in the exploration of “our sister” planet Venus is coming in the next decades with the selection of 3 missions: DAVINCI and VERITAS by NASA, EnVision by ESA, in addition to the Indian orbiter mission, Shukrayyan-1 (planned for 2025).

Nevertheless, our view of the upper layers of those planets (i.e., above approximately 80 km and 60 km on Venus and Mars, respectively) remains incomplete. The observed high variability of those regions (e.g., Gerard et al. 2014, Gonzalez-Galindo et al. 2015) is very challenging to predict by 3D models. Planetary waves (e.g., Kelvin waves) are suggested to play an important role in the variability in the so-called transition region on Venus (between super-rotation and day-to-night circulation) (Navarro et al. 2021) and gravity waves are recognized to produce a significant impact on the thermal tides of Mars (Gilli et al. 2020).

In this talk, I will give a brief overview of recent 3D GCM developments done in collaboration with the Institut Pierre-Simon Laplace (IPSL) laboratories in France and the Instituto de Astrofisica de Andalucia (IAA) in Spain, such as the inclusion of a stochastic non-orographic gravity wave parameterization and improvements on the parameterization of non-LTE CO₂ heating rates (Martinez et al. 2022, submitted), to provide a more realistic picture of those upper regions of the Venus and Mars atmosphere.

References:

Forget et al. 1999, JGR, 104, 155-24

Lebonnois et al. 2010, JGR-Planets, 115, 6006

Gilli et al. 2021, Icarus, Vol. 366, 114432

Navarro et al. 2021, Icarus, Vol. 366, 114400

Gilli et al. 2020, JGR-Planets, 125-3

Gilli et al. 2017, Icarus, Vol.248, 478-498

Gerard et al. 2014, Icarus, 236, 92-103

Gonzalez-Galindo et al. 2015. JGR-Planets, 120, 2020-2035

Martinez et al. 2022, submitted to Icarus

Acknowledgments:

GG is funded by the Spanish Ministerio de Ciencia, Innovación y Universidades, the Agencia Estatal de Investigación and EC-FEDER funds under project RTI2018-100920-J-I00, and acknowledges financial support from the State Agency for Research of the Spanish MCIU through the “Center of Excellence Severo Ochoa” award to the Instituto de Astrofísica de Andalucía (SEV-2017-0709). This research was also supported by Fundação para a Ciência e a Tecnologia (FCT) through the research grants UIDB/04434/2020, UIDP/04434/2020, P-TUGA PTDC/FIS-AST/29942/2017.

How to cite: Gilli, G., Lebonnois, S., Navarro, T., Quirino, D., Martinez, A., Forget, F., Liu, J., Spiga, A., Gonzalez-Galindo, F., Millour, E., and Lefèvre, F.: Studying the middle/upper atmosphere of Venus and Mars combining 3D modeling and observations, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5687, https://doi.org/10.5194/egusphere-egu22-5687, 2022.

Venus

17:13–17:19

EGU22-2004

Virtual presentation

SO2, SO3, OCS, H2S, and other trace gases in the Venus mesosphere from SOIR on board Venus Express: Detection and upper limit profiles

Arnaud Mahieux, Séverine Robert, Frank Mills, Loïc Trompet, Shohei Aoki, Arianna Piccialli, Kandis Lea Jessup, and Ann Carine Vandaele

We report the detection of SO₂, SO₃, H₂S, and OCS above the cloud deck using the SOIR instrument on-board Venus Express, and upper limit profiles of HOCl, CS, and CS₂.

The SOIR instrument performs solar occultation measurements in the IR region (2.2 - 4.3 µm) at a resolution of 0.12 cm^-1, the highest of all instruments on board Venus Express. It combines an echelle spectrometer and an AOTF (Acousto-Optical Tunable Filter) for the order selection. SOIR performed more than 1500 solar occultation measurements leading to about two millions spectra.

The wavelength range probed by SOIR allows a detailed chemical inventory of the Venus atmosphere at the terminator in the mesosphere, with an emphasis on vertical distribution of the gases.

In this work, we report detections in the mesosphere, between 60 and 100 km.

Implications for the mesospheric chemistry will also be addressed.

How to cite: Mahieux, A., Robert, S., Mills, F., Trompet, L., Aoki, S., Piccialli, A., Jessup, K. L., and Vandaele, A. C.: SO2, SO3, OCS, H2S, and other trace gases in the Venus mesosphere from SOIR on board Venus Express: Detection and upper limit profiles, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-2004, https://doi.org/10.5194/egusphere-egu22-2004, 2022.

17:19–17:25

EGU22-5218

On-site presentation

Wave activity in and below Venusian clouds with the IPSL Venus GCM

Sebastien Lebonnois, Antoine Martinez, and Ehouarn Millour

Recent analyses mostly based on Akatsuki datasets brought many observational informations about the planetary-scale waves (Imai et al., 2019; Kajiwara et al., 2021) and thermal tides (Scarica et al., 2019, Akiba et al., 2021) at the top of the Venusian cloud layer. Further analysis of these data has enabled to build a view of the angular momentum balance at the cloud top, as a component of our understanding of superrotation (Horinouchi et al., 2020).

To help interpret and understand these wave activities and their impact on the angular momentum budget both in and below the cloud layer, the Venus Global Climate Model (GCM) we are developing at Institut Pierre-Simon Laplace (IPSL) is used in its latest configuration. Similarly to what was done with earlier configurations (Lebonnois et al., 2016), waves are extracted from the simulations to analyze (i) the thermal tide components, (ii) the dominant planetary-scale waves present in the cloud layer, Kelvin- and Rossby-type waves with periods close to 4-6 Earth days, and (iii) wave activity occurring in the deep atmosphere, below the cloud, corresponding to large-scale inertio-gravity waves. These different waves will be compared to observations to assess how the IPSL Venus GCM reproduces observational constraints. Angular momentum budget as evaluated in the GCM simulations will be discussed, with emphasis on the cloud top region.

References:

Akiba M. et al. (2021), JGR Planets 126, doi:10.1029/2020JE006808

Horinouchi T. et al. (2020), Science 368, 405–409, doi:10.1126/science.aaz4439

Imai M. et al. (2019), JGR Planets 124, doi:10.1029/2019JE006065

Kajiwara N. et al. (2021), JGR Planets 126, doi:10.1029/2021JE007047

Lebonnois S et al. (2016), Icarus 278, 38-51, doi:10.1016/j.icarus.2016.06.004

Scarica P. et al. (2019), Atmosphere 10, 584, doi:10.3390/atmos10100584

How to cite: Lebonnois, S., Martinez, A., and Millour, E.: Wave activity in and below Venusian clouds with the IPSL Venus GCM, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5218, https://doi.org/10.5194/egusphere-egu22-5218, 2022.

17:25–17:31

EGU22-10705

ECS

Virtual presentation

Venus Dynamics on the framework of Bepicolombo flyby to Venus and Akatsuki UVI coordinated observations with TNG HARPS-N observations

Daniela Espadinha, Pedro Machado, Javier Peralta, José Silva, and Francisco Brasil

With this work we present new results of studies of zonal and meridional winds in both Venus’ hemispheres, using ground- and space-based coordinated observations. The wind velocities retrieved from space used an improved cloud-tracked technique and the results obtained from telescope observations were retrieved with a Doppler velocimetry method, both described below. There is evidence that the altitude level sensed by the Doppler velocimetry method is approximately four kilometres higher than that using ground-tracked winds which is shown by models which predict wind profiles developed at the Laboratoire de Meteorologie Dynamique (Machado et al., Atmosphere,2021).

Initially developed by Thomas Widemann (Widemann et al., Planetary and Space Science 56, 2008), the Doppler velocimetry method was further evolved by Pedro Machado for both long slit and fibre-fed spectrographs, using UVES/VLT and ESPaDOnS/CFHT respectively. This technique is based on solar light scattered on Venus’ dayside and provides instantaneous wind velocities measurements of its atmosphere. (Machado et al., Icarus, 2012; Icarus 2014; Icarus 2017).

