The Experts below are selected from a list of 17406 Experts worldwide ranked by ideXlab platform
Le G Chat - One of the best experts on this subject based on the ideXlab platform.
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on the effect of the Interplanetary medium on nanodust observations by the solar terrestrial relations observatory
arXiv: Solar and Stellar Astrophysics, 2015Co-Authors: Le G Chat, K Issautier, A Zaslavsky, F Pantellini, N Meyervernet, S Belheouane, M MaksimovicAbstract:New measurements using radio and plasma-wave instruments in Interplanetary Space have shown that nanometer-scale dust, or nanodust, is a significant contributor to the total mass in Interplanetary Space. Better measurements of nanodust will allow us to determine where it comes from and the extent to which it interacts with the solar wind. When one of these nanodust grains impacts a Spacecraft, it creates an expanding plasma cloud, which perturbs the photoelectron currents. This leads to a voltage pulse between the Spacecraft body and the antenna. Nanodust has a high charge/mass ratio, and therefore can be accelerated by the Interplanetary magnetic field to speeds up to the speed of the solar wind: significantly faster than the Keplerian orbital speeds of heavier dust. The amplitude of the signal induced by a dust grain grows much more strongly with speed than with mass of the dust particle. As a result, nanodust can produce a strong signal, despite their low mass. The WAVES instruments on the twin Solar TErrestrial RElations Observatory Spacecraft have observed Interplanetary nanodust particles since shortly after their launch in 2006. After describing a new and improved analysis of the last five years of STEREO/WAVES Low Frequency Receiver data, a statistical survey of the nanodust characteristics, namely the rise time of the pulse voltage and the flux of nanodust, is presented. Agreement with previous measurements and Interplanetary dust models is shown. The temporal variations of the nanodust flux are also discussed.
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Interplanetary nanodust detection by the solar terrestrial relations observatory waves low frequency receiver
Solar Physics, 2013Co-Authors: Le G Chat, K Issautier, A Zaslavsky, F Pantellini, N Meyervernet, S Belheouane, M Maksimovic, I ZouganelisAbstract:New measurements using radio and plasma-wave instruments in Interplanetary Space have shown that nanometer-scale dust, or nanodust, is a significant contributor to the total mass in Interplanetary Space. Better measurements of nanodust will allow us to determine where it comes from and the extent to which it interacts with the solar wind. When one of these nanodust grains impacts a Spacecraft, it creates an expanding plasma cloud, which perturbs the photoelectron currents. This leads to a voltage pulse between the Spacecraft body and the antenna. Nanodust has a high charge/mass ratio, and therefore can be accelerated by the Interplanetary magnetic field to the speed of the solar wind: significantly faster than the Keplerian orbital speeds of heavier dust. The amplitude of the signal induced by a dust grain grows much more strongly with speed than with mass of the dust particle. As a result, nanodust can produce a strong signal despite its low mass. The WAVES instruments on the twin Solar TErrestrial RElations Observatory Spacecraft have observed Interplanetary nanodust particles since shortly after their launch in 2006. After describing a new and improved analysis of the last five years of STEREO/WAVES Low Frequency Receiver data, we present a statistical survey of the nanodust characteristics, namely the rise time of the pulse voltage and the flux of nanodust. We show that previous measurements and Interplanetary dust models agree with this survey. The temporal variations of the nanodust flux are also discussed.
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Interplanetary nanodust detection by the solar terrestrial relations observatory waves low frequency receiver
arXiv: Instrumentation and Methods for Astrophysics, 2013Co-Authors: Le G Chat, K Issautier, A Zaslavsky, F Pantellini, N Meyervernet, S Belheouane, M Maksimovic, I ZouganelisAbstract:New measurements using radio and plasma-wave instruments in Interplanetary Space have shown that nanometer-scale dust, or nanodust, is a significant contributor to the total mass in Interplanetary Space. Better measurements of nanodust will allow us to determine where it comes from and the extent to which it interacts with the solar wind. When one of these nanodust grains impacts a Spacecraft, it creates an expanding plasma cloud, which perturbs the photoelectron currents. This leads to a voltage pulse between the Spacecraft body and the antenna. Nanodust has a high charge/mass ratio, and therefore can be accelerated by the Interplanetary magnetic field to speeds up to the speed of the solar wind: significantly faster than the Keplerian orbital speeds of heavier dust. The amplitude of the signal induced by a dust grain grows much more strongly with speed than with mass of the dust particle. As a result, nanodust can produce a strong signal, despite their low mass. The WAVES instruments on the twin Solar TErrestrial RElations Observatory Spacecraft have observed Interplanetary nanodust particles since shortly after their launch in 2006. After describing a new and improved analysis of the last five years of STEREO/WAVES Low Frequency Receiver data, a statistical survey of the nanodust characteristics, namely the rise time of the pulse voltage and the flux of nanodust, is presented. Agreement with previous measurements and Interplanetary dust models is shown. The temporal variations of the nanodust flux are also discussed.
