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It is only recently that the periods during which the radars MARSIS and SHARAD are incapacitated, have been correlated to coronal mass ejections (CME) and solar energetic particles (SEP) events. MAVEN measurements of enhancements of the SEP electrons flux happen to be consistent with these radar blackouts. This phenomenon was attributed to an extra-ionization of the neutral atmosphere of Mars by the increased flux of SEP electrons, inducing an increase of the electron density which attenuates the radar signal. However, the effect of this phenomenon on the physical properties of the atmosphere was never observed as the instruments generally used, experienced blackouts. This study proposes the use of radio occultations to monitor the physical properties of the neutral Martian atmosphere during CME and SEP events as the radio signals used in this technique are not attenuated by the extra-ionization. The two case studies of this work suggest that CME/SEP events are correlated to a decrease of the upper atmosphere refractivity due to an increase of the electron density induced by an extra-ionization caused by the SEP electrons. An atmospheric disturbance is also observed during CME/SEP events further suggesting an extra-ionization of this same region. Our results are coherent with the MAVEN and MEX measurements of the SEP electrons as well as with MARSIS and SHARAD blackouts. This study presents the first global analysis of such modifications of the physical properties of the neutral atmosphere of Mars. Ce n'est que récemment que les périodes durant lesquelles les incapacités des radars MARSIS et SHARAD ont été corrélées avec les événements d'éjections de masses coronales (EMC) et de particules énergiques solaires (PES). Les mesures de MAVEN des augmentations du flux d'électrons de PES sont consitantes avec les "blackouts" des radars. Ce phénomène a été attribué à une ionisation supplémentaire de l'atmosphère neutre de Mars par les flux accrus d'électrons de PES, causant une augmentation de la densité d'électrons, ce qui attenue le signal radar. Cependant, l'effet de ce phénomène sur les propriétes physiques de l'atmosphère n'a jamais été observé car les instruments utilisés habituellement expérimentaient des "blackouts". Cette étude propose l'utilisation d'occultations radio afin de mesurer les propriétés physiques de l'atmosphère neutre martienne lors des événements EMC et PES car les signaux radio utilisés par cette méthode ne sont pas atténués par l'ionisation supplémentaire. Les deux études de cas de cette recherche suggèrent que les événements ECM/PES sont corrélés avec une diminution de la réfractivité dans la haute atmosphère de Mars causée par une augmentation de la densité d'électrons, elle-même induite par une ionisation supplémentaire due aux électrons PES. Une perturbation atmosphérique est aussi observée durant les événements EMC/PES suggérant d'autant plus une ionisation supplémentaire de cette région. Nos résultats sont cohérents avec les mesures des électrons PES de MAVEN et MEX ainsi qu'avec les "blackouts" de MARSIS et SHARAD. Ceci présente la première analyse globale de tels effets sur les propriétés physiques de l'atmosphère neutre de Mars.

Mars --- Radio occultation --- Mars Express --- Atmosphere --- Ionosphere --- Remote Sensing --- Mars --- Occultation radio --- Mars Express --- Atmosphère --- Ionosphère --- Télédétection --- Physique, chimie, mathématiques & sciences de la terre > Aérospatiale, astronomie & astrophysique

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The search for life beyond our world necessarily involves the search for exoplanets with Earth-like characteristics. The progress of astrophysics now makes it possible to search for po- tentially habitable planets outside the solar system. This is especially achieved by looking for biological signatures in the spectral footprint of planetary atmospheres. This quest is considered to be one of the main objectives of modern astrophysics and exoplanetology.
The scientific community’s interest in exoplanet research has increased in recent years, par- ticularly in direct observation techniques, such as nulling interferometry, which allows exoplan- ets to be detected and resolved directly from their host star. After failing to develop large-scale space-based interferometry missions in the early 2000s, the first task would be to prove the feasibility of this technique in space. This thesis focuses on a Small Sat platform that could achieve this objective of a technological demonstrator. Besides, the mission also has a scientific objective which is to observe the 5 nearest stellar systems that host exoplanets.
This paper focuses on the observation strategy of the proposed platform and in particular on the observation possibilities provided by several orbits. Simulations are carried out for a whole year and the visibility performance of each orbit is studied. These analyses will allow an optimal design mission by maximizing the use of the platform by avoiding as much as possible the occultation times of the targeted stars.

observation strategy --- space-based interferometry --- Small Sat --- orbit design --- exoplanet. --- occultation --- Ingénierie, informatique & technologie > Ingénierie aérospatiale

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The book is devoted to radio occultation (RO) remote sensing of the earth’s atmosphere and ionosphere as a global method of monitoring. This technique used the radio links satellite-to-satellite when a satellite-receiver setting or rising behind the earth’s atmosphere is relative to a satellite - emitter of radio waves. During setting the radio ray perigee moves through the ionosphere and ionosphere. Atmospheric and ionospheric effects arise in most cases owing to influence of a zone near the radio ray perigee and cause significant variations of the amplitude, phase, and frequency of the radio waves. These variations enable determination of the altitude profiles of temperature, pressure, refractivity, density, humidity and turbulence in the atmosphere, distribution of the electron density in the ionosphere, and the wave phenomena at different altitudes with a global coverage. The aim of this book consists of the systematic description of the different approaches, results of investigation and perspectives of the RO remote sensing as a tool for investigations of the atmosphere and ionosphere.

