Magnetospheric response to the interaction with the sporadic solar wind diamagnetic structure

We report the results of a study on the movement of the solar wind diamagnetic structure (DS), which is a sequence of smaller-scale microDS being part of the May 18, 2013 coronal mass ejection, from a source on the Sun to Earth’s surface. DS determined from the high negative correlation coefficient (r=–0.9) between the IMF modulus (B) and the SW density (N) on the ACE and Wind satellites at the L1 point, on the THB and THC satellites (r=–0.9) in near-Earth orbit, and on the THA satellite inside the magnetosphere is carried by the solar wind from the Sun to Earth’s orbit, while maintaining its fine internal structure. Having a large size in the radial direction (≈763 Rᴇ, where Rᴇ is the Earth radius), DS flows around the magnetosphere. At the same time, microDS of size ≤13 Rᴇ passes through the bow shock and magnetopause as a magnetized plasmoid in which the ion concentration increases from 10 cm⁻³ to 90 cm⁻³, and the velocity decreases as it moves toward the magnetotail. When a microDS passes through the magnetopause, a pulsed electric field of ~400 mV/m is generated with subsequent oscillations with a period of T~200 s and an amplitude of ~50 mV/m. The electric field accelerates charged particles of the radiation belt and produces modulated fluxes of protons in an energy range 95–575 keV on the day side and electrons in 40–475 keV and protons in 95–575 keV on the night side. In the duskside magnetosphere (19–23 MLT), the substorm activation is observed in geomagnetic pulsations and auroras, but without a magnetic negative bay. In the post-midnight sector (01–05 MLT), a sawtooth substorm occurs without the growth phase and breakup with deep modulation of the ionospheric current and auroral absorption. The duration of all phenomena in the magnetosphere and on Earth is determined by the period of interaction between DS and the magnetosphere (~4 hrs). To interpret the regularities of the magnetospheric response to the interaction with DS, we consider alternative models of the impulsive passage of DS from SW to the magnetosphere and the classical model of reconnection of IMF and the geomagnetic field.

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Failure to forecast: A case study in nowcasting and forecasting the eruption of a coronal mass ejection and its geomagnetic impacts on Dec 7-10, 2020.

10.5194/egusphere-egu21-15520 ◽

2021 ◽

Author(s):

Peter Gallagher ◽

Sophie Murray ◽

John Malone-Leigh ◽

Joan Campanyà ◽

Alberto Cañizares ◽

...

Keyword(s):

Magnetic Field ◽

Solar Wind ◽

Solar Flares ◽

Theoretical Models ◽

Western Hemisphere ◽

The Sun ◽

The Earth ◽

Simple Event ◽

Mass Ejection

Forecasting solar flares based on while-light images and photospheric magnetograms of sunspots is notoriously challenging, while accurate forecasting of coronal mass ejections (CME) is still in its infancy. That said, the chances of a CME being launched is more likely following a flare. CMEs launched from the western hemisphere and &#8220;halo&#8221; CMEs are the most likely to be geomagnetically impactful, but forecasting their arrival and impact at Earth depends on how well their velocity is known near the Sun, the solar wind conditions between the Sun and the Earth, the accuracy of theoretical models and on the orientation of the CME magnetic field.&#160; In this presentation, we describe a well observed active region, flare, CME, radio burst and sudden geomagnetic impulse that was observed on December 7-10, 2020 by a slew of instruments (SDO, ACE, DSCOVR, PSP, US and European magnetometers). This was a solar eruption that was not expected, but the CME and resulting geomagnetic impact should have been straight-forward to model and forecast. What can we learn from our failure to forecast this simple event and its impacts at Earth?&#160;

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A review of the SCOSTEP’s 5-year scientific program VarSITI—Variability of the Sun and Its Terrestrial Impact

Progress in Earth and Planetary Science ◽

10.1186/s40645-021-00410-1 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Kazuo Shiokawa ◽

Katya Georgieva

Keyword(s):

