Suchergebnisse

Marte es un mundo vasto y complejo. Un planeta rojizo, debido a su superficie, ampliamente cubierta por polvo y rocas de óxido férrico. Marte tiene una atmósfera tenue, principalmente compuesta por dióxido de carbono (CO2), con circulación atmosférica y patrones climáticos, como la Tierra. Sin embargo, tiene destacadas oscilaciones diurnas de viento, debido a una excursión térmica considerable. Las oscilaciones tienen un efecto en todas las capas de la atmósfera, y ejercen una influencia apreciable sobre el resto de la circulación atmosférica global de Marte. En la ultima década, varias misiones han viajado al Planeta Rojo y algunas más han sido aprobadas para ser lanzadas en los próximos años. Dos de estas misiones han sido diseñadas, construidas y operadas por/desde Europa, y son especialmente relevantes para esta Tesis: Mars Express y ExoMars ; Tesis Univ. Granada. ; This work was conducted as part of the project UPWARDS-633127 under the European Union's Horizon 2020 research and innovation Programme. The IAA team was supported by the Spanish Ministry of Economy, Industry and Competitiveness and by FEDER funds under grant ESP2015-65064-C2-1-P (MINECO/FEDER)

López-Valverde, M. A. et al. ; The Martian mesosphere and thermosphere, the region above about 60 km, is not the primary target of the ExoMars 2016 mission but its Trace Gas Orbiter (TGO) can explore it and address many interesting issues, either in-situ during the aerobraking period or remotely during the regular mission. In the aerobraking phase TGO peeks into thermospheric densities and temperatures, in a broad range of latitudes and during a long continuous period. TGO carries two instruments designed for the detection of trace species, NOMAD and ACS, which will use the solar occultation technique. Their regular sounding at the terminator up to very high altitudes in many different molecular bands will represent the first time that an extensive and precise dataset of densities and hopefully temperatures are obtained at those altitudes and local times on Mars. But there are additional capabilities in TGO for studying the upper atmosphere of Mars, and we review them briefly. Our simulations suggest that airglow emissions from the UV to the IR might be observed outside the terminator. If eventually confirmed from orbit, they would supply new information about atmospheric dynamics and variability. However, their optimal exploitation requires a special spacecraft pointing, currently not considered in the regular operations but feasible in our opinion. We discuss the synergy between the TGO instruments, specially the wide spectral range achieved by combining them. We also encourage coordinated operations with other Mars-observing missions capable of supplying simultaneous measurements of its upper atmosphere. © 2018, Springer Science+Business Media B.V., part of Springer Nature. ; The IAA/CSIC team has been supported by the European Union's Horizon 2020 Programme (H2020-Compet-08-2014) under grant agreement UPWARDS-633127, by CSIC Proyecto Intramural 201450E022 and by the Plan Nacional del Espacio ESP2015-65064-C2-1-P (MINECO/FEDER). This research was partly supported by the SCOOP/BRAIN program of the Belgian Science Policy Office (BELSPO). We acknowledge the work of Sabrina Guilbon during her Master internship at LATMOS on the development of the technique to compare the slant profiles of SPICAM and the LMD GCM. M.R.P. thanks UKSA for support under grant ST/I003061/1 and ST/P001262/1. C.F.W. acknowledges funding support from the UK Space Agency. Work by A.K., D.J.MC. and D.M.K. at the Jet Propulsion Laboratory, California Institute of Technology was performed under a contract with the National Aeronautics and Space Administration. OK, NI and AF thanks funding from Roscosmos for the ACS operation support and science funding from The Federal Agency of scientific organization (Planeta No. 0028-2014-0004). ; Peer reviewed

We present a non-local thermodynamic equilibrium retrieval scheme for atmospheric composition and its application to Mars CO2 infrared limb emissions as measured by the OMEGA instrument on board Mars Express (MEx). These emissions are caused by CO2 fluorescence of solar radiation, and thus the retrieval scheme accounts for non-LTE processes. We analyzed the dayside limb observations from a selection of three OMEGA orbits or data qubes. Before the retrieval was applied, we performed a radiometric calibration, cleaned the spectra (including clustering techniques) and generated radiance vertical profiles for each dataset. We also present information on the inversion set up, results on the retrieved CO2 density profiles, as well as the temperature profiles derived from the CO2 densities by assuming hydrostatic equilibrium. An extensive sensitivity study of the retrieval scheme was carried out, including its application to the OMEGA spectra taken at different MEx orbital configurations, to conclude on its performance and to offer recommendations for its systematic use with MEx datasets. The uncertainty due to the instrumental Gain calibration and that caused by the retrieval noise error itself are of large importance for the inversion, but a comparable component of the total error comes from the uncertainties of the temperature provided by the GCM. We demonstrated that, between 120 and 160 km, CO2 profiles can be derived with a precision around 30% and a vertical resolution of about 15 km. © 2020 ; This work was conducted as part of the project UPWARDS-633127 under the European Union's Horizon 2020 research and innovation Programme. The IAA team was supported by grant PGC2018-101836-B-100 ( MCIU/AEI/FEDER, EU ) and by the Spanish MCIU through the 'Center of Excellence Severo Ochoa' award to the IAA/CSIC ( SEV-2017-0709 ). OMEGA data are publicly available via the ESA Planetary Science Archive. ; Peer reviewed