Highly turbulent environment, the solar wind is a stream of very energetic particles mainly made of protons and electrons. During its trip in the interplanetary space, this solar flow becomes more accelerated during t...Highly turbulent environment, the solar wind is a stream of very energetic particles mainly made of protons and electrons. During its trip in the interplanetary space, this solar flow becomes more accelerated during the outer minima (descending phases) of the solar cycles and can therefore influence all of humanity and its technology. These disturbances lead to socio-economic consequences requiring a precise knowledge of the climate variability. Using a statistical approach, we evaluate the response of the Earth’s magnetosphere to the High-Speed Solar Winds (HSSW) forcing during the peaks of the last five outer minima. To do so, 1UA data of solar wind and magnetic field parameters were extracted from OMNI browser. Analysis of the energetic solar plasma particles shows that strong geomagnetic field variations can occur even in the absence of large solar disturbances. While the normalized reconnection rate was estimated to be ~21% of the total variance of the magnetospheric variables, the upstream of the magnetic cavity was perturbed 80% of the time with large energies recorded. As a result, Earth’s magnetosphere becomes denser (i.e., more drag), which is a problem for spacecraft. Thus, the coupled solar wind-magnetosphere system follows scale-invariant dynamics and is in a state far from equilibrium. Our analysis provides insight into the main cause of geomagnetic storms with more than 97% of HSSW imposed in the range 300 - 850 km/s. These high-speeds lead to auroras that can disrupt electrical and communication systems.展开更多
文摘Highly turbulent environment, the solar wind is a stream of very energetic particles mainly made of protons and electrons. During its trip in the interplanetary space, this solar flow becomes more accelerated during the outer minima (descending phases) of the solar cycles and can therefore influence all of humanity and its technology. These disturbances lead to socio-economic consequences requiring a precise knowledge of the climate variability. Using a statistical approach, we evaluate the response of the Earth’s magnetosphere to the High-Speed Solar Winds (HSSW) forcing during the peaks of the last five outer minima. To do so, 1UA data of solar wind and magnetic field parameters were extracted from OMNI browser. Analysis of the energetic solar plasma particles shows that strong geomagnetic field variations can occur even in the absence of large solar disturbances. While the normalized reconnection rate was estimated to be ~21% of the total variance of the magnetospheric variables, the upstream of the magnetic cavity was perturbed 80% of the time with large energies recorded. As a result, Earth’s magnetosphere becomes denser (i.e., more drag), which is a problem for spacecraft. Thus, the coupled solar wind-magnetosphere system follows scale-invariant dynamics and is in a state far from equilibrium. Our analysis provides insight into the main cause of geomagnetic storms with more than 97% of HSSW imposed in the range 300 - 850 km/s. These high-speeds lead to auroras that can disrupt electrical and communication systems.
