scholarly journals Bursty ion escape fluxes at Mars

2021 ◽  
Author(s):  
E. Dubinin ◽  
M. Fraenz ◽  
M. Pätzold ◽  
S. Tellmann ◽  
J. Woch ◽  
...  
Keyword(s):  
Ion Escape

scholarly journals Solar cycle variation of ion escape from Mars

Icarus ◽  
2021 ◽  
pp. 114610
Author(s):  
Hans Nilsson ◽  
Qi Zhang ◽  
Gabriella Stenberg Wieser ◽  
Mats Holmström ◽  
Stas Barabash ◽  
...  
Keyword(s):  
Solar Cycle ◽  
Solar Cycle Variation ◽  
Cycle Variation ◽  
Ion Escape

scholarly journals Mars Under Primordial Solar Wind Conditions: Mars Express Observations of the Strongest CME Detected at Mars Under Solar Cycle #24 and its Impact on Atmospheric Ion Escape

2017 ◽  
Vol 44 (21) ◽  
Author(s):  
Robin Ramstad ◽  
Stas Barabash ◽  
Yoshifumi Futaana ◽  
Masatoshi Yamauchi ◽  
Hans Nilsson ◽  
...  
Keyword(s):  
Solar Wind ◽  
Solar Cycle ◽  
Mars Express ◽  
Ion Escape ◽  
Solar Cycle 24 ◽  
Cycle 24

Hybrid simulation study of ion escape at Titan for different orbital positions

2006 ◽  
Vol 38 (4) ◽  
pp. 799-805 ◽  
Author(s):  
I. Sillanpää ◽  
E. Kallio ◽  
P. Janhunen ◽  
W. Schmidt ◽  
K. Mursula ◽  
...  
Keyword(s):  
Simulation Study ◽  
Hybrid Simulation ◽  
Ion Escape

How atmospheric escape sculped the evolution of the Martian CO2 atmosphere over time

2021 ◽  
Author(s):  
Manuel Scherf ◽  
Herbert Lichtenegger ◽  
Sergey Dyadechkin ◽  
Helmut Lammer ◽  
Raven Adam ◽  
...  
Keyword(s):  
Numerical Models ◽  
Atmospheric Escape ◽  
Ion Escape ◽  
Thermal Escape ◽  
Partial Pressures ◽  
Argon Isotopes ◽  
Atmospheric Loss ◽  
4.1 Ga ◽  
Insight Into ◽  
Volcanic Outgassing

<p>Mars likely had a denser atmosphere during the Noachian eon about 3.6 to 4.0 billion years ago (Ga). How dense this atmosphere might have been, and which escape mechanisms dominated its loss are yet not entirely clear. However, non-thermal escape processes and potential sequestration into the ground are believed to be the main drivers for atmospheric loss from the present to about 4.1 Ga.</p> <p>To evaluate non-thermal escape over the last ~4.1 billion years, we simulated the ion escape of Mars' CO<sub>2</sub> atmosphere caused by its dissociation products C and O atoms with numerical models of the upper atmosphere and its interaction with the solar wind (see Lichtenegger et al. 2021; https://arxiv.org/abs/2105.09789). We use the planetward-scattered pick-up ions for sputtering estimates of exospheric particles including <sup>36</sup>Ar and <sup>38</sup>Ar isotopes, and compare ion escape, with sputtering and photochemical escape rates. For solar EUV fluxes ≥3 times the present-day Sun (earlier than ~2.6 Ga) ion escape becomes the dominant atmospheric non-thermal loss process until thermal escape takes over during the pre-Noachian eon (earlier than ~4.0 - 4.1 Ga). If we extrapolate the total escape of CO<sub>2</sub>-related dissociation products back in time until ~4.1 Ga, we obtain a theoretical equivalent to CO<sub>2</sub> partial pressure of more than ~3 bar, but this amount did not necessarily have to be present and represents a maximum that could have been lost to space within the last ~4.1 Ga.</p> <p>Argon isotopes can give an additional insight into the evolution of the Martian atmosphere. The fractionation of <sup>36</sup>Ar/<sup>38</sup>Ar isotopes through sputtering and volcanic outgassing from its initial chondritic value of 5.3, as measured in the 4.1 billion years old Mars meteorite ALH 84001, until the present day can be reproduced for assumed CO<sub>2</sub> partial pressures between ~0.2-3.0 bar, depending on the cessation time of the Martian dynamo (assumed between 3.6-4.0 Ga) - if atmospheric sputtering of Ar started afterwards. The later the dynamo ceased away, the lower the pressure could have been to reproduce <sup>36</sup>Ar/<sup>38</sup>Ar.</p> <p>Prior to ~4.1 Ga (i.e., during the pre-Noachian eon), thermal escape should have been the most important driver of atmospheric escape at Mars, and together with non-thermal losses, might have prevented a stable and dense CO<sub>2</sub> atmosphere during the first ~400 million years. Our results indicate that, while Mars could have been warm and wet at least sporadically between ~3.6-4.1 Ga, it likely has been cold and dry during the pre-Noachian eon (see also Scherf and Lammer 2021; https://arxiv.org/abs/2102.05976).</p>

scholarly journals Stellar wind interaction and pick-up ion escape of the Kepler-11 “super-Earths”

