The structure of Mars lower atmosphere from Mars Express Radio Science (MaRS) occultation measurements

2013 ◽  
Vol 118 (2) ◽  
pp. 306-320 ◽  
Author(s):  
Silvia Tellmann ◽  
Martin Pätzold ◽  
Bernd Häusler ◽  
D. P. Hinson ◽  
G. Leonard Tyler
Keyword(s):  
Lower Atmosphere ◽  
Mars Express ◽  
Radio Science

Sulfuric acid vapor and sulfur dioxide in the atmosphere of Venus as observed by the Venus Express Radio Science Experiment VeRa

2021 ◽  
Author(s):  
Janusz Oschlisniok ◽  
Bernd Häusler ◽  
Martin Pätzold ◽  
Silvia Tellmann ◽  
Michael Bird
Keyword(s):  
Sulfuric Acid ◽  
Transport Model ◽  
Lower Atmosphere ◽  
Local Times ◽  
Acid Vapor ◽  
Radio Science ◽  
X Band ◽  
Wide Range ◽  
Venus Express ◽  
Atmosphere Of Venus

<p>The main cloud deck within Venus' atmosphere, which covers the entire planet between approx. 50 and 70 km altitude, is believed to consist mostly of liquid sulfuric acid. The temperature below the main clouds is high enough to evaporate the H2SO4 droplets into gaseous sulfuric acid forming a haze layer which extends to altitudes as deep as 35 km. Gaseous sulfuric acid in Venus’ lower atmosphere is responsible for a strong absorption of radio waves as seen in Mariner, Pioneer Venus, Magellan and Venera radio science observations. Radio wave absorption measurements can be used to derive the amount of H2SO4 in Venus’ atmosphere. The radio science experiment VeRa onboard Venus Express probed the atmosphere of Venus between 2006 and 2014 with radio signals at 13 cm (S-band) and 3.6 cm (X-band) wavelengths. The orbit of the Venus Express spacecraft allowed to sound the atmosphere over a wide range of latitudes and local times providing a global picture of the sulfuric acid vapor distribution. We present the global H2SO4(g) distribution derived from the X-band radio signal attenuation for the time of the entire Venus Express mission. The observation is compared with results obtained from a 2-D transport model. The VeRa observations were additionally used to estimate the abundance of SO2 near the cloud bottom. The global distribution of SO2 at these altitudes is presented and compared with results obtained from other experiments. Eight years of VEX observation allow to study the long-term evolution of H2SO4 and SO2. The latter is presented for the northern polar region.</p>

scholarly journals Observations of the nightside ionosphere of Mars by the Mars Express Radio Science Experiment (MaRS)

2012 ◽  
Vol 117 (A12) ◽  
pp. n/a-n/a ◽  
Author(s):  
Paul Withers ◽  
M. O. Fillingim ◽  
R. J. Lillis ◽  
B. Häusler ◽  
D. P. Hinson ◽  
...  
Keyword(s):  
Mars Express ◽  
Radio Science

A Sporadic Third Layer in the Ionosphere of Mars

Science ◽  
2005 ◽  
Vol 310 (5749) ◽  
pp. 837-839 ◽  
Author(s):  
M. Pätzold ◽  
S. Tellmann ◽  
B. Häusler ◽  
D. Hinson ◽  
R. Schaa ◽  
...  
Keyword(s):  
Electron Density ◽  
Charge Exchange ◽  
Layer Structure ◽  
Electron Densities ◽  
Ionospheric Layer ◽  
Density Profiles ◽  
Mars Express ◽  
Radio Science ◽  
Martian Ionosphere ◽  
Electron Density Profiles

The daytime martian ionosphere has been observed as a two-layer structure with electron densities that peak at altitudes between about 110 and 130 kilometers. The Mars Express Orbiter Radio Science Experiment on the European Mars Express spacecraft observed, in 10 out of 120 electron density profiles, a third ionospheric layer at altitude ranges of 65 to 110 kilometers, where electron densities, on average, peaked at 0.8 × 1010 per cubic meter. Such a layer has been predicted to be permanent and continuous. Its origin has been attributed to ablation of meteors and charge exchange of magnesium and iron. Our observations imply that this layer is present sporadically and locally.