Solar Wind ◽

Interplanetary Space ◽

Solar Wind Plasma ◽

The Sun ◽

Scientific Program ◽

Solar Cycles ◽

Grand Minimum ◽

The Earth ◽

Earth Connection ◽

Near Future

AbstractThe Sun is a variable active-dynamo star, emitting radiation in all wavelengths and solar-wind plasma to the interplanetary space. The Earth is immersed in this radiation and solar wind, showing various responses in geospace and atmosphere. This Sun–Earth connection variates in time scales from milli-seconds to millennia and beyond. The solar activity, which has a ~11-year periodicity, is gradually declining in recent three solar cycles, suggesting a possibility of a grand minimum in near future. VarSITI—variability of the Sun and its terrestrial impact—was the 5-year program of the scientific committee on solar-terrestrial physics (SCOSTEP) in 2014–2018, focusing on this variability of the Sun and its consequences on the Earth. This paper reviews some background of SCOSTEP and its past programs, achievements of the 5-year VarSITI program, and remaining outstanding questions after VarSITI.

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3D MHD study of the Earth magnetosphere response during extreme space weather conditions

10.5194/egusphere-egu21-1684 ◽

2021 ◽

Author(s):

Jacobo Varela Rodriguez ◽

Sacha A. Brun ◽

Antoine Strugarek ◽

Victor Réville ◽

Filippo Pantellini ◽

...

Keyword(s):

Solar Wind ◽

Space Weather ◽

Coronal Mass Ejections ◽

Main Sequence ◽

Dynamic Pressure ◽

Weather Conditions ◽

The Sun ◽

Earth Surface ◽

The Earth ◽

The Imf

The aim of the study is to analyze the response of the Earth magnetosphere for various space weather conditions and model the effect of interplanetary coronal mass ejections. The magnetopause stand off distance, open-closed field lines boundary and plasma flows towards the planet surface are investigated. We use the MHD code PLUTO in spherical coordinates to perform a parametric study regarding the dynamic pressure and temperature of the solar wind as well as the interplanetary magnetic field intensity and orientation. The range of the parameters analyzed extends from regular to extreme space weather conditions consistent with coronal mass ejections at the Earth orbit. The direct precipitation of the solar wind on the Earth day side at equatorial latitudes is extremely unlikely even during super coronal mass ejections. For example, the SW precipitation towards the Earth surface for a IMF purely oriented in the Southward direction requires a IMF intensity around 1000 nT and the SW dynamic pressure above 350 nPa, space weather conditions well above super-ICMEs. The analysis is extended to previous stages of the solar evolution considering the rotation tracks from Carolan (2019). The simulations performed indicate an efficient shielding of the Earth surface 1100 Myr after the Sun enters in the main sequence. On the other hand, for early evolution phases along the Sun main sequence once the Sun rotation rate was at least 5 times faster (< 440 Myr), the Earth surface was directly exposed to the solar wind during coronal mass ejections (assuming today&#180;s Earth magnetic field). Regarding the satellites orbiting the Earth, Southward and Ecliptic IMF orientations are particularly adverse for Geosynchronous satellites, partially exposed to the SW if the SW dynamic pressure is 8-14 nPa and the IMF intensity 10 nT. On the other hand, Medium orbit satellites at 20000 km are directly exposed to the SW during Common ICME if the IMF orientation is Southward and during Strong ICME if the IMF orientation is Earth-Sun or Ecliptic. The same way, Medium orbit satellites at 10000 km are directly exposed to the SW if a Super ICME with Southward IMF orientation impacts the Earth.This work was supported by the project 2019-T1/AMB-13648 founded by the Comunidad de Madrid, grants ERC WholeSun, Exoplanets A and PNP. We extend our thanks to CNES for Solar Orbiter, PLATO and Meteo Space science support and to INSU/PNST for their financial support.

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On the Drag parameter of ICME propagation models

10.5194/egusphere-egu2020-21007 ◽

2020 ◽

Author(s):

Gianluca Napoletano ◽

Raffaello Foldes ◽

Dario Del Moro ◽

Francesco Berrilli ◽

Luca Giovannelli ◽

...