2014 ◽  
Vol 562 ◽  
pp. A116 ◽  
Author(s):  
K. G. Kislyakova ◽  
C. P. Johnstone ◽  
P. Odert ◽  
N. V. Erkaev ◽  
H. Lammer ◽  
...  
Keyword(s):  
Stellar Wind ◽  
Ion Escape

scholarly journals Planetary magnetic field control of ion escape from weakly magnetized planets

2019 ◽  
Vol 488 (2) ◽  
pp. 2108-2120 ◽  
Author(s):  
Hilary Egan ◽  
Riku Jarvinen ◽  
Yingjuan Ma ◽  
David Brain
Keyword(s):  
Magnetic Field ◽  
Effective Interaction ◽  
Three Dimensional ◽  
Power Laws ◽  
Wind Pressure ◽  
Escape Rate ◽  
Opening Angle ◽  
Plasma Environment ◽  
Ion Escape ◽  
Planetary Magnetic Field

ABSTRACT Intrinsic magnetic fields have long been thought to shield planets from atmospheric erosion via stellar winds; however, the influence of the plasma environment on atmospheric escape is complex. Here we study the influence of a weak intrinsic dipolar planetary magnetic field on the plasma environment and subsequent ion escape from a Mars-sized planet in a global three-dimensional hybrid simulation. We find that increasing the strength of a planet’s magnetic field enhances ion escape until the magnetic dipole’s standoff distance reaches the induced magnetosphere boundary. After this point increasing the planetary magnetic field begins to inhibit ion escape. This reflects a balance between shielding of the Southern hemisphere from ‘misaligned’ ion pickup forces and trapping of escaping ions by an equatorial plasmasphere. Thus, the planetary magnetic field associated with the peak ion escape rate is critically dependent on the stellar wind pressure. Where possible we have fit power laws for the variation of fundamental parameters (escape rate, escape power, polar cap opening angle, and effective interaction area) with magnetic field, and assessed upper and lower limits for the relationships.

scholarly journals Ion escape from the upper ionosphere of Titan triggered by the solar wind

2019 ◽  
Vol 364 (9) ◽  
Author(s):  
W. M. Moslem ◽  
S. Salem ◽  
R. Sabry ◽  
M. Lazar ◽  
R. E. Tolba ◽  
...  
Keyword(s):  
Solar Wind ◽  
Ion Escape ◽  
Upper Ionosphere

Modulation of the solar wind driven ion escape from unmagnetized planets by ultra-low-frequency foreshock waves in a global hybrid simulation

2020 ◽  
Author(s):  
Riku Jarvinen ◽  
Esa Kallio ◽  
Tuija Pulkkinen
Keyword(s):  
Solar Wind ◽  
Large Scale ◽  
Low Frequency ◽  
Hybrid Simulation ◽  
Bow Shock ◽  
Upstream Region ◽  
Ulf Waves ◽  
Solar Wind Interaction ◽  
Ion Escape ◽  
A Charge

<p>We study the solar wind interaction with Venus in a 3-dimensional global hybrid model where ions are treated as particles and electrons are a charge-neutralizing fluid. We concentrate on large-scale ultra-low frequency (ULF) waves in the ion foreshock and how they affect the energization and escape of planetary ions. The ion foreshock forms in the upstream region ahead of the quasi-parallel bow shock, where the angle between the shock normal and the magnetic field is smaller than about 45 degrees. The magnetic connection with the bow shock allows backstreaming of the solar wind ions leading to the formation of the ion foreshock. This kind of beam-plasma configuration is a source of free energy for the excitation of plasma waves. The foreshock ULF waves convect downstream with the solar wind flow and encounter the bow shock and transmit in the downstream region. We analyze the coupling of the ULF waves with the planetary ion acceleration and compare Venus and Mars in a global hybrid simulation.</p>

scholarly journals Effects of the crustal magnetic fields on the Martian atmospheric ion escape rate

2016 ◽  
Vol 43 (20) ◽  
pp. 10,574-10,579 ◽  
Author(s):  
Robin Ramstad ◽  
Stas Barabash ◽  
Yoshifumi Futaana ◽  
Hans Nilsson ◽  
Mats Holmström
Keyword(s):  
Magnetic Fields ◽  
Escape Rate ◽  
Ion Escape
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