Atmospheric radio refractivity. --- Ionosphere. --- Ionosphere --- Heaviside layer --- Kennelly-Heaviside layer --- Upper atmosphere --- Radio refractivity, Atmospheric --- Radio refractivity of earth's atmosphere --- Refractivity, Atmospheric radio --- Radio astronomy --- Radio meteorology --- Refractive index --- Physical Sciences --- Engineering and Technology --- Earth and Planetary Sciences --- Atmospheric Sciences --- Atmospheric Radio Occultation

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In the Earth sciences, a transition is currently occurring in multiple fields towards an integrated Earth system approach, with applications including numerical weather prediction, hydrological forecasting, climate impact studies, ocean dynamics estimation and monitoring, and carbon cycle monitoring. These approaches rely on coupled modeling techniques using Earth system models that account for an increased level of complexity of the processes and interactions between atmosphere, ocean, sea ice, and terrestrial surfaces. A crucial component of Earth system approaches is the development of coupled data assimilation of satellite observations to ensure consistent initialization at the interface between the different subsystems. Going towards strongly coupled data assimilation involving all Earth system components is a subject of active research. A lot of progress is being made in the ocean–atmosphere domain, but also over land. As atmospheric models now tend to address subkilometric scales, assimilating high spatial resolution satellite data in the land surface models used in atmospheric models is critical. This evolution is also challenging for hydrological modeling. This book gathers papers reporting research on various aspects of coupled data assimilation in Earth system models. It includes contributions presenting recent progress in ocean–atmosphere, land–atmosphere, and soil–vegetation data assimilation.

land data assimilation system --- land data assimilation --- rainfall-runoff simulation --- 4D-Var data assimilation --- total water storage --- accuracy --- ocean–atmosphere assimilation --- precipitation --- Earth system models --- numerical weather prediction --- fluorescence --- GRACE --- MCA analysis --- weakly coupled data assimilation --- GPM IMERG --- atmospheric models --- rainfall correction --- remote sensing --- microwave remote sensing --- SMAP --- land surface modeling --- bending angle --- floods soil moisture --- vegetation --- GPSRO --- WRF --- merged CMORPH --- land surface model --- temperature --- 4D-Var --- data assimilation --- data-driven methods --- GSI --- radio occultation data --- rainfall --- soil moisture --- sea level anomaly --- total cloud cover --- land surface models --- Mediterranean basin --- interpolation --- sea surface height --- drought --- TRMM 3B42 --- analog data assimilation --- ocean models

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Following the Islamic Revolution of 1979 and the re-introduction of Sharica law relating to gender and the family, women's rights in Iran suffered a major setback. However, as the implementers of the law have faced the social realities of women's lives and aspirations, positive changes have gradually come about. Here Ziba Mir-Hosseini takes us to the heart of the growing debates concerning the ways in which justice for women should be achieved. Through a series of lively interviews with clerics in the Iranian religious center of Qom, she seeks to understand the varying notions of gender that inform Islamic jurisprudence and to explore how clerics today perpetuate and modify these notions.Mir-Hosseini finds three main approaches to the issue: insistence on "traditional" patriarchal interpretations based on "complementarity" but "inequality" between women and men; attempts to introduce "balance" into traditional interpretations; or a radical rethinking of the jurisprudential constructions of gender. She introduces the debates among the commentators by examining key passages in both written and oral texts and by narrating her meetings and discussions with the authors. Unique in its approach and its subject matter, the book relates Mir-Hosseini's engagement, as a Muslim woman and a social anthropologist educated and working in the West, with Shii'i Muslim thinkers of various backgrounds and views. In the literature on women in Islam, there is no account of such a face-to-face encounter, either between religion and gender politics or between the two genders.

Women's rights --- Women in Islam --- Muslim women --- Women --- Shīʻah --- Shi`ah --- Religious aspects --- Islam. --- Doctrines. --- Doctrines --- Iran. --- Afshar, Haleh. --- Akuchakian, Ahmad. --- Borujerdi, ayatollah. --- Doubt (shobheh). --- Dynamic Jurisprudence. --- Ebadi, Shireen. --- Family Protection Law. --- Farzaneh (magazine). --- Hassan, Riffat. --- Imamate. --- Javadi-Amoli, ayatollah. --- Kar, Mehrangiz. --- Khomeini, ayatollah. --- Kiyan (magazine). --- Majles (Parliament). --- Mernissi, Fatima. --- Mottahedeh, Roy. --- Occultation. --- Resalat (daily newspaper). --- Society for Houzeh Teachers. --- Sorush, Abdolkarim. --- Traditional Jurisprudence. --- Wadud-Muhsin, Amina. --- Women’s Day. --- Women’s Week. --- Zan (daily newspaper). --- Zan-e Ruz (magazine). --- Zanan (magazine). --- abortion. --- artificial insemination. --- contraception. --- dower (mahr, mehriyeh). --- ejtehad. --- feminism, feminist views. --- hejab. --- journals, newspapers. --- khadem. --- khoms. --- maintenance. --- mojtahed. --- penal law, women in. --- polygamy (polygyny). --- puberty, age of. --- seyyed. --- taqiyeh. --- treatise. --- velayat-e faqih.