Keyword(s):

Solar Wind ◽

Travel Time ◽

Initial Conditions ◽

Solar Wind Speed ◽

Distribution Functions ◽

Model Parameters ◽

Wind Condition ◽

The Sun ◽

The Earth ◽

External Fluid

ICME (Interplanetary Coronal Mass Ejection) are violent phenomena of solar activity that affect the whole heliosphere and the prediction of their impact on different solar system bodies is one of the primary goals of the planetary space weather forecasting. The travel time of an ICME from the Sun to the Earth can be computed through the Drag-Based Model (DBM), which is based on a simple equation of motion for the ICME defining its acceleration as a=-&#915;(v-w)v-w, where a and v are the CME acceleration and speed, w is the ambient solar-wind speed and &#915; is the so-called drag parameter (Vrs&#780;nak et al., 2013). In this framework, &#915; depends on the ICME mass and cross-section, on the solar-wind density and, to a lesser degree, on other parameters. The typical working hypothesis for DBM implies that both &#915; and w are constant far from the Sun. To run the codes, forecasters use empirical input values for &#915; and w, derived by pre-existent knowledge of solar-wind condition and by solving the &#8220;inverted problem&#8221; (where the ICME travel time is known and the unknowns are &#915; and/or w). In the 'Ensemble' approaches (Dumbovich et al., 2018; Napoletano et al. 2018), the uncertainty about the actual values of such inputs are rendered by Probability Distribution Functions (PDFs), accounting for the values variability and our lack of knowledge. Among those PDFs, that of &#915; is poorly defined due to the relatively scarce statistics of recorded values.&#160;Employing a list of past ICME events, for which initial conditions when leaving the Sun and arrival conditions at the Earth are known, we employ a statistical approach to the Drag-Based Model to determine a measure of &#915; and w for each case. This allows to obtain distributions for the model parameters on experimental basis and, more importantly, to test whether different conditions of relative velocity to the solar wind influence the value of the drag efficiency, as it must be expected for solid objects moving into an external fluid. In addition, we perform numerical simulations of a solid ICME-shaped structure moving into the solar-wind modelled as an external fluid. Outcomes from these simulations are compared with our experimental results, and thus employed to interpret them on physical basis.

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Observations of interplanetary scintillation in China

Proceedings of the International Astronomical Union ◽

10.1017/s1743921313002998 ◽

2012 ◽

Vol 8 (S294) ◽

pp. 487-488

Author(s):

Li-Jia Liu ◽

Bo Peng

Keyword(s):

Solar Wind ◽

Interplanetary Medium ◽

Interplanetary Space ◽

Solar Wind Speed ◽

Small Diameter ◽

Primary Source ◽

Radio Sources ◽

The Sun ◽

Interplanetary Scintillation ◽

The Earth

AbstractThe Sun affects the Earth in multiple ways. In particular, the material in interplanetary space comes from coronal expansion in the form of solar wind, which is the primary source of the interplanetary medium. Ground-based Interplanetary Scintillation (IPS) observations are an important and effective method for measuring solar wind speed and the structures of small diameter radio sources. In this paper we will discuss the IPS observations in China.

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Sonification of Astronomical Data

Proceedings of the International Astronomical Union ◽

10.1017/s1743921312000440 ◽

2011 ◽

Vol 7 (S285) ◽

pp. 133-136 ◽

Cited By ~ 5

Author(s):

Wanda L. Diaz-Merced ◽

Robert M. Candey ◽

Nancy Brickhouse ◽

Matthew Schneps ◽

John C. Mannone ◽

...

Keyword(s):

Solar Wind ◽

Time Series Data ◽

Solar Wind Plasma ◽

Series Data ◽

Astronomical Data ◽

X Ray ◽

The Earth ◽

Polar Type ◽

Mass Ejection ◽

The Impact

AbstractThis document presents Java-based software called xSonify that uses a sonification technique (the adaptation of sound to convey information) to promote discovery in astronomical data. The prototype is designed to analyze two-dimensional data, such as time-series data. We demonstrate the utility of the sonification technique with examples applied to X-ray astronomy and solar data. We have identified frequencies in the Chandra X-Ray observations of EX Hya, a cataclysmic variable of the intermediate polar type. In another example we study the impact of a major solar flare, with its associated coronal mass ejection (CME), on the solar wind plasma (in particular the solar wind between the Sun and the Earth), and the Earth's magnetosphere.