The cloud-tracking method consists of an analysis of a pair of navigated and processed images, provided that the time interval between both is known. It is possible to probe the motion of cloud features between the initial and second image, either by matching specific areas or points in both images. This matching process allows us to measure velocities of cloud features and deduct the average velocity for a certain cloud layer of the atmosphere, selected in the wavelength range of the observations (Peralta et al., The Astrophysical Journal Supplement Series 239, 2018).

An evolved tool of cloud tracking based on phase correlation between images and other softwares (Hueso et al., Advances in Space Research, 2010) allowed to explore Venus' atmospheric dynamics based on coordinated space and ground observations including Akatsuki UVI instrument, TNG/HARPS-N, and data from BepiColombo’s first Venus' flyby.

The main goal of this work was to build wind profiles in different wavelengths, allowing us to analyse several layers of the Venusian atmosphere. We present some results of this study following the works of Sánchez-Lavega et al., Geophysical Research Letters 35, 2008; Hueso et al. 2013 and Horinouchi et al., Planets and Space, 2018 and compare them with ground-based Doppler measurements (Machado et al., Atmosphere,2021).

Acknowledgements
We thank the JAXA’s Akatsuki team for support with coordinated observations. We gratefully acknowledge the collaboration of the TNG staff at La Palma (Canary Islands, Spain) - the observations were made with the Italian Telescopio Nazionale Galileo operated on the island of La Palma by the Fundación Galileo Galilei of the Istituto Nazionale di Astrofisica at the Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. We acknowledge support from the Portuguese Fundação Para a Ciência e a Tecnologia project PTUGA (ref. PTDC/FIS-AST/29942/2017) through national funds and by FEDER through COMPETE 2020 (ref. POCI-01-0145 FEDER-007672) and through a grant of reference 2020.06389.BD.

How to cite: Espadinha, D., Machado, P., Peralta, J., Silva, J., and Brasil, F.: Venus Dynamics on the framework of Bepicolombo flyby to Venus and Akatsuki UVI coordinated observations with TNG HARPS-N observations, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10705, https://doi.org/10.5194/egusphere-egu22-10705, 2022.

Mars

17:31–17:37

EGU22-4598

On-site presentation

Detection and comparison of Martian seasonal frost boundaries in OMEGA observations and LMD GCM simulations around the North Pole

André Szantai, François Forget, Thomas Appéré, and Bernard Schmitt

This study focuses on the water cycle around the Northern seasonal polar cap from the end of autumn to the following spring season, and more precisely on the progression and retreat of CO₂ and H2O frosts observed by the Martian Global Climate Model (GCM) of the LMD and by the OMEGA imaging spectrometer onboard Mars Express.

Based on a series of OMEGA observations from the end of autumn of MY 27 (Ls ~260°) to the end of spring of MY 28, Appéré et al. (2011) described the temporal evolution of H₂O and CO₂ ice deposits, constantly evolving northwards through sublimation and deposition of the corresponding ice/frost. This ends just before the summer solstice (around Ls ~70°) after the complete disappearance of CO₂ ice. At high latitudes, the sublimation of frost then contributes to an abundant emission of water vapor.

The LMD Martian GCM is able to reproduce the global and seasonal water and CO₂ cycles during the winter-spring seasons. However, it releases excessive humidity in the polar region. In order to improve the model, we examine and compare the southernmost position of frosts and their poleward progression on Martian GCM data and on spectral images from OMEGA.

In OMEGA data, water and CO₂ frosts can be detected by absorption bands at 1.5 μm, respectively at 1.43 μm (Langevin et al., 2007). Similarly, when the depth of the absorption band falls below a chosen value, the frost is considered as having disappeared. On one orbit-segment image, the southernmost pixels form a more or less continuous line corresponding to the frost boundary (“crocus-line” type).

In the model simulation, we use the surface ice contents provided by the LMD GCM (Forget et al., 1999) in order to detect the frost dissipation. Water (resp. CO₂) ice content values (in kg/m²) have been calculated on a regular grid (5.625° longitude x 3.75° latitude) 4 times per sol (at 0, 6, 12 and 18 h LT) over one Martian year. Starting at the end of the northern autumn (Ls ~ 260°), the evolution of the water (CO2) ice content can be examined at every grid point.

In most cases, all the OMEGA pixels of an image are observed at the same local time. We calculate an average GCM frost dissipation time Ls_{fd_GCM} from the 4 closest GCM neighbor grid points, weighted by the distance between each GCM grid point and the OMEGA frost line. Then the time interval between the dissipation of frost in OMEGA water (CO₂) ice absorption depth profile and in the collocated (interpolated) water ice disappearance on the GCM can be determined.

With a perfect GCM and well-chosen frost-detection thresholds on both datasets, the dissipation of frost should be simultaneous for collocated data in both datasets. Otherwise, when the frost time dissipation interval DLs_fd = Ls_{fd_OMEGA} - Ls_{fd_GCM} is positive (respectively negative), the model is late (in advance) w.r.t. observations. We will present results of the evolution of the frost time dissipation during the winter-spring season.

How to cite: Szantai, A., Forget, F., Appéré, T., and Schmitt, B.: Detection and comparison of Martian seasonal frost boundaries in OMEGA observations and LMD GCM simulations around the North Pole, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4598, https://doi.org/10.5194/egusphere-egu22-4598, 2022.

17:37–17:43

EGU22-11552

ECS

Virtual presentation

Analysis of transport and mixing of generic trace gases in the martian atmosphere with MRAMS

Jorge Pla-Garcia, Scot C.R. Rafkin, and María Ruíz-Pérez

The Mars Regional Atmospheric Modeling System (hereafter MRAMS, Rafkin & Michaels, [2019]) is used to simulate, via passive (inert) tracers, the 3-D atmospheric transport, dispersion and mixing of trace gases released at different locations from instantaneous releases, and to evaluate whether air masses could make it to specific locations. The objective is to study if circulation (mean or regional) is favorable for transport trace gases from any point of the planet to specific locations. With the corresponding caveats, our modeling results can be used to investigate transport and mixing of trace gases like water vapor or methane. In these MRAMS experiments, a total of 18 tracers are strategically placed quasi-globally in the computational mother domain. Tracers are placed in 30 degree latitude belts (-90->-60, -60->-30, -30->0, 0->30, 30->60, 60->90) and then at above ground levels from 0-10 km, 10-30 km, and 30 km-model top. We can determine from which latitude belt air is coming/going and from what level in the atmosphere. The tracers also provide the means to quantify atmospheric mixing, diagnosed by evaluating the fraction of a given tracer mixing ratio compared to the total as a function of time. Tracer experiments show that northern high latitude air masses can be transported with very little dilution to some lower latitude locations, including Hrad Vallis and Jezero Crater. In other locations, source air masses are highly diluted.

How to cite: Pla-Garcia, J., Rafkin, S. C. R., and Ruíz-Pérez, M.: Analysis of transport and mixing of generic trace gases in the martian atmosphere with MRAMS, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11552, https://doi.org/10.5194/egusphere-egu22-11552, 2022.

17:43–17:49

EGU22-8087

ECS

Virtual presentation

Characterising Atmospheric Gravity Waves on Mars - a systematic study

Francisco Brasil, Pedro Machado, Gabriella Gilli, Alejandro Cardesín-Moinelo, José Eduardo Silva, Daniela Espadinha, Rafael Rianço-Silva, Francisco Rodrigues, and Brigitte Gondet

Atmospheric gravity waves are mesoscale atmospheric oscillations in which buoyance acts as the restoring force, being a crucial factor in the circulation of planetary atmospheres since they transport momentum and energy, which can dissipate at different altitudes and force the dynamics of several layers of the atmosphere [1]. The source of these waves can be associated with the topographic features (orographic gravity waves) of surface, or with jet streams and atmospheric convections (non-orographic gravity waves). Recent modelling studies showed the strong role of gravity waves on diurnal tides on Mars atmosphere [2], however their characteristics are still not well constrained by observations.

