Proton cyclotron waves upstream from Mars: Observations from Mars Global Surveyor

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We present a study on the properties of electromagnetic plasma waves in the region upstream of the Martian bow shock, detected by the magnetometer and electron reflectometer (MAG / ER) onboard the Mars Global Surveyor (MGS) spacecraft during the period known as Science Phasing Orbits (SPO). The freq...

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Autores principales: Romanelli, N., Bertucci, C., Gómez, D., Mazelle, C., Delva, M.
Formato: JOUR
Materias:
Cyclotron
Exosphere
Mars
Pick-up
Upstream
Waves
Bow shocks
Cone angle
Degree of polarization
Electromagnetic plasmas
Elliptical polarization
Interplanetary magnetic fields
Mars global surveyor
Minimum variance analysis
Pick-up ions
Proton cyclotrons
Radial distance
Reference frame
Spatial inhomogeneities
Sub-phase
Theoretical approach
Theoretical result
Time-periods
Wind directions
Cyclotron resonance
Cyclotrons
Electric fields
Electron beams
Ions
Magnetic fields
Pickups
Plasma waves
Polarization
Solar wind
Protons
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00320633_v76_n1_p1_Romanelli
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
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spelling todo:paper_00320633_v76_n1_p1_Romanelli2023-10-03T14:44:45Z Proton cyclotron waves upstream from Mars: Observations from Mars Global Surveyor Romanelli, N. Bertucci, C. Gómez, D. Mazelle, C. Delva, M. Cyclotron Exosphere Mars Pick-up Upstream Waves Bow shocks Cone angle Degree of polarization Electromagnetic plasmas Elliptical polarization Exosphere Interplanetary magnetic fields Mars Mars global surveyor Minimum variance analysis Pick-up ions Proton cyclotrons Radial distance Reference frame Spatial inhomogeneities Sub-phase Theoretical approach Theoretical result Time-periods Upstream Wind directions Cyclotron resonance Cyclotrons Electric fields Electron beams Ions Magnetic fields Pickups Plasma waves Polarization Solar wind Waves Protons We present a study on the properties of electromagnetic plasma waves in the region upstream of the Martian bow shock, detected by the magnetometer and electron reflectometer (MAG / ER) onboard the Mars Global Surveyor (MGS) spacecraft during the period known as Science Phasing Orbits (SPO). The frequency of these waves, measured in the MGS reference frame (SC), is close to the local proton cyclotron frequency. Minimum variance analysis (MVA) shows that these 'proton cyclotron frequency' waves (PCWs) are characterized - in the SC frame - by a left-hand, elliptical polarization and propagate almost parallel to the background magnetic field. They also have a small degree of compressibility and an amplitude that decreases with the increase of the interplanetary magnetic field (IMF) cone angle and radial distance from the planet. The latter result supports the idea that the source of these waves is Mars. In addition, we find that these waves are not associated with the foreshock and their properties (ellipticity, degree of polarization, direction of propagation) do not depend on the IMF cone angle. Empirical evidence and theoretical approaches suggest that most of these observations correspond to the ion-ion right hand (RH) mode originating from the pick-up of ionized exospheric hydrogen. The left-hand (LH) mode might be present in cases where the IMF is almost perpendicular to the Solar Wind direction. PCWs occur in 62% of the time during SPO1 subphase, whereas occurrence drops to 8% during SPO2. Also, SPO1 PCWs preserve their characteristics for longer time periods and have greater degree of polarization and coherence than those in SPO2. We discuss these results in the context of possible changes in the pick-up conditions from SPO1 to SPO2, or steady, spatial inhomogeneities in the wave distribution. The lack of influence from the Solar Wind's convective electric field upon the location of PCWs indicates that, as suggested by recent theoretical results, there is no clear relation between the spatial distribution of PCWs and that of pick-up ions. © 2012 Elsevier Ltd. All rights reserved. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00320633_v76_n1_p1_Romanelli
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Cyclotron
Exosphere
Mars
Pick-up
Upstream
Waves
Bow shocks
Cone angle
Degree of polarization
Electromagnetic plasmas
Elliptical polarization
Exosphere
Interplanetary magnetic fields
Mars
Mars global surveyor
Minimum variance analysis
Pick-up ions
Proton cyclotrons
Radial distance
Reference frame
Spatial inhomogeneities
Sub-phase
Theoretical approach
Theoretical result
Time-periods
Upstream
Wind directions
Cyclotron resonance
Cyclotrons
Electric fields
Electron beams
Ions
Magnetic fields
Pickups
Plasma waves
Polarization
Solar wind
Waves
Protons
spellingShingle Cyclotron
Exosphere
Mars
Pick-up
Upstream
Waves
Bow shocks
Cone angle
Degree of polarization
Electromagnetic plasmas
Elliptical polarization
Exosphere
Interplanetary magnetic fields
Mars
Mars global surveyor
Minimum variance analysis
Pick-up ions
Proton cyclotrons
Radial distance
Reference frame
Spatial inhomogeneities
Sub-phase
Theoretical approach
Theoretical result
Time-periods
Upstream
Wind directions
Cyclotron resonance
Cyclotrons
Electric fields
Electron beams
Ions
Magnetic fields
Pickups
Plasma waves
Polarization
Solar wind
Waves
Protons
Romanelli, N.
