scholarly journals ICME impact at Earth with low and typical Mach number plasma characteristics

2018 ◽  
Author(s):  
Antti Lakka ◽  
Tuija I. Pulkkinen ◽  
Andrew P. Dimmock ◽  
Emilia Kilpua ◽  
Matti Ala-Lahti ◽  
...  
Keyword(s):  
Solar Wind ◽  
Mach Number ◽  
Strong Dependence ◽  
Space Environment ◽  
Geomagnetic Disturbances ◽  
Interplanetary Coronal Mass Ejection ◽  
Plasma Characteristics ◽  
The Mean ◽  
Mass Ejection ◽  
Global And Local

Abstract. We study how the the Earth's magnetosphere responds to the fluctuating solar wind conditions caused by two different amplitude interplanetary coronal mass ejection (ICME) events by using the Grand Unified Magnetosphere-Ionosphere Coupling Simulation (GUMICS-4). ICME events are known to drive strong geomagnetic disturbances and thus generate conditions that may lead to saturation of the cross-polar cap potential (CPCP). The two ICME events occurred on 15–16 July 2012 and 29–30 April 2014. During the 2012 event, the solar wind upstream values reached up to 35 particles/cm3, speed of 694 km/s, and interplanetary magnetic field of 22 nT. The event of 2014 was a moderate one, with the corresponding upstream values of 30 particles/cm3, 320 km/s and 10 nT. The mean upstream Alfvén Mach number was 2.3 for the 2012 event, while it was 5.8 for the 2014 event. We examine how the Earth's space environment dynamics evolves during both ICME events covering both global and local perspectives. To validate the accuracy of the GUMICS-4 simulation we use satellite data from several missions located in different parts of the magnetosphere. It is shown that the CPCP saturation is affected by the upstream conditions, with strong dependence on the Alfvén Mach number.

scholarly journals GUMICS-4 analysis of interplanetary coronal mass ejection impact on Earth during low and typical Mach number solar winds

2019 ◽  
Vol 37 (4) ◽  
pp. 561-579 ◽  
Author(s):  
Antti Lakka ◽  
Tuija I. Pulkkinen ◽  
Andrew P. Dimmock ◽  
Emilia Kilpua ◽  
Matti Ala-Lahti ◽  
...  
Keyword(s):  
Solar Wind ◽  
Mach Number ◽  
Large Scale ◽  
Space Environment ◽  
Interplanetary Coronal Mass Ejections ◽  
Solar Winds ◽  
Interplanetary Coronal Mass Ejection ◽  
Local Measurements ◽  
Upstream Solar Wind ◽  
Global And Local

Abstract. We study the response of the Earth's magnetosphere to fluctuating solar wind conditions during interplanetary coronal mass ejections (ICMEs) using the Grand Unified Magnetosphere-Ionosphere Coupling Simulation (GUMICS-4). The two ICME events occurred on 15–16 July 2012 and 29–30 April 2014. During the strong 2012 event, the solar wind upstream values reached up to 35 particles cm−3, speeds of up to 694 km s−1, and an interplanetary magnetic field of up to 22 nT, giving a Mach number of 2.3. The 2014 event was a moderate one, with the corresponding upstream values of 30 particles cm−3, 320 km s−1 and 10 nT, indicating a Mach number of 5.8. We examine how the Earth's space environment dynamics evolves during both ICME events from both global and local perspectives, using well-established empirical models and in situ measurements as references. We show that on the large scale, and during moderate driving, the GUMICS-4 results are in good agreement with the reference values. However, the local values, especially during high driving, show more variation: such extreme conditions do not reproduce local measurements made deep inside the magnetosphere. The same appeared to be true when the event was run with another global simulation. The cross-polar cap potential (CPCP) saturation is shown to depend on the Alfvén–Mach number of the upstream solar wind. However, care must be taken in interpreting these results, as the CPCP is also sensitive to the simulation resolution.

scholarly journals Photospheric magnetic field of an eroded-by-solar-wind coronal mass ejection

2016 ◽  
Vol 12 (S327) ◽  
pp. 67-70
Author(s):  
J. Palacios ◽  
C. Cid ◽  
E. Saiz ◽  
A. Guerrero
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Coronal Mass Ejection ◽  
Coronal Hole ◽  
Interplanetary Medium ◽  
Flux Rope ◽  
Magnetic Characteristics ◽  
Interplanetary Coronal Mass Ejection ◽  
Fast Wind ◽  
Mass Ejection