We present here follow-up results [3] on the detection and characterization of atmospheric gravity waves on Mars using data from the OMEGA (Observatoire pour la Minéralogie, l'Eau, les Glaces et l'Activité) [4] imaging spectrometer onboard the European Mars Express (MEx) space mission [5]. We used image navigation and processing techniques based on contrast enhancement and geometrical projections to characterize morphological properties of the detected waves.

Our observations include 11 months’ worth of data from the first nominal mission of Mars Express, from January 2004 to November 2004. Every image was navigated and processed in order to optimise the detection of the wave packets and accurate characterisation of the wave properties such as the horizontal wavelength, packet width, packet length and orientation. We characterised almost 100 wave-packets across more than 1300 images over a broad region of Mars’ globe and our results show a wide range of properties specially in the evolution of gravity waves along the time, due to the time sampling and global coverage of MEx.

Acknowledgments: This work is supported by Fundação para a Ciência e a Tecnologia (FCT)/MCTES through the research grants UIDB/04434/2020, UIDP/04434/2020, and through a grant of reference 2021.05455.BD.

References

[1] Fritts, D. C.; Alexander, M. J. Gravity wave dynamics and effects in the middle atmosphere. Reviews of geophysics, 2003, 41.1.

[2] Gilli, G., et al. Impact of gravity waves on the middle atmosphere of Mars: A non‐orographic gravity wave parameterization based on global climate modeling and MCS observations. Journal of Geophysical Research: Planets, 2020, 125.3: e2018JE005873.

[3] Brasil, Francisco, et al. Characterising Atmospheric Gravity Waves on Mars using Mars Express OMEGA images–a preliminary study. In: European Planetary Science Congress. 2021. p. EPSC2021-188.

[4] Bibring, J. P., et al. OMEGA: Observatoire pour la Minéralogie, l'Eau, les Glaces et l'Activité. In: Mars Express: the scientific payload. 2004. p. 37-49.

[5] Chicarro, A.; Martin, P.; Trautner, R. The Mars Express mission: an overview. In: Mars Express: The Scientific Payload. 2004. p. 3-13.

How to cite: Brasil, F., Machado, P., Gilli, G., Cardesín-Moinelo, A., Eduardo Silva, J., Espadinha, D., Rianço-Silva, R., Rodrigues, F., and Gondet, B.: Characterising Atmospheric Gravity Waves on Mars - a systematic study, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8087, https://doi.org/10.5194/egusphere-egu22-8087, 2022.

17:49–17:55

EGU22-10557

ECS

On-site presentation

Probing Martian turbulence kinetic energy and dissipation rate during major dust storms

Cem Berk Senel, Orkun Temel, and Ozgur Karatekin

Turbulence in lower layers of terrestrial atmospheres, i.e., the planetary boundary layers (PBL), is the key governor of near–surface exchange of momentum, aerosols and tracers [1]. As the in–situ exploration of Mars by lander and rover missions advances progressively, the dynamics of atmospheric turbulence has drawn growing attention to better understand the Martian near–surface processes.

Recent in–situ observations [2, 3] introduced new features of near–surface Martian turbulence, such as, the day and nighttime vortex activity, local and non–local turbulence. Very recently, we presented the feedback between convective turbulence activity and major dust storms derived from general circulation model (GCM) simulations with an in-house semi–interactive dust transport model [4], guided by column dust climatology observations [5]. In the present study, we further examine the near–surface turbulence activity addressing the turbulence kinetic energy, k, and dissipation rate, ε, of lower atmosphere. These quantities, as the two key physical quantity in classical turbulence theory, provide valuable insights into Martian turbulence characteristics, indicating the integral energy content of atmospheric turbulence and irreversible energy conversion into heat, respectively. Here, we mainly focus on two questions: how does the near-surface k–ε (i) change seasonally and (ii) relate to the major dust storm activity in Martian Years 34 and 35. To this end, we perform high–resolution MarsWRF [6, 7] mesoscale simulations in Elysium Planitia using our recent Mars–specific PBL scheme [8], assessed with the global variation of Martian PBL [4]. As a future study, we will support our findings with the high temporal–resolution surface meteorological observations.

[1] Petrosyan, A., Galperin, B., ... & Vázquez, L. (2011). The Martian atmospheric boundary layer. Reviews of Geophysics, 49(3).
[2] Banfield, D., Spiga, A., ... & Banerdt, W. B. (2020). The atmosphere of Mars as observed by InSight. Nature Geoscience, 13(3), 190–198.
[3] Chatain, A., Spiga, A., Banfield, D., Forget, F., & Murdoch, N. (2021). Seasonal Variability of the Daytime and Nighttime Atmospheric Turbulence Experienced by InSight on Mars. Geophysical Research Letters, 48(22), e2021GL095453.
[4] Senel, C. B., Temel, O., Lee, C., Newman, C. E., ... & Karatekin, Ö. (2021). Interannual, Seasonal and Regional Variations in the Martian Convective Boundary Layer Derived From GCM Simulations With a Semi–Interactive Dust Transport Model. JGR: Planets, 126(10), e2021JE006965.
[5] Montabone, L., Spiga, A., ... & Millour, E. (2020). Martian year 34 column dust climatology from Mars climate sounder observations: Reconstructed maps and model simulations. JGR: Planets, 125(8), e2019JE006111.
[6] Richardson, M. I., Toigo, A. D., & Newman, C. E. (2007). PlanetWRF: A general purpose, local to global numerical model for planetary atmospheric and climate dynamics. JGR: Planets, 112(E9).
[7] Newman, C. E., Kahanpää, H., Richardson, M. I., ... & Lemmon, M. T. (2019). MarsWRF convective vortex and dust devil predictions for Gale Crater over 3 Mars years and comparison with MSL–REMS observations. JGR: Planets, 124(12), 3442–3468.
[8] Temel, O., Senel, C. B., Porchetta, S., Muñoz–Esparza, D., ... & Karatekin, Ö. (2021). Large eddy simulations of the Martian convective boundary layer: towards developing a new planetary boundary layer scheme. Atmospheric Research, 250, 105381.

How to cite: Senel, C. B., Temel, O., and Karatekin, O.: Probing Martian turbulence kinetic energy and dissipation rate during major dust storms, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10557, https://doi.org/10.5194/egusphere-egu22-10557, 2022.

17:55–18:01

EGU22-8298

ECS

On-site presentation

Mesoscale modeling of the Arsia Mons Elongated Cloud (AMEC) on Mars

Jorge Hernandez Bernal, Aymeric Spiga, Agustín Sánchez-Lavega, Teresa Del Río-Gaztelurrutia, François Forget, and Ehouarn Millour

A recent work (Hernández-Bernal et al., 2021) described the Arsia Mons Elongated Cloud (AMEC), an impressive orographically generated cloud that appears next to the Arsia Mons volcano on Mars during the early morning on a daily basis in southern spring and summer. The most visually striking characteristic of this cloud is its extremely elongated shape.

This spectacular cloud is formed by underlying dynamical and microphysical processes that remain to be elucidated. To that end, we run the LMD (Laboratoire de Météorologie Dynamique) MMM (Mars Mesoscale Model; Spiga and Forget, 2009) for Solar Longitude 270º, with a grid resolution of 10km. The model shows that the interaction of fast transient easterly winds with the summit of Arsia Mons results in strong ascending winds on the western slope of the volcano, seasonally and diurnally coincident with the occurrence of the AMEC according to observations. These ascending winds propagate vertically and result in a temperature drop which takes values of down to -30K in the hygropause (around 45 km over the areoid). This results in extreme relative humidity values and condensation, spatially coincident with what Hernández-Bernal et al. (2021) called the head of the AMEC. We expect advection by easterly winds to produce the particular elongated shape of the AMEC, however the advection of condensed particles is not clearly reproduced by the model.

