Aspera/Phobos measurements of the ion outflow from the MARTIAN ionosphere

Lundin, R.; Захаров, А. В.; Pellinen, R.; Barabasj, S. W.; Borg, H.; Dubinin, E.; Hultqvist, B.; Koskinen, H.; Liede, I.; Pissarenko, N. F.

doi:10.1029/gl017i006p00873

Cited by 186 publications

(129 citation statements)

References 9 publications

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“…Close to the planet, O + and O + 2 densities reach 4 cm −3 , while at 2-Martian radii these densities are still greater than 0.1 cm −3 at solar maximum. These simulated densities are comparable with Phobos-2 observations in the tail region where the O + density reaches 6 cm −3 (Lundin et al, 1989(Lundin et al, , 1990a. The difference between the densities of O + ions at the solar minimum and maximum can be explained by the fact that the oxygen neutral corona is denser and more extended at solar maximum.…”

Section: Solar Wind and Planetary Ionssupporting

confidence: 81%

“…On the other hand, photoionization is the main process which contributes to the escape of O + ions, which maximizes at solar maximum with the extension of oxygen corona. The loss rate of oxygen ions is about ten times smaller than the value given by Lundin et al (1990a) from the ASPERA measurements ( 2.5×10 25 ions/s) and is in better agreement with the estimates by Verigin et al (1991) equal to 5×10 24 ions/s from the TAUS measurements on board Phobos-2. The different assumptions made about the distribution of ion fluxes in the Martian tail explain this discrepancy between experimentals estimations.…”

Section: Estimation Of the Ionic Escapesupporting

confidence: 80%

“…On the basis of the Phobos-2 observations it was estimated that the total escape of the planetary matter at solar maximum can reach ∼1 kg/s (Lundin et al, 1990a). However, these estimates were made by using the in-situ plasma measurements and by assuming a cylindrical symmetry in the distribution of the outflowing ions.…”

Section: Estimation Of the Ionic Escapementioning

confidence: 99%

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Influence of the solar EUV flux on the Martian plasma environment

Modolo¹,

Chanteur²,

et al. 2005

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Abstract. The interaction of the solar wind with the Martian atmosphere and ionosphere is investigated by using threedimensional, global and multi-species hybrid simulations. In the present work we focus on the influence of the solar EUV flux on the Martian plasma environment by comparing simulations done for conditions representative of the extrema of the solar cycle. The dynamics of four ionic species (H + , He ++ , O + , O + 2 ), originating either from the solar wind or from the planetary plasma, is treated fully kinetically in the simulation model in order to characterize the distribution of each component of the plasma, both at solar maximum and at solar minimum. The solar EUV flux controls the ionization frequencies of the exospheric species, atomic hydrogen and oxygen, as well as the density, the temperature, and thus the extension of the exosphere. Ionization by photons and by electron impacts, and the main charge exchange reactions are self-consistently included in the simulation model. Simulation results are in reasonable agreement with the observations made by Phobos-2 and Mars Global Surveyor (MGS) spacecraft: 1) the interaction creates a cavity, void of solar wind ions (H + , He ++ ), which depends weakly upon the phase of the solar cycle, 2) the motional electric field of the solar wind flow creates strong asymmetries in the Martian environment, 3) the spatial distribution of the different components of the planetary plasma depends strongly upon the phase of the solar cycle. The fluxes of the escaping planetary ions are computed from the simulated data and results for solar maximum are compared with estimates based on the measurements made by experiments ASPERA and TAUS on board Phobos-2.

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Section: Solar Wind and Planetary Ionssupporting

confidence: 81%

Section: Estimation Of the Ionic Escapesupporting

confidence: 80%

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Influence of the solar EUV flux on the Martian plasma environment

Modolo¹,

Chanteur²,

et al. 2005

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“…At higher altitudes, the APP orientation is time shared between STATIC and the Imaging UltraViolet Spectrometer (IUVS, McClintock et al 2015). On orbits when STATIC has priority, the APP is oriented to optimize STATIC's ability to detect Martian pickup ions (Lundin et al 1990). MAVEN carries several other instruments with overlapping plasma sensitivity.…”

Section: Introductionmentioning

confidence: 99%

“…The MEX Ion Mass Analyzer (IMA) provided compositional information on losses, however, those measurements were generally limited by time resolution and by a lower energy cutoff (> 10 eV). Several estimates of total ion loss rates have been made (Lundin et al 1990;Carlsson et al 2006;Barabash et al 2007;Fang et al 2010;Ramstad et al 2013) with significant variations. The composition of escaping plasma measured with MEX IMA indicates comparable outflows of O+ and O 2 +, inferred by model fitting to the to the heavy ion mass peak.…”

Section: Introductionmentioning

confidence: 99%

MAVEN SupraThermal and Thermal Ion Compostion (STATIC) Instrument

et al. 2015

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The MAVEN SupraThermal And Thermal Ion Compostion (STATIC) instrument is designed to measure the ion composition and distribution function of the cold Martian ionosphere, the heated suprathermal tail of this plasma in the upper ionosphere, and the pickup ions accelerated by solar wind electric fields. STATIC operates over an energy range of 0.1 eV up to 30 keV, with a base time resolution of 4 seconds. The instrument consists of a toroidal "top hat" electrostatic analyzer with a 360• × 90• field-of-view, combined with a time-of-flight (TOF) velocity analyzer with 22.5• resolution in the detection plane. The TOF combines a −15 kV acceleration voltage with ultra-thin carbon foils to resolve H + , He ++ , He + , O + , O + 2 , and CO + 2 ions. Secondary electrons from carbon foils are detected by microchannel plate detectors and binned into a variety of data products with varying energy, mass, angle, and time resolution. To prevent detector saturation when measuring cold ram ions at periapsis (∼ 10 11 eV/cm 2 s sr eV), while maintaining adequate sensitivity to resolve tenuous pickup ions at apoapsis (∼ 10 3 eV/cm 2 s sr eV), the sensor includes both mechanical and electrostatic attenuators that increase the dynamic range by a factor of 10 3 . This paper describes the instrument hardware, including several innovative improvements over previous TOF sensors, the ground calibrations of the sensor, the data products generated by the experiment, and some early measurements during cruise phase to Mars.

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Solar cycle effects on the ion escape from Mars

Lundin

Barabash

Holmström

et al. 2013

Geophysical Research Letters

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Solar cycle effects on the escape of planetary ions from Mars are investigated using Mars Express Analyzer of Space Plasmas and Energetic Atoms 3 data from June 2007 to January 2013. Average and median tail fluxes of low‐energy (<300 eV) heavy ions (O+, O2+), derived from the full data set covering 7900 orbits, are highly correlated with the solar activity proxies F10.7 and the sunspot number, Ri. The average heavy ion escape rate increased by a factor of ≈ 10, from ≈ 1 · 1024 s−1 (solar minimum) to ≈ 1 · 1025 s−1 (solar maximum). Combining data from this, and other studies, an empiric model/expression is derived for the Martian escape rate versus solar activity F10.7 and Ri. The model is a useful tool to derive the accumulated ion escape rate from Mars based on historical records of solar activity, with potentials back to the young Sun époque.

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Aspera/Phobos measurements of the ion outflow from the MARTIAN ionosphere

Cited by 186 publications

References 9 publications

Influence of the solar EUV flux on the Martian plasma environment

Influence of the solar EUV flux on the Martian plasma environment

MAVEN SupraThermal and Thermal Ion Compostion (STATIC) Instrument

Solar cycle effects on the ion escape from Mars

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