AbstractWe have investigated the case of a coronal mass ejection that was eroded by the fast wind of a coronal hole in the interplanetary medium. When a solar ejection takes place close to a coronal hole, the flux rope magnetic topology of the coronal mass ejection (CME) may become misshapen at 1 AU as a result of the interaction. Detailed analysis of this event reveals erosion of the interplanetary coronal mass ejection (ICME) magnetic field. In this communication, we study the photospheric magnetic roots of the coronal hole and the coronal mass ejection area with HMI/SDO magnetograms to define their magnetic characteristics.

scholarly journals An operational solar wind prediction system transitioning fundamental science to operations

2018 ◽  
Vol 8 ◽  
pp. A39 ◽  
Author(s):  
Jingjing Wang ◽  
Xianzhi Ao ◽  
Yuming Wang ◽  
Chuanbing Wang ◽  
Yanxia Cai ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Arrival Time ◽  
Space Environment ◽  
Maximum Speed ◽  
Source Surface ◽  
Prediction System ◽  
Fundamental Science ◽  
Cone Model ◽  
The Mean

We present in this paper an operational solar wind prediction system. The system is an outcome of the collaborative efforts between scientists in research communities and forecasters at Space Environment Prediction Center (SEPC) in China. This system is mainly composed of three modules: (1) a photospheric magnetic field extrapolation module, along with the Wang-Sheeley-Arge (WSA) empirical method, to obtain the background solar wind speed and the magnetic field strength on the source surface; (2) a modified Hakamada-Akasofu-Fry (HAF) kinematic module for simulating the propagation of solar wind structures in the interplanetary space; and (3) a coronal mass ejection (CME) detection module, which derives CME parameters using the ice-cream cone model based on coronagraph images. By bridging the gap between fundamental science and operational requirements, our system is finally capable of predicting solar wind conditions near Earth, especially the arrival times of the co-rotating interaction regions (CIRs) and CMEs. Our test against historical solar wind data from 2007 to 2016 shows that the hit rate (HR) of the high-speed enhancements (HSEs) is 0.60 and the false alarm rate (FAR) is 0.30. The mean error (ME) and the mean absolute error (MAE) of the maximum speed for the same period are −73.9 km s−1 and 101.2 km s−1, respectively. Meanwhile, the ME and MAE of the arrival time of the maximum speed are 0.15 days and 1.27 days, respectively. There are 25 CMEs simulated and the MAE of the arrival time is 18.0 h.

MHD simulations of magnetospheric response to a strong solar wind density pulse

2021 ◽  
Author(s):  
Andrey Samsonov ◽  
Jennifer A. Carter ◽  
Graziella Branduardi-Raymont ◽  
Steven Sembay
Keyword(s):  
Solar Wind ◽  
Dynamic Pressure ◽  
Solar Wind Density ◽  
Ionospheric Currents ◽  
X Ray ◽  
Interplanetary Coronal Mass Ejection ◽  
Explorer Mission ◽  
The One ◽  
Mass Ejection ◽  
Present Simulation

<p>On 16-17 June 2012, an interplanetary coronal mass ejection with an extremely high solar wind density (~100 cm<sup>-3</sup>) and mostly strong northward (or eastward) interplanetary magnetic field (IMF) interacted with the Earth’s magnetosphere. We have simulated this event using global MHD models. We study the magnetospheric response to two solar wind discontinuities. The first is characterized by a fast drop of the solar wind dynamic pressure resulting in rapid magnetospheric expansion. The second is a northward IMF turning which causes reconfiguration of the magnetospheric-ionospheric currents. We discuss variations of the magnetopause position and locations of the magnetopause reconnection in response to the solar wind variations. In the second part of our presentation, we present simulation results for the forthcoming SMILE (Solar wind Magnetosphere Ionosphere Link Explorer) mission. SMILE is scheduled for launch in 2024. We produce two-dimensional images that derive from the MHD results of the expected X-ray emission as observed by the SMILE Soft X-ray Imager (SXI). We discuss how SMILE observations may help to study events like the one presented in this work.</p>

scholarly journals NEW INSIGHTS INTO SOLAR WIND IMPLANTED VOLATILES FOR LUNAR REGOLITH CHARACTERIZATION: A SIMULATION BASED APPROACH

2018 ◽  
Vol IV-4 ◽  
pp. 199-206
Author(s):  
S. Shukla ◽  
S. Majumdar ◽  
A. Maiti ◽  
S. Kumar
Keyword(s):  
Activation Energy ◽  
Solar Wind ◽  
Frequency Domain ◽  
Particle Density ◽  
Lunar Regolith ◽  
Lunar Soil ◽  
Crystal Defects ◽  
Mining Sites ◽  
Interplanetary Coronal Mass Ejection ◽  
Mass Ejection