This AMEC study demonstrates that coupling the analysis of mesoscale modeling with imagery monitoring on elongated clouds help to better understand the involved processes to form the cloud. We aim to search for similar mechanisms in other visually resemblant clouds, like those reported by Clancy et al. (2006; 2021), and others observed by the Visual Monitoring Camera onboard Mars Express, among other imagers. In the meantime, the AMEC is expected to appear again in early June 2022 and different instruments are already planning observations.

References:

Hernández‐Bernal, Jorge, et al. "An extremely elongated cloud over Arsia Mons volcano on Mars: I. Life cycle." Journal of Geophysical Research: Planets 126.3 (2021): e2020JE006517.
Spiga, Aymeric, and François Forget. "A new model to simulate the Martian mesoscale and microscale atmospheric circulation: Validation and first results." Journal of Geophysical Research: Planets 114.E2 (2009).
Clancy, R. Todd, et al. "Valles Marineris cloud trails." Journal of Geophysical Research: Planets 114.E11 (2009).
Clancy, R. Todd, et al. "Mars perihelion cloud trails as revealed by MARCI: Mesoscale topographically focused updrafts and gravity wave forcing of high altitude clouds." Icarus 362 (2021): 114411.

How to cite: Hernandez Bernal, J., Spiga, A., Sánchez-Lavega, A., Del Río-Gaztelurrutia, T., Forget, F., and Millour, E.: Mesoscale modeling of the Arsia Mons Elongated Cloud (AMEC) on Mars, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8298, https://doi.org/10.5194/egusphere-egu22-8298, 2022.

Discussion

18:01–18:07

EGU22-10301

Virtual presentation

Mars Atmosphere Simulations With ROCKE-3D: Nonlinear Dust Cycle Behavior Linked to Dust Radiative Effect

Jan P Perlwitz, Kostas Tsigaridis, Igor Aleinov, Scott D Guzewich, Michael J Way, and Eric T Wolf

We present simulation results of the dust cycle on Mars using the NASA Goddard Institute for Space Studies (GISS) ROCKE-3D [1] general circulation model with radiatively active dust aerosol tracers. Dust aerosols are represented by a sectional scheme that partitions the simulated dust mass into eight size classes, covering a total size range from 0.1 to 32 μm particle diameter. The model simulates emission from sources, advection, and turbulent, gravitational, and wet deposition of dust. The strength of the dust cycle can be calibrated with a global factor for the dust emission. ROCKE-3D is coupled to the Suite of Community Radiative Transfer codes based on Edwards and Slingo (SOCRATES) [2,3], which applies Mie theory to calculate scattering and absorption of radiation by aerosols. We carried out a series of experiments over 11 Mars years, for which we varied the strength of the dust cycle, and for radiatively active and inactive dust. The simulated dust aerosol optical depths were compared to gridded retrievals of the dust AOD from measurements over 11 years [4, 5]. We find that the dust cycle displays nonlinear behavior with the strength of emission, when the dust is radiatively active, which is absent for radiatively inactive dust. When the dust cycle strength exceeds a certain threshold the simulated mean annual cycle of dust starts to exhibit features that are similar to the observed mean annual cycle. We hypothesize that feedbacks involving the dust radiative effect introduce important non-linearities, which are essential for reproducing and understanding the observed dust cycle on Mars.

References: [1] Way, M. J. et al. (2017) ApJS, 231, 12.
[2] Edwards, J. M. (1996), JAtS, 53, 1921.
[3] Edwards, J. M., & Slingo, A. (1996), QJRMS, 122, 689.
[4] Montabone, L. et al. (2015) Icarus, 251, 65.
[5] Montabone, L. et al. (2020) JGR Planets, 2019JE006111.

How to cite: Perlwitz, J. P., Tsigaridis, K., Aleinov, I., Guzewich, S. D., Way, M. J., and Wolf, E. T.: Mars Atmosphere Simulations With ROCKE-3D: Nonlinear Dust Cycle Behavior Linked to Dust Radiative Effect, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10301, https://doi.org/10.5194/egusphere-egu22-10301, 2022.

18:07–18:13

EGU22-1367

ECS

On-site presentation

Ionospheric plasma depletions at Mars as observed by MAVEN

Praveen Kumar Basuvaraj, Frantisek Nemec, Zdenek Nemecek, and Jana Safrankova

The Martian ionosphere, modulated by the solar wind from the topside and by remnant crustal magnetic fields close to the surface, possess unique structures different from Earth and Venus. Integrated observations by the plasma and magnetic field instruments onboard the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft show clear evidence of ionospheric plasma depletions, independent of seasonal variations at Mars. During such depletions, the plasma density of all ionospheric ion species is reduced by up to an order of magnitude and, at the same time, the electron temperature increases abruptly. An automated algorithm for the identification of such plasma depletions is developed. Altogether, as many as 580 events are identified in 8619 orbits available from October 2014 to May 2021. A statistical investigation of these events reveals that they are more prominent on the night side and occur at altitudes between 150 and 500 km. Considering the spacecraft velocity and the observed event durations, we suggest that the depletions are bubble-like structures, more elongated horizontally than vertically. A possible mechanism of their formation is discussed.

How to cite: Basuvaraj, P. K., Nemec, F., Nemecek, Z., and Safrankova, J.: Ionospheric plasma depletions at Mars as observed by MAVEN, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-1367, https://doi.org/10.5194/egusphere-egu22-1367, 2022.

Discussion

18:13–18:19

EGU22-10708

ECS

Presentation form not yet defined

A Global Perspective on Martian Meteoric Mg+

Matteo Crismani, Robert Tyo, Nicholas Schneider, John Plane, Wuhu Feng, Geronimo Villanueva, Sonal Jain, and Justin Deighan

Interplanetary dust particles, liberated from the surfaces of comets and asteroids, are ubiquitous in interplanetary space within the solar system. These particles travel at orbital velocities and ablate upon entry into planetary atmospheres, where they are the sole explanation for high altitude atmospheric metal layers. On Earth, such layers inform us of the dynamics of the upper atmosphere, and we use the abundance of relative species to investigate the origin of these particles from various potential sources (Jupiter family comets, asteroids, etc.). Since the discovery of atmospheric Mg+ at Mars in 2015, there have been almost continuous observations of this layer in a variety of seasons, local times, and latitudes. Here we present the most comprehensive set of observations of the persistent metal ion layer at Mars, constructing the first grand average maps of metal ions species. Such maps can be compared to current and future modeling efforts, which attempt to track mesospheric transport, chemistry and interplanetary dust particle sources. This work confirms some previous model predictions and observations, such as the relatively long lifetime of Mg+, but also presents counter-intuitive results, such as a paucity of Mg+ ions in the northern hemisphere during Northern Winter in an apparent correlation with dust aerosols. Previous discrepancies between model predictions and metal ion observations led to the development of a novel nucleation scheme for mesospheric clouds, and we revisit these ideas on a global and seasonally varying scale. Overall, this represents the broadest investigation of meteoric metal ions, summarizes the first order behavior and outlines new model challenges for the future.

How to cite: Crismani, M., Tyo, R., Schneider, N., Plane, J., Feng, W., Villanueva, G., Jain, S., and Deighan, J.: A Global Perspective on Martian Meteoric Mg+, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10708, https://doi.org/10.5194/egusphere-egu22-10708, 2022.

18:19–18:25

EGU22-10155

Presentation form not yet defined

New C-CO2 scattering cross sections at eV energies and their impact on photochemical escape of Carbon from Mars

(withdrawn)

Marko Gacesa

Solar System atmospheres

Presentations: Thu, 26 May | Room 1.14

Chairpersons: Arnaud Beth, Arianna Piccialli, Audrey Vorburger

08:30–08:36

EGU22-7138

Virtual presentation

Impact of broadening line parameters on H2O retrievals in CO2 dense atmospheres

Séverine Robert, Justin T. Erwin, Robert R. Gamache, Bastien Vispoel, Bruno Grouiez, and Laurence Régalia

For decades, the remote sensing measurements have been made in planetary atmospheres in the Solar System and beyond. As the performance of the space instruments improves, the atmospheric science community is more and more in need of accurate spectroscopic data. The current databases offer some parameters for non-Earth atmospheres but are far from complete for all situations. For example, measured H₂O line parameters in CO₂-rich atmospheres such as Mars and Venus are missing while they are of prime importance to learn about the evolution of the atmospheres.

