1] The different responses of the magnetosphere to sudden solar wind density enhancements are investigated. The majority of the responses are observed to have two phases: the first is due to an inductive E field propagating through the system, while the second is due to a vortex formation in the magnetosphere. However, during some events, the system displays a single-phase response. In order to understand the controlling parameters in the system response, statistical analyses of several solar wind external characteristics as well as the internal index D st are conducted. Results of these analyses show that none of those characteristics seem to be associated with the way the geospace system responds to the abrupt solar wind density increase. Owing to the lack of statistics in the analysis, simulations investigating the effect of the solar wind Alfvén Mach number on the magnetospheric response have been conducted. The simulation results indicate that the two-phase response is always present but that a low solar wind Mach number causes an indistinct two-phase response, which is difficult to identify as having two phases. Compression signals following the sudden compression at the magnetopause are carried by a fast mode wave in the magnetosphere, which propagates toward the Earth and is reflected back toward the magnetopause by the plasmapause or ionosphere. The wave is subsequently reflected back again, leading to a secondary Earthward propagation. These multiple bounces of the fast mode wave result in two groups of the two-phase responses in the ionosphere, although the second group is extremely difficult to identify in ionospheric data.Citation: Yu, Y.-Q., and A. J. Ridley (2011), Understanding the response of the ionosphere-magnetosphere system to sudden solar wind density increases,
Abstract. We investigate variations of the location and intensity of auroral currents during two magnetic storm periods based on magnetic field measurements from CHAMP separately for both hemispheres, as well as for the dayside and nightside. The corresponding auroral electrojet current densities are on average enhanced by about a factor of 7 compared to the quiet time current strengths. The nightside westward current densities are on average 1.8 (2.2) times larger than the dayside eastward current densities in the Northern (Southern) Hemisphere. Both eastward and westward currents are present during the storm periods with the most intense electrojets appearing during the main phase of the storm, before the ring current maximizes in strength. The eastward and westward electrojet centers can expand to 55 • MLat during intense storms, as is observed on 31 March 2001 with D st =−387 nT. The equatorward shift of auroral currents on the dayside is closely controlled by the southward IMF, while the latitudinal variations on the nightside are better described by the variations of the D st index. However, the equatorward and poleward motion of the nightside auroral currents occur earlier than the D st variations. The Space Weather Modeling Framework (SWMF) can capture the general dynamics of the storm time current variations. Both the model and the actual data show that the currents tend to saturate when the merging electric field is larger than 10 mV/m. However, the exact prediction of the temporal development of the currents is still not satisfactory.
In the present paper we describe the structure of the Chinese health care system and sketch its future development. We analyse issues of provider incentives and the actual burden sharing between government, enterprises and people. We further aim to identify a number of current problems and link these to a discussion of future challenges in the form of an aging population, increased privatization and increased inequity. JEL codes: H51, H75, I11, I18.
We report convection-free anorthite dissolution experiments in a basaltic melt at 1280-7 1500 °C and 0.5 GPa on two different crystallographic surfaces, (12 1) and (302) to investigate 8 dissolution kinetics. The anisotropy of the anorthite dissolution rate along these two surfaces is 9 negligible. Time series experiments at ~1280 °C show that anorthite dissolution is mainly 10 controlled by diffusion in the melt within experimental uncertainty. Analytical solutions were 11 used to model the dissolution and diffusion processes, and to obtain the diffusivities and the 12 saturation concentrations of the equilibrium-determining component (Al 2 O 3) for anorthite 13 dissolution into the basaltic melt. For the first time, we are able to show the physical and 14 chemical characteristics of quench growth effect on the near-interface melt using high spatial 15 resolution (0.3 µm) EDS analyses. For anorthite (An# ≥ 90) saturation in a melt with 39-53 wt% 16 SiO 2 and ≤ 0.4 wt% H 2 O, the concentration of Al 2 O 3 in wt% depends on temperature as follows: 17
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