<p><strong>Abstract.</strong> The effect of solar wind implanted volatiles into the top 100 nm of the lunar regolith plays a significant role in quantitatively assessing the lunar surface isotopic composition. In essence, these volatiles can either quickly sputter out of the surface or be retained. The implantation processes exhibit a functional dependency on the surface temperature, ilmenite abundance and the activation energy associated with the optical maturity of the lunar soil. The prime focus of this study is to simulate the implication of these incident volatiles in characterizing the regolith for a better insight into the modeling of lunar exosphere during both Interplanetary Coronal Mass Ejection (ICME) and usual cases. Additionally, the proposed model quantifies the total lunar oxygen repository along with determining the associated textural and frequency domain measures for probable future lunar <sup>3</sup>He mining sites. In this 30-day simulation, the particles bombard the reconstructed lunar grid wherein each cell displays varying particle density at a given local time. Moreover, both the activation energy and TiO<sub>2</sub> content are assumed to be in a Gaussian distribution having (&amp;mu;, &amp;sigma;) of (0.96, 0.025) and (12.52, 3.44) respectively. It has been found that the surfaces characterized by high activation energy tend to retain solar wind implants due to the large numbers of crystal defects. However, for H and heavy trace ions, intermediate activation energy range demonstrates diurnal behavior with the diffusive loss at local noon time. The study also finds an intriguing relationship between the lunar O<sub>2</sub> and retained H sites (frequency domain). Furthermore, this could be utilized as a generic exospheric modeling paradigm for airless bodies and contribute to the understanding of the physical processes associated with solar astronomy.</p>

scholarly journals Statistical Analysis of Magnetic Field Fluctuations in Coronal Mass Ejection-Driven Sheath Regions

2021 ◽  
Vol 7 ◽  
Author(s):  
E. K. J. Kilpua ◽  
S. W. Good ◽  
M. Ala-Lahti ◽  
A. Osmane ◽  
D. Fontaine ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Statistical Analysis ◽  
Coronal Mass Ejection ◽  
Inertial Range ◽  
Spectral Indices ◽  
Shock Region ◽  
Field Fluctuations ◽  
The Mean ◽  
Mass Ejection

We report a statistical analysis of magnetic field fluctuations in 79 coronal mass ejection- (CME-) driven sheath regions that were observed in the near-Earth solar wind. Wind high-resolution magnetic field data were used to investigate 2 h regions adjacent to the shock and ejecta leading edge (Near-Shock and Near-LE regions, respectively), and the results were compared with a 2 h region upstream of the shock. The inertial-range spectral indices in the sheaths are found to be mostly steeper than the Kolmogorov −5/3 index and steeper than in the solar wind ahead. We did not find indications of an f−1 spectrum, implying that magnetic fluctuation properties in CME sheaths differ significantly from planetary magnetosheaths and that CME-driven shocks do not reset the solar wind turbulence, as appears to happen downstream of planetary bow shocks. However, our study suggests that new compressible fluctuations are generated in the sheath for a wide variety of shock/upstream conditions. Fluctuation properties particularly differed between the Near-Shock region and the solar wind ahead. A strong positive correlation in the mean magnetic compressibility was found between the upstream and downstream regions, but the compressibility values in the sheaths were similar to those in the slow solar wind (&lt;0.2), regardless of the value in the preceding wind. However, we did not find clear correlations between the inertial-range spectral indices in the sheaths and shock/preceding solar wind properties, nor with the mean normalized fluctuation amplitudes. Correlations were also considerably lower in the Near-LE region than in the Near-Shock region. Intermittency was also considerably higher in the sheath than in the upstream wind according to several proxies, particularly so in the Near-Shock region. Fluctuations in the sheath exhibit larger rotations than upstream, implying the presence of strong current sheets in the sheath that can add to intermittency.

Multi-point observations of a reconnection outflow associated with interacting flux ropes in the solar wind

2020 ◽  
Author(s):  
Zoltan Vörös ◽  
Emiliya Yordanova ◽  
Owen Roberts ◽  
Yasuhito Narita
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Flow Shear ◽  
Magnetic Flux Ropes ◽  
Interplanetary Coronal Mass Ejection ◽  
Flux Ropes ◽  
Magnetic Field Magnitude ◽  
Field Fluctuations ◽  
Mass Ejection ◽  
The Magnetic Field