After the study published in 2019 by Régalia et al., we measured new Fourier Transform Spectrometer spectra in the 1.88 micron range using a Connes’ type FT spectrometer built in Reims. The spectra were analysed using a multispectrum fitting procedure to obtain the line-shape parameters of H₂O broadened by CO₂. These results were used to constrain the intermolecular potential and to calculate the half-width, line shift, and their temperature dependence using the Modified Complex Robert-Bonamy formalism.

The impact of these new parameters on the spectral retrievals in the atmospheres of Mars and Venus will be assessed by calculating the equivalent widths in different cases. This exercise may highlight once more that using the correct line shape and line parameters is of utmost importance now that our space instruments have high spectral resolution. More especially the impact of the Double Power law (Gamache and Vispoel, 2018) for the temperature dependence parameter is tested in the context of the scientific preparation of VenSpec-H, spectrometer part of the EnVision payload.

How to cite: Robert, S., Erwin, J. T., Gamache, R. R., Vispoel, B., Grouiez, B., and Régalia, L.: Impact of broadening line parameters on H2O retrievals in CO2 dense atmospheres, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7138, https://doi.org/10.5194/egusphere-egu22-7138, 2022.

08:36–08:42

EGU22-6192

ECS

Virtual presentation

From atmospheric evolution to the search of species of astrobiological interest in the Solar System – Case-Studies using the Planetary Spectrum Generator

João Dias, Pedro Machado, José Ribeiro, and Constança Freire

We used the Planetary Spectrum Generator (PSG) [1] a radiative transfer suite, with the goal of simulating spectra from observations of Venus, Mars and Jupiter, searching for minor chemical species.

For Venus, sulphur dioxide (SO₂) absorption lines were detected and its abundance constrained, by comparing simulations with observations by the Texas Echelon Cross Echelle Spectrograph (TEXES) spectrograph, around 7.4 μm [2]. The mean abundance of SO₂ was constrained to 120 ppb, using the Optimal Estimation Method [3] and a line-depth ratio method [2] independently, in agreement with 50-175 ppb obtained by Encrenaz et al [2]. Phosphine (PH3) was not detected in the comparison between simulation and TEXES Infrared (IR) observations [4], around 10.5 μm, due to the presence of a strong telluric water band in the spectra.

For Mars, both a positive and a negative detection of methane were reanalyzed using PSG simulations with the goal of constraining the methane abundance. The related spectra observations in the IR, around 3.3 μm, report, respectively, to the Mars Express (MEx) [5] and ExoMars [6] space-probes.

For Jupiter, the detection of ammonia, phosphine, deuterated methane and methane was studied, by comparing simulations with IR observations by the Infrared Space Observatory (ISO), around 7-12 μm. [7]. The next step is focused in the determination of the abundances of the previous species. Independent simulations will be performed using PSG and the NEMESIS state-of-the-art radiative transfer suite [8]

Funding: This research was funded by the Portuguese Fundacao Para a Ciencia e Tecnologia under project P-TUGA Ref. PTDC/FIS-AST/29942/2017 through national funds and by FEDER through COMPETE 2020 (Ref. POCI-01-0145 FEDER-007672).

Aknowledgments: We credit Thérèse Encrenaz, from LESIA, Observatoire de Paris, for all the support and fruitful discussion; Geronimo Villanueva, from NASA-Goddard Space Flight Center, for discussing issues regarding PSG; Marco Giuranna, PI of the PFS instrument of Mars Express (ESA), Alejandro Cardesín, from ESAC-ESA, Ann Carine Vandaele, PI of the NOMAD instrument of ExoMars (ESA) and Séverine Robert, from the ExoMars team, for all the support regarding Mars dedicated research; Gabriella Gilli (IAA), for the collaboration regarding the LMD-VGCM model; Patrick Irwin, from the University of Oxford (UK), for the collaboration under the NEMESIS radiative transfer code; Asier Munguira, from the University of the Basque Country, for his availability to discuss atmospheric research methods in the context of the present work.

References

[1] Villanueva et al. 2018, Journal of Quantitative Spectroscopy and Radiative Transfer

[2] Encrenaz et al. 2012; Astronomy & Astrophysics

[3] C. D. Rodgers. Inverse methods for atmospheric sounding: theory and practice. World Scientific, 2008

[4] Encrenaz et al. 2020; Astronomy & Astrophysics.

[5] Giuranna et al. 2019; Nature

[6] Korablev et al. 2019.; Nature

[7] Encrenaz et al. 1999 ; Planetary and Space Science

[8] Irwin et al. 2008 ; Journal Of Quantitative Spectroscopy And Radiative Transfer

How to cite: Dias, J., Machado, P., Ribeiro, J., and Freire, C.: From atmospheric evolution to the search of species of astrobiological interest in the Solar System – Case-Studies using the Planetary Spectrum Generator, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6192, https://doi.org/10.5194/egusphere-egu22-6192, 2022.

08:42–08:47

Discussion break

Titan (Break here or after)

08:47–08:53

EGU22-6641

ECS

Virtual presentation

Mesoscale climate modeling above a methane lake on Titan

Audrey Chatain, Scot C.R. Rafkin, Alejandro Soto, and Ricardo Hueso

Titan is the only known place beyond the Earth to have lakes and seas. On Earth, we know that liquid surfaces are constantly subject to evaporation and that they strongly modify the local climate and drive the planet water cycle. Then, what climate could we expect on Titan in the environment of methane lakes? And how their evaporation does control the methane cycle? We investigate this using mesoscale climate modeling. Currently there are no advanced mesoscale or large eddy simulation models of Titan. The first models came out only very recently, by Rafkin & Soto (2020), Lavely et al (2021) and Spiga et al (2020). Each focuses on a specific point (methane evaporation, topography, turbulence), but none of them handles all of the key processes yet.

We use the mtWRF 2D model first described in Rafkin & Soto (2020), which simulates the effect of a methane lake on the local climate. The model previously lacked the implementation solar insolation and radiative transfer. However, previous results in Rafkin & Soto (2020) suggested that these effects could be important on the lake-induced wind circulation. We thus added a simple gray radiative transfer scheme to the model. It takes into account solar radiation scattering through the atmosphere [Adamson 1975] and reflection at the surface, as well as IR radiation emission and absorption in the atmosphere and at the surface [Schneider et al 2012].

Simulations with and without radiative transfer both show the formation of a sea breeze (with surface winds from the lake to the land), which extends well outside the limits of the lake. The simulation with radiative transfer shows the formation of the strongest winds during daytime and at the lake shores (because of an increase of the temperature difference between the quickly warming land and the slowly warming lake).

Methane evaporation is also the most efficient on the lake shores, where and when winds are the strongest. Methane vapor is then spread over land by the winds.

The diurnally-varying insolation induces an oscillation on the land and lake surface temperatures. The lake is slower to react because of the increase of evaporation during the day, which has a cooling effect opposite to the solar warming. As they undergo stronger evaporation, the side parts of the lake stabilize at a lower temperature than the center. The resulting mean lake surface temperature is increased by a few Kelvins compared to the case without radiative transfer.

Our short term next step is to investigate the effects of seasons on lake evaporation and the local atmospheric circulation. Strong winds are caused by evaporative effects on lakes at Titan’s poles, but this could also happen on wetlands at all latitudes, and in particular at Dragonfly’s landing site [Niemann et al 2010]. To help prepare for mission flight operations, we therefore aim to model evaporation above wetlands in the near future.

This project has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No 101022760.

