Interplanetary Coronal Mass Ejections from MAVEN Orbital Observations at Mars

Abstract

The measurements from the Mars Atmosphere and Volatile EvolutioN spacecraft, in orbit around Mars, are utilized to investigate interplanetary coronal mass ejections (ICMEs) near 1.52 au. We identify 24 ICMEs from 2014 December 6 to 2019 February 21. The ICME list is used to examine the statistical properties of ICMEs. On average, the magnetic field strength of 5.99 nT in ICMEs is higher than that of 5.38 nT for stream interaction regions (SIRs). The density of 5.27 cm−3 for ICMEs is quite comparable to that of 5.17 cm−3 for SIRs, the velocity of 394.7 km s−1 for ICMEs is slightly lower than that of 432.8 km s−1 for SIRs, and the corresponding dynamic pressure of 1.34 nPa for ICMEs is smaller than that of 1.50 nPa for SIRs. Using existing databases of ICMEs at 1 au for the same time period, we compare ICME average properties at 1.52 au with those at 1 au. The averages of the characteristic quantities decrease by a factor of 1.1–1.7 from 1 to 1.52 au. In addition, we analyze an unusual space weather event associated with the ICME on 2015 March 9–10, and propose that the extremely strong dynamic pressure with a maximum of ∼18 nPa on March 8 is caused by the combined effects of the enhanced density inside a heliospheric plasma sheet (HPS), the compression of the HPS by the forward shock, and the high velocity of the sheath ahead of the ICME.

Upstream Proton Cyclotron Waves at Mars During the Passage of ICMEs

“…of solar cycle 24 (Zhao et al, 2021). As a result, the distribution of N p V p has a larger median value for the ICME phase compared to the pre-ICME and post-ICME phases (Figure 6c1).…”

“…More recently, Zhao et al. (2021) identified 24 ICMEs using the MAVEN measurements from October 2014 to February 2019, covering the declining phase of solar cycle 24 from a near solar maximum to a near solar minimum condition. Note that these ICMEs generally drive only weak or moderate disturbances at Mars, owing in large part to the general weakness of the solar activity in solar cycle 24.…”

Upstream Solar Wind Prediction up to Mars by an Operational Solar Wind Prediction System

“…(2017) and in Zhao et al. (2021) before 2019. We also removed the other three CMEs‐related data (ICMEs that were identified at 12 April 2019, 21 August 2019, and 4 January 2020).…”

“…For Earth observations, we remove all CMEs-related data by following the manual ICME catalog compiled by Richardson and Cane (2010) (also see http://www.srl.caltech.edu/ACE/ASC/DATA/ level3/icmetable2.htm). For Mars observations, we also remove all CMEs-related data according to the CME catalog in Lee et al (2017) and in Zhao et al (2021) before 2019. We also removed the other three CMEs-related data (ICMEs that were identified at 12 April 2019, 21 August 2019, and 4 January 2020).…”

A Comparison of the Impacts of CMEs and CIRs on the Martian Dayside and Nightside Ionospheric Species

“…In order to select the 15 CME events, we have utilized the catalogs of already identified CME events provided by Zhao et al (2021) and the Space Weather Database of Notifications, Knowledge, and Information (DONKI) (2010) system. Similarly, the 15 CIR events have been selected from the catalogs provided by Geyer et al (2021) and Huang et al (2019) for our analyses.…”