Dynamical phenomena in the atmosphere of Mars imaged with the Visual Monitoring Camera onboard Mars Express

2020 ◽  
Author(s):  
Teresa del Río-Gaztelurrutia ◽  
Agustín Sánchez-Lavega ◽  
Jorge Hernández-Bernal ◽  
Ricardo Hueso ◽  
Alejandro Cardesín-Moinelo ◽  
...  
Keyword(s):  
Gravity Waves ◽  
Dust Storms ◽  
Lower Atmosphere ◽  
Temperature Fields ◽  
Polar Regions ◽  
Storm Activity ◽  
Visual Monitoring ◽  
Mars Express ◽  
Wide Range ◽  
Monitoring Camera

<p>The Visual Monitoring Camera on board Mars Express provides images of varied resolutions, covering a wide range of locations and seasons, and has been taking images for several Martian years. This large image database can be exploited to study various dynamical phenomena, and in this work, we concentrate on the study of cloud and dust storm activity in the polar regions, describing vortices, cloud evolution, and regional dust storms as well as the presence of gravity waves. Tracking the motions of details in the images, we estimate local winds, compare our results with predictions from the Mars Climate Database in different scenari, and study their seasonal evolution and potential inter annual variability. Further, resolution of images captured near pericenter is sufficient to allow the detection of gravity waves in the troposphere, identified as regular patterns in the cloud fields. We measure some of the basic properties of these waves, such as horizontal wave vector and extension of wave trains. We analyse those properties in relation to their aerographic location, local time and season, in the context of a recent study of the distribution of gravity waves on the lower atmosphere of Mars as inferred from the analysis of temperature fields by the Mars Climate Sounder onboard the Mars Reconnaissance Orbiter (MRO) (Heavens et al. ICARUS 2020).</p>

scholarly journals Retrieval of ionospheric profiles from the Mars Express MARSIS experiment data and comparison with radio-occultation data

2012 ◽  
Vol 2 (1) ◽  
pp. 87-106
Author(s):  
B. Sánchez-Cano ◽  
O. Witasse ◽  
M. Herraiz ◽  
S. M. Radicella ◽  
J. Bauer ◽  
...  
Keyword(s):  
Radio Occultation ◽  
European Space Agency ◽  
Planetary Science ◽  
Data Set ◽  
Mars Express ◽  
Radio Science ◽  
Space Agency ◽  
Martian Ionosphere ◽  
Occultation Data ◽  
Ionospheric Sounding

Abstract. Since 2005 the Mars Advanced Radar and Ionospheric Sounding experiment (MARSIS) aboard Mars Express has acquired a unique data set on the ionosphere of Mars made up of ionospheric soundings taken by the instrument working in its Active Ionospheric Sounding (AIS) mode. These soundings play a role similar to those of modern Terrestrial digisondes in the analysis of our planet ionosphere and have allowed us to dramatically improve our knowledge about the Martian ionosphere. This paper describes this kind of data, which are available from the public Planetary Science Archive, and introduces the MAISDAT tool developed by the European Space Agency to analyze and derive the vertical profile of electron density. Comparisons with radio-occultation profiles obtained from Mars Express Radio Science instrument are performed to validate the procedure used in this study.

scholarly journals Retrieval of ionospheric profiles from the Mars Express MARSIS experiment data and comparison with radio occultation data

2012 ◽  
Vol 1 (1) ◽  
pp. 77-84 ◽  
Author(s):  
B. Sánchez-Cano ◽  
O. Witasse ◽  
M. Herraiz ◽  
S. M. Radicella ◽  
J. Bauer ◽  
...  
Keyword(s):  
Radio Occultation ◽  
European Space Agency ◽  
Planetary Science ◽  
Mars Express ◽  
Radio Science ◽  
The Public ◽  
Space Agency ◽  
Martian Ionosphere ◽  
Occultation Data ◽  
Ionospheric Sounding

Abstract. Since 2005 the Mars Advanced Radar and Ionospheric Sounding experiment (MARSIS) aboard Mars Express has acquired a unique dataset on the ionosphere of Mars made up of ionospheric soundings taken by the instrument working in its active ionospheric sounding (AIS) mode. These soundings play a role similar to those of modern Terrestrial digisondes in the analysis of our planet ionosphere and have allowed us to dramatically improve our knowledge about the Martian ionosphere. This paper describes this kind of data, which are available from the public Planetary Science Archive, and introduces the MAISDAT tool developed by the European Space Agency to analyze and derive the vertical profile of electron density. Comparisons with radio occultation profiles obtained from Mars Express Radio Science instrument are performed to validate the procedure used in this study.