Yuming Wang - One of the best experts on this subject based on the ideXlab platform.
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investigating plasma motion of magnetic clouds at 1 au through a velocity modified cylindrical force free flux rope model
Journal of Geophysical Research, 2015Co-Authors: Yuming Wang, Chenglong Shen, Zhenjun Zhou, Rui Liu, S WangAbstract:Magnetic clouds (MCs) are the Interplanetary counterparts of coronal mass ejections (CMEs), and usually modeled by a flux rope. By assuming the quasi-steady evolution and self-similar expansion, we introduce three types of global motion into a cylindrical force-free flux rope model and developed a new velocity-modified model for MCs. The three types of the global motion are the linear propagating motion away from the Sun, the expanding, and the poloidal motion with respect to the axis of the MC. The model is applied to 72 MCs observed by Wind Spacecraft to investigate the properties of the plasma motion of MCs. First, we find that some MCs had a significant propagation velocity perpendicular to the radial direction, suggesting the direct evidence of the CME's deflected propagation and/or rotation in Interplanetary Space. Second, we confirm the previous results that the expansion speed is correlated with the radial propagation speed and most MCs did not expand self-similarly at 1 AU. In our statistics, about 62%/17% of MCs underwent a underexpansion/overexpansion at 1 AU and the expansion rate is about 0.6 on average. Third, most interestingly, we find that a significant poloidal motion did exist in some MCs. Three speculations about the cause of the poloidal motion are therefore proposed. These findings advance our understanding of the MC's properties at 1 AU and the dynamic evolution of CMEs from the Sun to Interplanetary Space.
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deflected propagation of a coronal mass ejection from the corona to Interplanetary Space
Journal of Geophysical Research, 2014Co-Authors: Yuming Wang, Boyi Wang, Chenglong Shen, Fang Shen, N LugazAbstract:Among various factors affecting the Space weather effects of a coronal mass ejection (CME), its propagation trajectory in the Interplanetary Space is an important one determining whether and when the CME will hit the Earth. Many direct observations have revealed that a CME may not propagate along a straight trajectory in the corona, but whether or not a CME also experiences a deflected propagation in the Interplanetary Space is a question, which has never been fully answered. Here by investigating the propagation process of an isolated CME from the corona to Interplanetary Space during 12-19 September 2008, we present solid evidence that the CME was deflected not only in the corona but also in the Interplanetary Space. The deflection angle in the Interplanetary Space is more than 20. toward the west, resulting a significant change in the probability the CME encounters the Earth. A further modeling and simulation-based analysis suggests that the cause of the deflection in the Interplanetary Space is the interaction between the CME and the solar wind, which is different from that happening in the corona.
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deflected propagation of a coronal mass ejection from the corona to Interplanetary Space
arXiv: Space Physics, 2014Co-Authors: Yuming Wang, Boyi Wang, Chenglong Shen, Fang Shen, N LugazAbstract:Among various factors affecting the Space weather effects of a coronal mass ejection (CME), its propagation trajectory in the Interplanetary Space is an important one determining whether and when the CME will hit the Earth. Many direct observations have revealed that a CME may not propagate along a straight trajectory in the corona, but whether or not a CME also experiences a deflected propagation in the Interplanetary Space is a question, which has never been fully answered. Here by investigating the propagation process of an isolated CME from the corona to Interplanetary Space during 2008 September 12 -- 19, we present solid evidence that the CME was deflected not only in the corona but also in the Interplanetary Space. The deflection angle in the Interplanetary Space is more than 20 degrees toward the west, resulting a significant change in the probability the CME encounters the Earth. A further modeling and simulation-based analysis suggest that the cause of the deflection in the Interplanetary Space is the interaction between the CME and the solar wind, which is different from that happening in the corona.
I Zouganelis - One of the best experts on this subject based on the ideXlab platform.
