Mass loss via solar wind and coronal mass ejections during solar cycles 23 and 24

Abstract

Similar to the Sun, other stars shed mass and magnetic flux via ubiquitous quasi-steady wind and episodic stellar coronal mass ejections (CMEs). We investigate the mass loss rate via solar wind and CMEs as a function of solar magnetic variability represented in terms of sunspot number and solar X-ray background luminosity. We estimate the contribution of CMEs to the total solar wind mass flux in the ecliptic and beyond, and its variation over different phases of the solar activity cycles. The study exploits the number of sunspots observed, coronagraphic observations of CMEs near the Sun by SOHO/LASCO, in situ observations of the solar wind at 1 AU by WIND, and GOES X-ray flux during solar cycle 23 and 24. We note that the X-ray background luminosity, occurrence rate of CMEs and ICMEs, solar wind mass flux, and associated mass loss rates from the Sun do not decrease as strongly as the sunspot number from the maximum of solar cycle 23 to the next maximum. Our study confirms a true physical increase in CME activity relative to the sunspot number in cycle 24. We show that the CME occurrence rate and associated mass loss rate can be better predicted by X-ray background luminosity than the sunspot number. The solar wind mass loss rate which is an order of magnitude more than the CME mass loss rate shows no obvious dependency on cyclic variation in sunspot number and solar X-ray background luminosity. These results have implications to the study of solar-type stars.

Radial Sizes and Expansion Behavior of ICMEs in Solar Cycles 23 and 24

“…Petrie (2015) found an increased rate of CMEs from higher latitudes since 2003 (middle of solar cycle 23) due to the weakening of polar photospheric magnetic field which allowed the eruptions from higher latitudes. A similar finding is also reported in Mishra et al (2019). However, some studies suggested that an apparent increase in the CME rate in cycle 24 is due to some artifacts such as cadence and over-counting of narrow and faint ejections in different automated and manual CMEs catalogs (Wang and Colaninno, 2014;Lamy et al, 2017).…”

“…Cycle 24 is found to be weaker than the previous cycle in terms of disturbances that appeared on the solar surface and in the heliosphere (Antia and Basu, 2010;Richardson, 2013). However, several studies have confirmed that the CME rate in solar cycle 24 did not decrease as strongly as the sunspot number from the maximum of cycle 23 to the next maximum (Gopalswamy et al, 2015a;Mishra et al, 2019).…”

The Eroding Disk of AU Mic

“…With a mass per feature of 4×10 −7 M Earth (Chiang & Fung 2017), and loss of three features per decade, the mass-loss rate is 1.2×10 −7 M Earth yr −1 (1.2×10 −13 M e yr −1 ). If the stellar wind mass-loss rate for AU Mic is ∼50×that of the modern Sun (Schüppler et al 2015), the ratio of feature-tostellar-wind mass loss is ∼0.12, similar to the ratio of coronal mass ejection (CME) mass-loss rate to solar wind mass-loss rate (Mishra et al 2019). Analysis of the 2018 HST BAR5 and Transiting Exoplanet Survey Satellite (TESS) data suggests potential sculpting of the disk by a differential stellar wind (Wisniewski et al 2019).…”

Sensitivity of solar wind mass flux to coronal temperature

“…Our results suggest that if there were a way to remotely measure the coronal temperature of the parts of stars in which stellar winds originate, it would be possible to predict the mass loss rate. Unfortunately, only globally integrated observations are available for other stars, which are dominated by closed-loop emission (Cohen 2011; Mishra et al 2019). However, our observations can be used to place new constraints on the mass fluxes predicted by solar and stellar wind models (e.g.…”