How to cite: Chatain, A., Rafkin, S. C. R., Soto, A., and Hueso, R.: Mesoscale climate modeling above a methane lake on Titan, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6641, https://doi.org/10.5194/egusphere-egu22-6641, 2022.

08:53–08:59

EGU22-9643

ECS

On-site presentation

Developing an Idealised Climate Model of Titan

Daniel Williams, Geoffrey Vallis, Stephen Thomson, and William Seviour

Our understanding of Saturn’s moon Titan has substantially increased during the past two decades. The successful Cassini-Huygens mission provided a wealth of measurements within the atmosphere itself. Despite our advances in understanding, much about Titan and its atmosphere are still unknown.
Aside from Earth, it is the only planet-like object in our Solar System to possess a hydrological cycle (using methane) and a thick atmosphere, but it also has significant differences from Earth in its dynamics and structure. As such, questions relating to the atmosphere's origin, long-term stability and stratospheric circulation remain unanswered.

The remoteness of Titan makes it difficult to study from Earth in much detail, with the next chance over a decade away in the form of the NASA Dragonfly mission. It does however provide an excellent opportunity to make use of computational methods to better understand the moon's unique atmosphere. We make use of an existing climate modelling framework (Isca) to develop an idealised model for Titan; this captures the key features of its atmosphere and circulation without introducing superfluous complexity. This model incorporates Titan's unique dynamics and moist physics, and hence can be used to test various aspects of the atmosphere in the absence of more complete observational data. We aim to test the stability of the atmosphere with respect to a methane-attributed runaway greenhouse effect using a full radiation code, varying insolation and hydrological budget

How to cite: Williams, D., Vallis, G., Thomson, S., and Seviour, W.: Developing an Idealised Climate Model of Titan, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9643, https://doi.org/10.5194/egusphere-egu22-9643, 2022.

Second sollicited talk (Mercury))

08:59–09:09

EGU22-4364

solicited

On-site presentation

The sodium exosphere of Mercury and its dynamics

Valeria Mangano

The exosphere is the upper layer of a planetary atmosphere, and the last planetary territory before the interplanetary medium. In case of planets without a proper atmosphere, as Mercury, the exosphere is also the only kind of ‘atmosphere’ the planet possesses, and it is directly in contact with the surface. Due to this peculiarity, its origin is mainly from the surface outgassing, through a complex series of processes that acts as sources. The exospheric composition is then strictly related to the planet surface, but also to the other many interactions that the exosphere experiences with: the solar wind radiation and particles, the intrinsic magnetic field and ions circulation, the interplanetary magnetic field, the (micro)meteoritic bombardment. In addition, the interaction with the previously cited elements may also cause depletion. As a consequence, the exosphere of Mercury experiences an intense spatial and temporal variability.

The resulting dynamics of the exosphere of Mercury is evidenced in the studies of the sodium component that is a perfect tracer of the hidden interactions with the surrounding environment.

MESSENGER mission in the last decade highlighted the strong interchange with the intrinsic magnetic field, and the Earth-based observations with the interplanetary magnetic field. In the next future, the BepiColombo mission to Mercury, launched in October 2018, with its instrumentation devoted to the study of the magnetic field, ions and neutral particles will contribute to a comprehensive explanation of the processes and interactions that generate, sustain and change it.

How to cite: Mangano, V.: The sodium exosphere of Mercury and its dynamics, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4364, https://doi.org/10.5194/egusphere-egu22-4364, 2022.

Exospheres of airless bodies

09:09–09:15

EGU22-1986

ECS

Virtual presentation

Hydro cyclone flow as a physical process of ejection of material in the plumes of Enceladus and influence in the atmosphere.

Katherine Villavicencio Valero, Emilio Ramírez-Juidías, and Pascal Allemand

On Enceladus, the first sign of water vapor plumes was detected by the UVIS instrument of Cassini during a stellar occultation in July 2005. The dynamics of these water plumes, probably related to the ocean activity, are an important subject of study in order to understand the exchange of material from this ocean into the atmosphere. There are different theories that might explain the physical processes that allow for the expulsion of material from the subsurface. The formation of these jets could be produced by the sublimation of ice (temperatures below 273 K) rising beneath the hydrostatic pressure along the ice layer or can come from underground boiling liquid that erupts through vents. Other hypothesis assumes that there are regions where the pressure can drop below the saturation vapor pressure of the liquid, allowing for it to boil, so it can produce a pocket of gas in equilibrium with ice grains and liquid water. Another possibility is that the thermal activity in the seafloor of Enceladus creates hot water outflows that locally affect the ice shell and the thinner icy crust in the polar region due to tidal stress. This work presents another possible model for the formation of these vapor plumes. The hydro cyclonic flow could be also a mechanism that produces a constant ejection of these jets and contributes to atmospheric processes. Here we describe a simulation of the dynamic of the energy budget into the atmosphere. Enceladus is tidally locked with Saturn, making the moon spinning around the planet always showing the same face, generating in this way a difference in temperatures between the internal side and the external one. This contrast of temperatures might produce a movement of violent flows of jets on the equator similar to the storms observed on Jupiter. If the tidal axis is not aligned with the major axis, the tidal forces exert a net momentum on the moon, forcing a realignment of the orbit. The result of these processes is a hydro cyclonic flux in the shape of a tornado that eventually generates, due to pressure differences, a straight upwards constant flow that separates the fine particles rising towards the surface from the heavy ones sinking towards the ocean. This hydro cyclonic type of flow might explain the constant jets from the tiger stripes on Enceladus that could decrease when the energy flux received from the sun drops due to the distance between Saturn and the Sun, and the atmospheric and physical conditions are stable.

How to cite: Villavicencio Valero, K., Ramírez-Juidías, E., and Allemand, P.: Hydro cyclone flow as a physical process of ejection of material in the plumes of Enceladus and influence in the atmosphere., EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-1986, https://doi.org/10.5194/egusphere-egu22-1986, 2022.

09:15–09:21

EGU22-3808

ECS

On-site presentation

Dusty-Gas Simulations of Io's plumes

Lea Klaiber, Nicolas Thomas, and Raphael Marschall

Io is the innermost Galilean satellite of Jupiter and is the most volcanically active body

in our solar system. Its largest volcanic plumes can rise up to several hundred kilometers

above the surface. These volcanic plumes are one known source of Io's SO₂ atmosphere,

but additionally the surface of the moon is covered with surface frost which sublimates in

sunlight and condenses during the night and when Io enters eclipse behind Jupiter. There-

fore, Io's atmosphere is a result of the combination of volcanism and sublimation, but it is

unknown exactly how these processes work together to create the observed atmosphere. We

are investigating the flow of SO₂ gas from the source of a plume, into the umbrella-shaped

canopy, and eventually back onto the surface. Additionally, we also study the interaction of

the plumes with an ambient sublimation atmosphere. Both, the gas flow of the plume and

the sublimation atmosphere, are modelled using the Direct Simulation Monte Carlo (DSMC)

method first utilised by G.A.Bird. The DSMC method is the most suitable for this case

because the gas dynamics can be modeled over a great range of gas densities which is es-

pecially important for rarefied gas flows at high altitudes and on the night side of Io. Our

DSMC code is multi-species and also allows the simulation of gas emission from lava lakes

that may also contribution to the atmosphere. Finally, we are also able to implement dust

particles in the plume and analyse the effect for different dust sizes. Our goal is to gain a

better understanding of the plume structure, the interaction with the ambient atmosphere

and the overall contribution of different processes to Io's atmosphere in preparation for future

missions such as JUICE, Europa Clipper and a possible future Io Volcano Observer.

How to cite: Klaiber, L., Thomas, N., and Marschall, R.: Dusty-Gas Simulations of Io's plumes, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3808, https://doi.org/10.5194/egusphere-egu22-3808, 2022.