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Interplanetary nanodust detection by the solar terrestrial relations observatory waves low frequency receiver
Solar Physics, 2013Co-Authors: Le G Chat, K Issautier, A Zaslavsky, F Pantellini, N Meyervernet, S Belheouane, M Maksimovic, I ZouganelisAbstract:New measurements using radio and plasma-wave instruments in Interplanetary Space have shown that nanometer-scale dust, or nanodust, is a significant contributor to the total mass in Interplanetary Space. Better measurements of nanodust will allow us to determine where it comes from and the extent to which it interacts with the solar wind. When one of these nanodust grains impacts a Spacecraft, it creates an expanding plasma cloud, which perturbs the photoelectron currents. This leads to a voltage pulse between the Spacecraft body and the antenna. Nanodust has a high charge/mass ratio, and therefore can be accelerated by the Interplanetary magnetic field to the speed of the solar wind: significantly faster than the Keplerian orbital speeds of heavier dust. The amplitude of the signal induced by a dust grain grows much more strongly with speed than with mass of the dust particle. As a result, nanodust can produce a strong signal despite its low mass. The WAVES instruments on the twin Solar TErrestrial RElations Observatory Spacecraft have observed Interplanetary nanodust particles since shortly after their launch in 2006. After describing a new and improved analysis of the last five years of STEREO/WAVES Low Frequency Receiver data, we present a statistical survey of the nanodust characteristics, namely the rise time of the pulse voltage and the flux of nanodust. We show that previous measurements and Interplanetary dust models agree with this survey. The temporal variations of the nanodust flux are also discussed.
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Interplanetary nanodust detection by the solar terrestrial relations observatory waves low frequency receiver
arXiv: Instrumentation and Methods for Astrophysics, 2013Co-Authors: Le G Chat, K Issautier, A Zaslavsky, F Pantellini, N Meyervernet, S Belheouane, M Maksimovic, I ZouganelisAbstract:New measurements using radio and plasma-wave instruments in Interplanetary Space have shown that nanometer-scale dust, or nanodust, is a significant contributor to the total mass in Interplanetary Space. Better measurements of nanodust will allow us to determine where it comes from and the extent to which it interacts with the solar wind. When one of these nanodust grains impacts a Spacecraft, it creates an expanding plasma cloud, which perturbs the photoelectron currents. This leads to a voltage pulse between the Spacecraft body and the antenna. Nanodust has a high charge/mass ratio, and therefore can be accelerated by the Interplanetary magnetic field to speeds up to the speed of the solar wind: significantly faster than the Keplerian orbital speeds of heavier dust. The amplitude of the signal induced by a dust grain grows much more strongly with speed than with mass of the dust particle. As a result, nanodust can produce a strong signal, despite their low mass. The WAVES instruments on the twin Solar TErrestrial RElations Observatory Spacecraft have observed Interplanetary nanodust particles since shortly after their launch in 2006. After describing a new and improved analysis of the last five years of STEREO/WAVES Low Frequency Receiver data, a statistical survey of the nanodust characteristics, namely the rise time of the pulse voltage and the flux of nanodust, is presented. Agreement with previous measurements and Interplanetary dust models is shown. The temporal variations of the nanodust flux are also discussed.
N Lugaz - One of the best experts on this subject based on the ideXlab platform.
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deflected propagation of a coronal mass ejection from the corona to Interplanetary Space
Journal of Geophysical Research, 2014Co-Authors: Yuming Wang, Boyi Wang, Chenglong Shen, Fang Shen, N LugazAbstract:Among various factors affecting the Space weather effects of a coronal mass ejection (CME), its propagation trajectory in the Interplanetary Space is an important one determining whether and when the CME will hit the Earth. Many direct observations have revealed that a CME may not propagate along a straight trajectory in the corona, but whether or not a CME also experiences a deflected propagation in the Interplanetary Space is a question, which has never been fully answered. Here by investigating the propagation process of an isolated CME from the corona to Interplanetary Space during 12-19 September 2008, we present solid evidence that the CME was deflected not only in the corona but also in the Interplanetary Space. The deflection angle in the Interplanetary Space is more than 20. toward the west, resulting a significant change in the probability the CME encounters the Earth. A further modeling and simulation-based analysis suggests that the cause of the deflection in the Interplanetary Space is the interaction between the CME and the solar wind, which is different from that happening in the corona.
