First results of the <scp>MAVEN</scp> magnetic field investigation

Connerney, J. E. P.; Espley, J. R.; DiBraccio, G. A.; Gruesbeck, J.; Oliversen, R. J.; Mitchell, David; Halekas, J. S.; Mazelle, C.; Brain, David; Jakosky, B. M.

doi:10.1002/2015gl065366

Cited by 118 publications

(117 citation statements)

References 39 publications

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“…In addition, the orbit precesses around the planet for MAVEN to measure the relevant plasma regimes within the Martian magnetosphere and, because of planetary rotation, to visit all geographic locations. The MAVEN observations shown in this study are from the following instruments: EUVM , SEP , SWIA , and MAG [Connerney et al, 2015a[Connerney et al, , 2015b.…”

Section: Data Used In This Studymentioning

confidence: 99%

MAVEN observations of the solar cycle 24 space weather conditions at Mars

et al. 2017

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The Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft has been continuously observing the variability of solar soft X‐rays and EUV irradiance, monitoring the upstream solar wind and interplanetary magnetic field conditions and measuring the fluxes of solar energetic ions and electrons since its arrival to Mars. In this paper, we provide a comprehensive overview of the space weather events observed during the first ∼1.9 years of the science mission, which includes the description of the solar and heliospheric sources of the space weather activity. To illustrate the variety of upstream conditions observed, we characterize a subset of the event periods by describing the Sun‐to‐Mars details using observations from the MAVEN solar Extreme Ultraviolet Monitor, solar energetic particle (SEP) instrument, Solar Wind Ion Analyzer, and Magnetometer together with solar observations using near‐Earth assets and numerical solar wind simulation results from the Wang‐Sheeley‐Arge‐Enlil model for some global context of the event periods. The subset of events includes an extensive period of intense SEP electron particle fluxes triggered by a series of solar flares and coronal mass ejection (CME) activity in December 2014, the impact by a succession of interplanetary CMEs and their associated SEPs in March 2015, and the passage of a strong corotating interaction region (CIR) and arrival of the CIR shock‐accelerated energetic particles in June 2015. However, in the context of the weaker heliospheric conditions observed throughout solar cycle 24, these events were moderate in comparison to the stronger storms observed previously at Mars.

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Section: Data Used In This Studymentioning

confidence: 99%

MAVEN observations of the solar cycle 24 space weather conditions at Mars

et al. 2017

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“…It makes measurements of ion populations with a cadence of 4 s. The MAG instrument is a fluxgate magnetometer that provides vector magnetic field measurements over a broad range for three axes at a sampling cadence of 32 Hz [ Connerney et al , ]. In the solar wind, the MAG instrument measurement accuracy is 0.15 nT or a few degrees [ Connerney et al , ]. The sampling cadences of SWIA, STATIC, and MAG, as well as their broad measurement ranges, are adequate to resolve low‐frequency waves in the upstream region as demonstrated by Ruhunusiri et al [].…”

Section: Maven Instruments Used For Wave and Plasma Diagnosticsmentioning

confidence: 99%

MAVEN observation of an obliquely propagating low‐frequency wave upstream of Mars

et al. 2016

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We report Mars Atmosphere and Volatile EvolutioN mission observations of a large amplitude low‐frequency plasma wave that propagated oblique to the ambient magnetic field upstream of Mars along with a non‐solar‐wind plasma component that had a flow velocity perpendicular to the magnetic field. We consider nine possibilities for this wave that include various combinations of its propagation direction, polarization in the solar wind frame, and ion source responsible for its generation. Using the observed wave parameters and the measured plasma parameters as constraints, we uniquely identify the wave by systematically discarding these possibilities. We determine that the wave is a right‐hand polarized wave that propagated upstream in the solar wind frame. We find two possibilities for the ion source that can be responsible for this wave generation. They are either newly born pickup protons or reflected solar wind protons from the bow shock. We determine that the observed non‐solar‐wind component is not responsible for the wave generation, and it is likely that the non‐solar‐wind component was merely perturbed by the passage of the wave.

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“…Figure 1 shows the MAVEN/SWIA, MAVEN/MAG, MAVEN/SEP and MSL/RAD measurements during this period including, from top to bottom, the proton temperature (T p ), particle density of alphas (n a ) and protons (n p ), solar wind velocity (v x , v y and v z in Mars-SolarOrbital (MSO) coordinates) and its speed (v), IMF vector components (B x , B y and B z in MSO) and its strength (B), the integrated FTO (three detectors abbreviated as F, T and O) count rate mainly corresponding to protons > 100 MeV through the MAVEN/SEP sensors (more detail in Section 3.1 and also in Larson et al (2015)), and finally the dose rate measured by MSL/RAD on the Martian surface (more detail in Section 3.2 and also shown in Figure 2). Corrections following data processing methods shown in Connerney et al (2015a) have been applied to remove artifacts related to solar array circuit excitation in the MAG data. We also note that the SWIA and MAG data has been selected during each MAVEN orbit taking into account the Martian bow shock structure and the solar wind interactions with Mars ).…”

Section: Data Used In the Analysismentioning

confidence: 99%

Measurements of Forbush decreases at Mars: both by MSL on ground and by MAVEN in orbit

Guo

Lillis

Wimmer‐Schweingruber

et al. 2018

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The Radiation Assessment Detector (RAD), on board Mars Science Laboratory's (MSL) Curiosity rover, has been measuring ground level particle fluxes along with the radiation dose rate at the surface of Mars since August 2012. Similar to neutron monitors at Earth, RAD sees many Forbush decreases (FDs) in the galactic cosmic ray (GCR) induced surface fluxes and dose rates. These FDs are associated with coronal mass ejections (CMEs) and/or stream/corotating interaction regions (SIRs/CIRs). Orbiting above the Martian atmosphere, the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft has also been monitoring space weather conditions at Mars since September 2014. The penetrating particle flux channels in the Solar Energetic Particle (SEP) instrument onboard MAVEN can also be employed to detect FDs. For the first time, we study the statistics and properties of a list of FDs observed in-situ at Mars, seen both on the surface by MSL/RAD and in orbit detected by the MAVEN/SEP instrument. Such a list of FDs can be used for studying interplanetary CME (ICME) propagation and SIR evolution through the inner heliosphere. The magnitudes of different FDs can be well-fitted by a power-law distribution. The systematic difference between the magnitudes of the FDs within and outside the Martian atmosphere may be mostly attributed to the energy-dependent modulation of the GCR particles by both the pass-by ICMEs/SIRs and the Martian atmosphere.

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First results of the MAVEN magnetic field investigation

Cited by 118 publications

References 39 publications

MAVEN observations of the solar cycle 24 space weather conditions at Mars

MAVEN observations of the solar cycle 24 space weather conditions at Mars

MAVEN observation of an obliquely propagating low‐frequency wave upstream of Mars

Measurements of Forbush decreases at Mars: both by MSL on ground and by MAVEN in orbit

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