09:21–09:27

EGU22-4995

On-site presentation

Studying the ejection of particles for realistic Mercury analog samples upon He impact

Herbert Biber, Paul Stefan Szabo, Noah Jäggi, Johannes Brötzner, Christian Cupak, Benjamin Cserveny, Caroline Voith, Andrè Galli, Peter Wurz, and Friedrich Aumayr

The interaction between solar wind ions and the surface of rocky bodies leads to the release of material. This process of material ejection called ion sputtering contributes signiﬁcantly to the formation of Mercury’s exosphere [1]. Building a quantitative understanding on how ions interact with the complex system that a rocky body represents is therefore a crucial task for correctly modeling the exosphere of Mercury. Speciﬁcally, the number of sputtered atoms as well as the distributions of emission angles and energies are of interest. Common codes that are able to calculate these quantities are based on Molecular Dynamics (MD) or the Binary Collision Approximation (BCA). The former are complex and computationally demanding but can yield precise results when set up correctly. The latter are much simpler and faster in their usage but require input parameters, which have to be carefully chosen to correctly describe experimental results [2]. The angular motion setup for sputtering measurements at TU Wien allows to perform experiments required to validate MD and BCA results for various types of ions and samples [3]. We will present sputter yields and distributions of sputtered particles for 4 keV He ions impinging the Mercury-relevant pyroxene enstatite (MgSiO₃). In addition to the results obtained from irradiating amorphous thin ﬁlms we show and discuss yields from pressed mineral pellets [4]. We thereby extend on typical approaches, where only thin ﬁlms are investigated for their sputtering behavior under ion impingement [2, 5]. This information will lead to a better understanding of exosphere formation through particles released by solar wind interaction from the surfaces of Mercury and other exposed planetary bodies.

References

[1]   Wurz P., et al.: Planet. Space Sci., 58, 1599, 2010.
[2]   Szabo P. S., et al.: Astrophys. J., 891, 100, 2020.
[3]   Biber H., et al.: EPSC2021, online, EPSC2021-526, 2021.
[4]   Jäggi N., et al.: Icarus, 365, 114492, 2021.
[5]   Hijazi H., et al.: J. Geophys. Res. Planets, 122, 1597, 2017.

How to cite: Biber, H., Szabo, P. S., Jäggi, N., Brötzner, J., Cupak, C., Cserveny, B., Voith, C., Galli, A., Wurz, P., and Aumayr, F.: Studying the ejection of particles for realistic Mercury analog samples upon He impact, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4995, https://doi.org/10.5194/egusphere-egu22-4995, 2022.

09:27–09:33

EGU22-5188

ECS

On-site presentation

An update on modeled ion sputter yields of planetary bodies in agreement with recent experimental data

Noah Jäggi, Herbert Biber, Paul Stefan Szabo, Audrey Vorburger, Andreas Mutzke, Friedrich Aumayr, Peter Wurz, and André Galli

Thin, collisionless atmospheres are created around otherwise atmosphere-free celestial bodies through space weathering processes. Impinging solar wind ions eject highly energetic particles into these atmospheres by sputtering. Some ejected particles escape from the atmosphere, some return to the surface or are ionized and might be caught in a surrounding magnetosphere or the solar wind plasma. This process can be observed far into space through ground based and in-situ observations.

Determining the sputter yield of the various species from a realistic mineral surface is still a work in progress [1]. Modeling of sputtering with commonly used Binary Collision Approximation (BCA) models such as TRIM [2] has been shown to overestimate the sputter yields compared to experimental data [3, 4]. The number of sputter experiments performed on rock forming minerals is growing steadily, however. We apply the latest findings to obtain yields for a range of minerals from the state-of-the-art model SDTrimSP [5], which is based on TRIM.

To obtain yields of surface compositions of rocky bodies we present an approximation through weighing each mineral’s sputter yield contribution. This improves upon the simplification of assuming a bulk surface composition with TRIM and the resulting overestimated sputter yields. Simulating each mineral separately with SDTrimSP and considering the current knowledge on sputter behavior is tedious and requires extensive computing power. For this reason, we develop a database of sputter yields for important rock-forming minerals allowing easy access for researchers on which we will show our progress.

[1] Jäggi, N., et al. (2021). Icarus, 365, 114492.

[2] Ziegler, J.F., et al. (2010). Nucl. Instrum. Methods Phys. Res. B, 268, 1818–1823.

[3] Biber H., et al. (2020). Nucl. Instrum. Methods Phys. Res. B, 480, 10.

[4] Szabo, P.S., et al. (2018). Icarus, 314, 98–105.

[5] Mutzke, A., et al. (2019). SDTrimSP Version 6.00. Max-Planck-Institut für Plasmaphysik.

How to cite: Jäggi, N., Biber, H., Szabo, P. S., Vorburger, A., Mutzke, A., Aumayr, F., Wurz, P., and Galli, A.: An update on modeled ion sputter yields of planetary bodies in agreement with recent experimental data, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5188, https://doi.org/10.5194/egusphere-egu22-5188, 2022.

09:33–09:39

EGU22-5236

ECS

On-site presentation

An optimised Quartz Crystal Microbalance setup to investigate the sputtering behaviour of bulk targets

Johannes Brötzner, Herbert Biber, Paul Stefan Szabo, Noah Jäggi, Christian Cupak, Benjamin Cserveny, Caroline Voith, André Galli, Peter Wurz, and Friedrich Aumayr

In modelling the exosphere formation of atmosphere-less planetary objects [1], the sputtering contributions is often calculated using Monte-Carlo style simulations like SRIM [2]. However, input parameters of these codes often need to be adapted to successfully describe experimental data [3].

To provide such experimental data, we perform sputter measurements in which we irradiate mineral samples relevant for modelling the surfaces of Mercury or the Moon. Usually, such experiments are performed using thin sample films deposited onto a Quartz Crystal Microbalance (QCM), allowing to determine mass changes in real time and in situ [4, 5]. Advancing on this technique, we conduct measurements using a previously presented setup with a second QCM facing the irradiated samples [6]. It collects particles liberated by sputtering and probes their angular distribution. This setup allows for experiments with bulk samples, including pellets made of mineral powders [7]. These are currently being used in addition to the aforementioned thin films on primary QCMs. The goal with these samples is to detect possible differences in sputtering behaviour between the amorphous films and the bulk specimens that might be explained by crystallinity [8].

Experiments with such an advanced setup require an optimisation of the measurement procedure. Due to the high sensitivity of the QCM technique, small fluctuations in the experimental conditions can lead to noticeably different catcher signals. We therefore adapted the setup geometry to ensure constant relative distances between all specimens. Additionally, sample preparation cycles were changed to minimise transient effects on the QCMs which can be caused by non-equilibrium sticking on the catcher QCM. Furthermore, data evaluation was adapted to focus on relative changes from thin film to pellet measurements, rather than absolute signals. We immediately irradiate both types of samples after each other at a fixed catcher angle. This allows us to neglect long-term changes in experimentation parameters at this chosen position. Using these procedures, we can reliably reproduce irradiation results. We are therefore capable of precisely measuring sputtering yields and angular distributions of atoms sputtered by solar wind ions for bulk samples.

References

[1] Wurz P., et al.: Icarus, 191, 486, 2007.

[2] Ziegler, J. F., et al.: Nucl Instrum Methods Phys Res B, 268, 1818, 2010.

[3] Schaible, M. J., et al.: J. Geophys. Res. Planets, 122, 1968, 2017.

[4] Hayderer G., et al.: Rev. Sci. Instrum., 70, 3696, 1999.

[5] Szabo P. S., et al.: Icarus, 314, 98, 2018.

[6] Biber H., et al.: EPSC2021, online, EPSC2021-526, 2021.

[7] Jäggi N., et al.: Icarus, 365, 114492, 2021.

[8] Schlueter, K., et al.: Phys. Rev. Lett., 125.22, 225502, 2020.