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deflected propagation of a coronal mass ejection from the corona to Interplanetary Space
arXiv: Space Physics, 2014Co-Authors: Yuming Wang, Boyi Wang, Chenglong Shen, Fang Shen, N LugazAbstract:Among various factors affecting the Space weather effects of a coronal mass ejection (CME), its propagation trajectory in the Interplanetary Space is an important one determining whether and when the CME will hit the Earth. Many direct observations have revealed that a CME may not propagate along a straight trajectory in the corona, but whether or not a CME also experiences a deflected propagation in the Interplanetary Space is a question, which has never been fully answered. Here by investigating the propagation process of an isolated CME from the corona to Interplanetary Space during 2008 September 12 -- 19, we present solid evidence that the CME was deflected not only in the corona but also in the Interplanetary Space. The deflection angle in the Interplanetary Space is more than 20 degrees toward the west, resulting a significant change in the probability the CME encounters the Earth. A further modeling and simulation-based analysis suggest that the cause of the deflection in the Interplanetary Space is the interaction between the CME and the solar wind, which is different from that happening in the corona.
Chenglong Shen - One of the best experts on this subject based on the ideXlab platform.
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investigating plasma motion of magnetic clouds at 1 au through a velocity modified cylindrical force free flux rope model
Journal of Geophysical Research, 2015Co-Authors: Yuming Wang, Chenglong Shen, Zhenjun Zhou, Rui Liu, S WangAbstract:Magnetic clouds (MCs) are the Interplanetary counterparts of coronal mass ejections (CMEs), and usually modeled by a flux rope. By assuming the quasi-steady evolution and self-similar expansion, we introduce three types of global motion into a cylindrical force-free flux rope model and developed a new velocity-modified model for MCs. The three types of the global motion are the linear propagating motion away from the Sun, the expanding, and the poloidal motion with respect to the axis of the MC. The model is applied to 72 MCs observed by Wind Spacecraft to investigate the properties of the plasma motion of MCs. First, we find that some MCs had a significant propagation velocity perpendicular to the radial direction, suggesting the direct evidence of the CME's deflected propagation and/or rotation in Interplanetary Space. Second, we confirm the previous results that the expansion speed is correlated with the radial propagation speed and most MCs did not expand self-similarly at 1 AU. In our statistics, about 62%/17% of MCs underwent a underexpansion/overexpansion at 1 AU and the expansion rate is about 0.6 on average. Third, most interestingly, we find that a significant poloidal motion did exist in some MCs. Three speculations about the cause of the poloidal motion are therefore proposed. These findings advance our understanding of the MC's properties at 1 AU and the dynamic evolution of CMEs from the Sun to Interplanetary Space.
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deflected propagation of a coronal mass ejection from the corona to Interplanetary Space
Journal of Geophysical Research, 2014Co-Authors: Yuming Wang, Boyi Wang, Chenglong Shen, Fang Shen, N LugazAbstract:Among various factors affecting the Space weather effects of a coronal mass ejection (CME), its propagation trajectory in the Interplanetary Space is an important one determining whether and when the CME will hit the Earth. Many direct observations have revealed that a CME may not propagate along a straight trajectory in the corona, but whether or not a CME also experiences a deflected propagation in the Interplanetary Space is a question, which has never been fully answered. Here by investigating the propagation process of an isolated CME from the corona to Interplanetary Space during 12-19 September 2008, we present solid evidence that the CME was deflected not only in the corona but also in the Interplanetary Space. The deflection angle in the Interplanetary Space is more than 20. toward the west, resulting a significant change in the probability the CME encounters the Earth. A further modeling and simulation-based analysis suggests that the cause of the deflection in the Interplanetary Space is the interaction between the CME and the solar wind, which is different from that happening in the corona.
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deflected propagation of a coronal mass ejection from the corona to Interplanetary Space
arXiv: Space Physics, 2014Co-Authors: Yuming Wang, Boyi Wang, Chenglong Shen, Fang Shen, N LugazAbstract:Among various factors affecting the Space weather effects of a coronal mass ejection (CME), its propagation trajectory in the Interplanetary Space is an important one determining whether and when the CME will hit the Earth. Many direct observations have revealed that a CME may not propagate along a straight trajectory in the corona, but whether or not a CME also experiences a deflected propagation in the Interplanetary Space is a question, which has never been fully answered. Here by investigating the propagation process of an isolated CME from the corona to Interplanetary Space during 2008 September 12 -- 19, we present solid evidence that the CME was deflected not only in the corona but also in the Interplanetary Space. The deflection angle in the Interplanetary Space is more than 20 degrees toward the west, resulting a significant change in the probability the CME encounters the Earth. A further modeling and simulation-based analysis suggest that the cause of the deflection in the Interplanetary Space is the interaction between the CME and the solar wind, which is different from that happening in the corona.