The lower dayside ionosphere of Mars in light of MEX MaRS radio science observations

2020 ◽  
Author(s):  
Kerstin Peter ◽  
Martin Pätzold ◽  
Gregorio Molina-Cuberos ◽  
Francisco González-Galindo ◽  
Olivier Witasse ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Electron Density ◽  
Impact Ionization ◽  
Extreme Ultraviolet ◽  
Main Peak ◽  
X Rays ◽  
Mars Atmosphere ◽  
Mars Express ◽  
Radio Science ◽  
The Individual

<p>   <img src="https://contentmanager.copernicus.org/fileStorageProxy.php?f=gepj.a4004f2be2fe53228792951/sdaolpUECMynit/0202CSPE&app=m&a=0&c=0c4e6952561399e83d88c4d43fe544f2&ct=x&pn=gepj.elif" alt="">      <img src="https://contentmanager.copernicus.org/fileStorageProxy.php?f=gepj.7660ec3be2fe56328792951/sdaolpUECMynit/0202CSPE&app=m&a=0&c=0b6ac6aff35b94d80887605627a854c0&ct=x&pn=gepj.elif" alt=""></p><p><strong>Figure 1: MEX-MaRS X-band observations of the dayside ionosphere of Mars for (a) Day of Year (DoY) 343 (2005) and (b) DoY 215 (2014).  Combined X- and S-band (differential Doppler) observations for (c) DoY 011 (2014) and (d) DoY 006 (2006). The gray dashed line indicates the noise level, while the black dashed line marks the lowest valid altitude of the individual observation (details about the parameter derivation in [2]).</strong></p><p>The Mars Express Radio Science experiment (MaRS) on board the Mars Express spacecraft has observed the Mars atmosphere and ionosphere since 2004. More than 900 high-resolution MaRS height profiles of the ionospheric electron density from the topside down to the ionospheric base are available.</p><p>The two dominant features of the undisturbed Martian dayside ionosphere are the main peak (M2), caused mainly by solar radiation in the Extreme Ultraviolet, and the secondary layer (M1), mostly formed by primary and secondary impact ionization of short solar X-rays < 10 nm [1]. The region below the M1 peak is highly variable and regularly contains merged excess electron density regions (Mm) in various shapes [2] (Figures 1).</p><p>More than 15 years of MaRS radio science observations are used to study the behavior of the lowest region of the Martian dayside ionosphere. Categories for the identified Mm shapes are defined and statistics of the individual Mm shape occurrences are provided. The 1-D photochemical model IonA-2 (Ionization in Atmospheres 2 [2]) is applied to investigate which of the identified Mm shapes can be reproduced by solar radiation of the quiet Sun and under solar M- and X-flare conditions.</p><p> </p><p>References</p><p>  [1] Fox J. L. et al. (1996), Adv. Space Res., 17, 11, 203-218.</p><p>  [2] Peter K. (2018), PhD Dissertation, https://kups.ub.uni-koeln.de/8110/.</p>

scholarly journals MoMo: a new empirical model of the Mars ionospheric total electron content based on Mars Express MARSIS data

2019 ◽  
Vol 9 ◽  
pp. A36 ◽  
Author(s):  
Nicolas Bergeot ◽  
Olivier Witasse ◽  
Sébastien Le Maistre ◽  
Pierre-Louis Blelly ◽  
Wlodek Kofman ◽  
...  
Keyword(s):  
Total Electron Content ◽  
Empirical Model ◽  
Density Variation ◽  
Electron Content ◽  
Martian Surface ◽  
Total Electron ◽  
Mars Express ◽  
Radio Science ◽  
Ionosphere Model ◽  
The Impact

Aims: Several scientific landers and rovers have reached the Martian surface since the 1970s. Communication between the asset (i.e., lander or rover) and Mars orbiters or Earth antennas uses radio signals in UHF to X-band frequencies passing through the Mars’ ionosphere. It is consequently necessary to take into account electron density variation in the Mars’ ionosphere to correct the refraction of the signal transmitted. Methods: We developed a new empirical model of the Mars’ ionosphere called MoMo. It is based on the large database of Total Electron Content (TEC) derived from the subsurface mode of the Mars Express MARSIS radar. The model provides vertical TEC as a function of solar zenith angle, solar activity, solar longitude and location. For validation, the model is compared with Mars Express radio occultation data as well as with the numerical model IPIM (IRAP Plasmasphere-Ionosphere Model). Results: We discussed the output of the model in terms of climatology behaviour of the Mars’ ionosphere. The output of MoMo is then uses to quantify the impact of the Martian ionosphere for radio-science experiments. From our results, the effect is of the order of 10−3 mm s−1 in Doppler observables especially around sunrise and sunset. Consequently, this new model could be used to support the data analysis of any radio-science experiment and especially for present InSight RISE and futur ExoMars LARA instruments aiming at better understand the deep-interior of Mars.

The variability of the ionospheres of Mars and Venus derived from Mars Express and Venus Express radio science observations

2021 ◽  
Author(s):  
Kerstin Peter ◽  
Martin Pätzold ◽  
Feng Chu ◽  
Markus Fränz ◽  
Ed Thiemann ◽  
...  
Keyword(s):  
Mars Express ◽  
Radio Science ◽  
Venus Express
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