How to cite: Brötzner, J., Biber, H., Szabo, P. S., Jäggi, N., Cupak, C., Cserveny, B., Voith, C., Galli, A., Wurz, P., and Aumayr, F.: An optimised Quartz Crystal Microbalance setup to investigate the sputtering behaviour of bulk targets, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5236, https://doi.org/10.5194/egusphere-egu22-5236, 2022.

Exoplanets

09:39–09:45

EGU22-4974

On-site presentation

Dust in brown dwarfs and extra-solar planets -3D Monte Carlo versus kinetic approach of TiO2 seed formation

Martin Bødker Enghoff, Christoph Köhn, Christiane Helling, Dan Krog, David Gobrecht, Jan Philip Sindel, and Kirsty Haynes

Modelling the formation of cloud condensation nuclei is key for predicting cloud properties in and analyzing observational data from exoplanet and brown dwarf atmospheres. Based on kinetic results on cloud formation in exoplanets, we readdress the question about the formation of cloud condensation nuclei through a Monte Carlo approach. We tackle the formation of TiO₂ clusters using a recently developed particle code in 3D. We initiate 1000 TiO₂ molecules in a domain of 1 cm³ size. We trace individual particles and check after every time step whether particles collide and form larger clusters. We run simulations at temperatures between 500 K and 1500 K, with particle sticking probabilities between 0.1 and 1 and distinguish whether only monomers or all other clusters are allowed to stick to earlier formed clusters. We present the number densities, the size distributions and the formation rate of clusters of different size and compare our results with results from a kinetic approach.
Simulating the motion of individual clusters allows us to display the spatial distribution of all particles as well as to determine their mean and maximum size. We calculate the line opacities of (TiO₂)_N clusters and discuss their detectability through the James Webb Space Telescope or the upcoming Extremely Large Telescope. Our results present a first step towards a better understanding of the formation of cloud formation nuclei in extrasolar environments by comparing selected results from molecular dynamic simulations with a kinetic approach based on thermodynamic cluster data.

How to cite: Enghoff, M. B., Köhn, C., Helling, C., Krog, D., Gobrecht, D., Sindel, J. P., and Haynes, K.: Dust in brown dwarfs and extra-solar planets -3D Monte Carlo versus kinetic approach of TiO2 seed formation, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4974, https://doi.org/10.5194/egusphere-egu22-4974, 2022.

09:45–09:51

EGU22-8125

ECS

On-site presentation

Study of the runaway greenhouse effect with a 3D global climate model

Guillaume Chaverot, Emeline Bolmont, and Martin Turbet

The runaway greenhouse effect [1-4] is a very interesting process for terrestrial planets, studied in particular to determine the inner limit of the Habitable Zone (HZ). This limit is usually defined via the calculation of the asymptotic limit of thermal emission of the planet (OLR = Outgoing Longwave Radiation), also called Simpson-Nakajima limit. We have recently shown, using a 1D radiative-convective model, that a radiatively inactive gas such as nitrogen (N₂) strongly modifies the OLR of the atmosphere [5] and can extend the inner edge of the HZ towards the host star [6]. We have also highlighted the importance of some physical processes sometimes considered as second order processes (e.g., collisional broadening of water lines).

In continuation of this work, we use a 3D global climate model, LMD-Generic, to study the onset of the runaway greenhouse for similar atmospheres. Some studies have shown that evaporation can lead to a moist stable state [7, 8], while others suggest an inevitable runaway greenhouse effect [9].

Here, we re-explore these possible moist stable states to better understand the key physical processes that potentially lead an Earth-like planet to a surface warming of several thousand degrees. We compare the results from 3D and 1D simulations, based on the conclusions of our previous study [5], in order to better understand the contribution of each process with a focus on clouds and dynamics, which are inherently three-dimensional processes.

References

[1] Komabayasi, M. 1967, Journal of the Meteorological Society of Japan. Ser. II

[2] Ingersoll, A. 1969, Journal of the Atmospheric Sciences

[3] Nakajima, S., Hayashi, Y.-Y., & Abe, Y. 1992, Journal of the Atmospheric Sciences

[4] Goldblatt, C. & Watson, A. J. 2012, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences

[5] Chaverot G., Bolmont, E., Turbet, M., Leconte, J. 2021, Astronomy & Astrophysics

[6] Goldblatt, C., Robinson, T. D., Zahnle, K. J., & Crisp, D. 2013, Nature Geoscience

[7] Wolf, E. T., Toon, O. B. 2015, Journal of Geophysical Research

[8] Pop, M., Schmidt, H., Marotzke, J. 2016, Nature Communications

[9] Leconte, J., Forget, F., Charnay, B. et al., 2013, Nature

How to cite: Chaverot, G., Bolmont, E., and Turbet, M.: Study of the runaway greenhouse effect with a 3D global climate model, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8125, https://doi.org/10.5194/egusphere-egu22-8125, 2022.

09:51–09:57

EGU22-8185

ECS

Virtual presentation

3D Climate modelling of TRAPPIST-1 c with a Venus-like atmosphere: large-scale circulation and observational prospects

Diogo Quirino, Gabriella Gilli, Thomas Navarro, Martin Turbet, Thomas Fauchez, and Pedro Machado

In recent years, several Earth-sized exoplanets have been detected in short-period orbits of a few Earth days, around low-mass stars [1]. Despite their small size compared to gas giants, their close-in orbits combined with the small radius of the host star compared to our Sun’s make these worlds the best targets for atmospheric characterisation among rocky exoplanets. These worlds have stellar irradiation levels that can be several times that of the Earth, suggesting that a Venus-like climate is more likely [2]. Thus, the atmosphere of our neighbouring planet Venus presents a relevant case to address observational prospects.

The recent launch of the James Webb Space Telescope will advance the atmosphere and climate characterisation of nearby rocky exoplanets, with the support of upcoming ground-based observatories and space telescopes, such as the ESA/Ariel mission, scheduled for launch in 2029. The interpretation of the observables produced by these missions: reflectance, thermal emission and transmission spectra will need support from modelling studies of exoplanetary atmospheres. In particular, 3D Global Climate Models (GCMs) are critical for interpreting the observable signal’s modulations, as they provide synthetic top-of-the-atmosphere fluxes that can be disk-integrated as a function of the orbital phase. The spatial and temporal variability of these fluxes reflect the atmospheric variability of the simulated temperature and wind fields and provide insight over the large-scale circulation.

In this work, we used the Generic-GCM, developed at the Laboratoire de Météorologie Dynamique for exoplanet and paleoclimate studies [3, 4, 5], which includes a 3D dynamical core, common to all terrestrial planets, a planet-specific physical core, and an up-to-date generalised radiative transfer routine for variable atmospheric compositions.

We present the results of modelling highly irradiated rocky exoplanets orbiting an M-dwarf star, using a Venus-like atmosphere as a possible framework for the atmospheric conditions of TRAPPIST-1 c. We assumed synchronous rotation, zero eccentricity and obliquity, and a Venus-like atmosphere with 92-bar surface pressure and a radiatively active Venus-type global cloud cover. The results indicate an eastward shift of the peak thermal emission away from the sub-stellar point, suggesting an advection of warm air masses caused by a superrotation equatorial jet.

References:

[1] Gillon et al. 2017. Nature. 542.

[2] Kane et al. 2018. ApJ. 869.

[3] Forget & Leconte, 2014. Phil. Trans R. Soc. A372.

[4] Turbet et al. 2016. A&A. 596. A112.

[5] Wordsworth et al. 2011. ApJL. 733. L48.

Acknowledgements:

This work is supported by Fundação para a Ciência e a Tecnologia (FCT) through the research grants UIDB/04434/2020, UIDP/04434/2020, P-TUGA PTDC/FIS-AST/29942/2017.

How to cite: Quirino, D., Gilli, G., Navarro, T., Turbet, M., Fauchez, T., and Machado, P.: 3D Climate modelling of TRAPPIST-1 c with a Venus-like atmosphere: large-scale circulation and observational prospects, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8185, https://doi.org/10.5194/egusphere-egu22-8185, 2022.