&lt;p&gt;Twisted magnetic flux ropes embedded in an interplanetary coronal mass ejection (ICME) often contain oppositely oriented magnetic fields and potentially reconnecting current sheets. Reconnection outflows in the solar wind can be identified through magnetic field and plasma signatures, for example, through decreasing magnetic field magnitude, enhanced bulk velocity, temperature and (anti)correlated rotations of the magnetic field and plasma velocity. We investigate a reconnection outflow observed by ACE, WIND and Geotail spacecraft within the interaction region of two flux ropes embedded into an ICME. The SOHO spacecraft, located 15 RE upstream, 120 RE in GSE Y and 5 RE in GSE Z direction from the ACE spacecraft, does not see any plasma signatures of the reconnection outflow. At the same time the other spacecraft, also separated by more than 200 RE in X and Y GSE directions, observe strong plasma and magnetic field fluctuations at the border of the exhaust. &amp;#160;The fluctuations could be associated with Kelvin-Helmholtz (KH) instability at the border of the reconnection outflow with strong flow shear.&amp;#160; It is speculated that the KH instability driven fluctuations and dissipation is responsible for stopping the reconnection outflow which is therefore not seen by SOHO.&lt;/p&gt;

Revisiting the Strongest Martian X-Ray Halo Observed by XMM-Newton on 2003 November 19–21

2020 ◽  
Author(s):  
Limei Yan ◽  
Jiawei Gao ◽  
Lihui Chai ◽  
Lingling Zhao ◽  
Zhaojin Rong ◽  
...  
Keyword(s):  
Solar Wind ◽  
Solar Cycle ◽  
Direct Evidence ◽  
Dynamic Pressure ◽  
Mars Global Surveyor ◽  
Propagation Models ◽  
X Ray ◽  
Interplanetary Coronal Mass Ejection ◽  
Solar Cycle 23 ◽  
Mass Ejection

&lt;p&gt;On 2003 November 20&amp;#8211;21, when the most intense geomagnetic storm during solar cycle 23 was observed at Earth, XMM-Newton recorded the strongest Martian X-ray halo hitherto. The strongest Martian X-ray halo has been suggested to be caused by the unusual solar wind, but no direct evidence has been given in previous studies. Here, based on the Mars Global Surveyor (MGS) observations, unambiguous evidence of unusual solar wind impact during that XMM-Newton observation was found: the whole induced magnetosphere of Mars was highly compressed. The comparison between the solar wind dynamic pressure estimated at Mars from MGS observation and that predicted by different solar wind propagation models suggests that the unusal solar wind is probably related to the interplanetary coronal mass ejection observed at Earth on 2003 November 20.&lt;/p&gt;

scholarly journals An unusual giant spiral arc in the polar cap region during the northward phase of a Coronal Mass Ejection

2007 ◽  
Vol 25 (2) ◽  
pp. 507-517 ◽  
Author(s):  
L. Rosenqvist ◽  
A. Kullen ◽  
S. Buchert
Keyword(s):  
Solar Wind ◽  
Coronal Mass Ejection ◽  
Spiral Structure ◽  
Wind Pressure ◽  
Polar Cap ◽  
Sheath Region ◽  
Interplanetary Coronal Mass Ejection ◽  
Solar Wind Pressure ◽  
Pressure Changes ◽  
Mass Ejection

Abstract. The shock arrival of an Interplanetary Coronal Mass Ejection (ICME) at ~09:50 UT on 22 November 1997 resulted in the development of an intense (Dst<−100 nT) geomagnetic storm at Earth. In the early, quiet phase of the storm, in the sheath region of the ICME, an unusual large spiral structure (diameter of ~1000 km) was observed at very high latitudes by the Polar UVI instrument. The evolution of this structure started as a polewardly displaced auroral bulge which further developed into the spiral structure spreading across a large part of the polar cap. This study attempts to examine the cause of the chain of events that resulted in the giant auroral spiral. During this period the interplanetary magnetic field (IMF) was dominantly northward (Bz>25 nT) with a strong duskward component (By>15 nT) resulting in a highly twisted tail plasma sheet. Geotail was located at the equatorial dawnside magnetotail flank and observed accelerated plasma flows exceeding the solar wind bulk velocity by almost 60%. These flows are observed on the magnetosheath side of the magnetopause and the acceleration mechanism is proposed to be typical for strongly northward IMF. Identified candidates to the cause of the spiral structure include a By induced twisted magnetotail configuration, the development of magnetopause surface waves due to the enhanced pressure related to the accelerated magnetosheath flows aswell as the formation of additional magnetopause deformations due to external solar wind pressure changes. The uniqeness of the event indicate that most probably a combination of the above effects resulted in a very extreme tail topology. However, the data coverage is insufficient to fully investigate the physical mechanism behind the observations.

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