Effect of the solar wind conditions on the ionospheric equivalent current systems

	Effect of the solar wind conditions on the ionospheric equivalent current systems
	Zhang, J. J.1,2; Wang, C.1; Tang, B. B.1; Li, H.1
刊名	ANNALES GEOPHYSICAE
	2013
卷号	31 期号:3 页码:489-501
关键词	Ionosphere Electric fields and currents Modeling and forecasting Magnetospheric physics Solar wind-magnetosphere interactions
ISSN号	0992-7689
通讯作者	北京8701信箱
中文摘要	We employ a global magnetohydrodynamics (MHD) model, namely the PPMLR-MHD model, to investigate the effect of the solar wind conditions, such as the interplanetary magnetic field (IMF) clock angle, southward IMF magnitude and solar wind speed, on the average pattern of the ionospheric equivalent current systems (ECS). A new method to derive ECS from the MHD model is proposed and applied, which takes account of the oblique magnetic field line effects. The model results indicate that when the IMF is due northward, the ECS are very weak while the current over polar region is stronger than the lower latitude; when the IMF rotates southward, the two-cell current system dominates, the eastward electrojet on the afternoon sector and the westward electrojet on the dawn sector increase rapidly while the westward electrojet is stronger than the eastward electrojet. Under southward IMF, the intensity of the westward electrojet and eastward electrojet both increase with the increase of the southward IMF magnitude and solar wind speed, and the increase is very sharp for the westward electrojet. Furthermore, we compare the geomagnetic perturbations on the ground represented by the simulated average ECS with the observation-based statistical results under similar solar wind conditions. It is found that the model results generally match with the observations, but the underestimation of the eastward equivalent current on the dusk sector is the main limitation of the present model.
英文摘要	We employ a global magnetohydrodynamics (MHD) model, namely the PPMLR-MHD model, to investigate the effect of the solar wind conditions, such as the interplanetary magnetic field (IMF) clock angle, southward IMF magnitude and solar wind speed, on the average pattern of the ionospheric equivalent current systems (ECS). A new method to derive ECS from the MHD model is proposed and applied, which takes account of the oblique magnetic field line effects. The model results indicate that when the IMF is due northward, the ECS are very weak while the current over polar region is stronger than the lower latitude; when the IMF rotates southward, the two-cell current system dominates, the eastward electrojet on the afternoon sector and the westward electrojet on the dawn sector increase rapidly while the westward electrojet is stronger than the eastward electrojet. Under southward IMF, the intensity of the westward electrojet and eastward electrojet both increase with the increase of the southward IMF magnitude and solar wind speed, and the increase is very sharp for the westward electrojet. Furthermore, we compare the geomagnetic perturbations on the ground represented by the simulated average ECS with the observation-based statistical results under similar solar wind conditions. It is found that the model results generally match with the observations, but the underestimation of the eastward equivalent current on the dusk sector is the main limitation of the present model.
学科主题	空间物理
语种	英语
内容类型	期刊论文
源URL	[http://ir.cssar.ac.cn/handle/122/1543]
专题	国家空间科学中心_空间科学部
作者单位	1.Chinese Acad Sci, Ctr Space Sci & Appl Res, State Key Lab Space Weather, Beijing 100190, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China
推荐引用方式 GB/T 7714	Zhang, J. J.,Wang, C.,Tang, B. B.,et al. Effect of the solar wind conditions on the ionospheric equivalent current systems[J]. ANNALES GEOPHYSICAE,2013,31(3):489-501.
APA	Zhang, J. J.,Wang, C.,Tang, B. B.,&Li, H..(2013).Effect of the solar wind conditions on the ionospheric equivalent current systems.ANNALES GEOPHYSICAE,31(3),489-501.
MLA	Zhang, J. J.,et al."Effect of the solar wind conditions on the ionospheric equivalent current systems".ANNALES GEOPHYSICAE 31.3(2013):489-501.