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Space Weather

The Sun's Influence on Climate ◽

10.23943/princeton/9780691153834.003.0008 ◽

2015 ◽

Author(s):

Joanna D. Haigh ◽

Peter Cargill

Keyword(s):

Solar Wind ◽

Solar Corona ◽

Space Weather ◽

Coronal Mass Ejections ◽

Interplanetary Medium ◽

Earth Satellite ◽

Satellite Observations ◽

Space Environment ◽

The Sun ◽

The Earth

This chapter focuses on the link between Sun and Earth generically known as space weather. This link is referred to as the occurrence in the solar corona of energetic phenomenon such as flares and coronal mass ejections which can have a major impact on the Earth's space environment. There were other discoveries in subsequent years, but the 1950s and 1960s brought major advances in the understanding of the connection between the Sun and the Earth. Satellite observations confirmed the existence of the solar wind, so that the nature of the interplanetary medium was identified and measured. Such continuous monitoring of the Sun and solar wind has, in turn, led to methods for predicting deleterious space weather.

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Plasma and magnetic field dynamics in the young solar wind

10.5194/egusphere-egu2020-19314 ◽

2020 ◽

Author(s):

Justin Kasper ◽

Keyword(s):

Solar Wind ◽

Angular Momentum ◽

Solar Wind Plasma ◽

Distribution Functions ◽

The Sun ◽

Turbulent Fluctuations ◽

Thermal Distribution ◽

The Earth ◽

Angular Momentum Loss ◽

Coronal Rotation

Parker Solar Probe (PSP) has completed four encounters with the Sun since launch, three with a perihelion of 35.7 solar radii and one at 27.9 solar radii in January of this year.&#160; More than a factor of two closer to the Sun than any previous mission, observations by the spacecraft are already revealing a surprisingly dynamic and non-thermal solar wind plasma near the Sun.&#160; An overview of initial findings related to the solar wind and coronal plasmas will be presented, including the discovery of large-amplitude velocity spikes, highly non-thermal distribution functions, and large non-radial flows of plasma near the Sun observed by the Solar Wind Electrons Alphas and Protons (SWEAP) Investigation plasma instruments and the FIELDS Investigation electromagnetic field instruments.&#160; Once PSP dropped below a quarter of the distance from the Sun to the Earth, SWEAP began to detect a persistent and growing rotational circulation of the plasma around the Sun peaking at 40-50 km/s at perihelion as the Alfv&#233;n mach number fell to 3. &#160;This finding may support theories for enhanced stellar angular momentum loss due to rigid coronal rotation, but the circulation is large, and angular momentum does not appear to be conserved, suggesting that torques still act on the young wind at these distances. &#160;PSP also measured numerous intense and organized Alfv&#233;nic velocity spikes with strong propagating field reversals and large jumps in speed. &#160;These field reversals and jets call for an overhaul in our understanding of the turbulent fluctuations that may, by energizing the solar wind, hold the key to its origin.

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Earth's thermospheric evolution and implications for planetary habitability

10.5194/epsc2020-870 ◽

2020 ◽

Author(s):

Colin Johnstone

Keyword(s):

Carbon Dioxide ◽

Solar Wind ◽

Chemical Composition ◽

Solar System ◽

Planetary Atmospheres ◽

Upper Atmosphere ◽

The Sun ◽

The Earth ◽

First Time ◽

Planetary Habitability

During the Archean eon from 3.8 to 2.5 billion years ago, the Earth's upper atmosphere and interactions with the magnetosphere and the solar wind were likely significantly different to how it is today due to major differences in the chemical composition of the atmosphere and the younger Sun being signifcantly more active. Understanding these factors is important for understanding the evolution of planetary atmospheres within our solar system and beyond. While the higher activity of the Sun would have caused additional heating and expansion of the atmosphere, geochemical measurements show that carbon dioxide was far more abundant during this time and this would have led to significantly thermospheric cooling which would have protected the atmosphere from losses to space. I will present a study of the effects of the carbon dioxide composition and the Sun's activity evolution on the thermosphere and ionosphere of the Archean Earth, studying for the first time the effects of different scenarios for the Sun's activity evolution. I will show the importance of these factors for the exosphere and escape processes of the Earth and terrestrial planets outside our solar system.

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