Bertucci, C.
Gómez, D.
Mazelle, C.
Delva, M.
Proton cyclotron waves upstream from Mars: Observations from Mars Global Surveyor
topic_facet Cyclotron
Exosphere
Mars
Pick-up
Upstream
Waves
Bow shocks
Cone angle
Degree of polarization
Electromagnetic plasmas
Elliptical polarization
Exosphere
Interplanetary magnetic fields
Mars
Mars global surveyor
Minimum variance analysis
Pick-up ions
Proton cyclotrons
Radial distance
Reference frame
Spatial inhomogeneities
Sub-phase
Theoretical approach
Theoretical result
Time-periods
Upstream
Wind directions
Cyclotron resonance
Cyclotrons
Electric fields
Electron beams
Ions
Magnetic fields
Pickups
Plasma waves
Polarization
Solar wind
Waves
Protons
description We present a study on the properties of electromagnetic plasma waves in the region upstream of the Martian bow shock, detected by the magnetometer and electron reflectometer (MAG / ER) onboard the Mars Global Surveyor (MGS) spacecraft during the period known as Science Phasing Orbits (SPO). The frequency of these waves, measured in the MGS reference frame (SC), is close to the local proton cyclotron frequency. Minimum variance analysis (MVA) shows that these 'proton cyclotron frequency' waves (PCWs) are characterized - in the SC frame - by a left-hand, elliptical polarization and propagate almost parallel to the background magnetic field. They also have a small degree of compressibility and an amplitude that decreases with the increase of the interplanetary magnetic field (IMF) cone angle and radial distance from the planet. The latter result supports the idea that the source of these waves is Mars. In addition, we find that these waves are not associated with the foreshock and their properties (ellipticity, degree of polarization, direction of propagation) do not depend on the IMF cone angle. Empirical evidence and theoretical approaches suggest that most of these observations correspond to the ion-ion right hand (RH) mode originating from the pick-up of ionized exospheric hydrogen. The left-hand (LH) mode might be present in cases where the IMF is almost perpendicular to the Solar Wind direction. PCWs occur in 62% of the time during SPO1 subphase, whereas occurrence drops to 8% during SPO2. Also, SPO1 PCWs preserve their characteristics for longer time periods and have greater degree of polarization and coherence than those in SPO2. We discuss these results in the context of possible changes in the pick-up conditions from SPO1 to SPO2, or steady, spatial inhomogeneities in the wave distribution. The lack of influence from the Solar Wind's convective electric field upon the location of PCWs indicates that, as suggested by recent theoretical results, there is no clear relation between the spatial distribution of PCWs and that of pick-up ions. © 2012 Elsevier Ltd. All rights reserved.
format JOUR
author Romanelli, N.
Bertucci, C.
Gómez, D.
Mazelle, C.
Delva, M.
author_facet Romanelli, N.
Bertucci, C.
Gómez, D.
Mazelle, C.
Delva, M.
author_sort Romanelli, N.
title Proton cyclotron waves upstream from Mars: Observations from Mars Global Surveyor
title_short Proton cyclotron waves upstream from Mars: Observations from Mars Global Surveyor
title_full Proton cyclotron waves upstream from Mars: Observations from Mars Global Surveyor
title_fullStr Proton cyclotron waves upstream from Mars: Observations from Mars Global Surveyor
title_full_unstemmed Proton cyclotron waves upstream from Mars: Observations from Mars Global Surveyor
title_sort proton cyclotron waves upstream from mars: observations from mars global surveyor
url http://hdl.handle.net/20.500.12110/paper_00320633_v76_n1_p1_Romanelli
work_keys_str_mv AT romanellin protoncyclotronwavesupstreamfrommarsobservationsfrommarsglobalsurveyor
AT bertuccic protoncyclotronwavesupstreamfrommarsobservationsfrommarsglobalsurveyor
AT gomezd protoncyclotronwavesupstreamfrommarsobservationsfrommarsglobalsurveyor
AT mazellec protoncyclotronwavesupstreamfrommarsobservationsfrommarsglobalsurveyor
AT delvam protoncyclotronwavesupstreamfrommarsobservationsfrommarsglobalsurveyor
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