Comparative study of the equatorial ionosphere over Jicamarca during recent two solar minima

	Comparative study of the equatorial ionosphere over Jicamarca during recent two solar minima
	Liu, Libo; Yang, Jun; Le, Huijun; Chen, Yiding; Wan, Weixing; Lee, Chien-Chih
刊名	JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
	2012
卷号	117 页码:A01315
ISSN号	2169-9380
通讯作者	Liu, LB (reprint author), Chinese Acad Sci, Inst Geol & Geophys, Beijing Natl Observ Space Environm, Beijing 100029, Peoples R China.
中文摘要	It is a critical issue that whether or not the extremely deep solar minimum of solar cycle 23/24 brought serious influences on the Earth's space environment. In this study, we collected and manually scaled the ionograms recorded by a DPS ionosonde at Jicamarca (12.0 degrees S, 283.2 degrees E) to retrieve F layer parameters and electron density (N-e) profiles. A comparative study is performed to evaluate the equatorial ionosphere in solar minima of cycle 22/23 (1996-1997) and 23/24 (2008-2009). The seasonal median values of the critical frequency of F-2 layer (f(o)F(2)) were remarkably reduced in four seasons during the deep solar minimum, compared to those in 1996-1997. It is the first time to find that lower values prevail at most times in 2008-2009 in the F2 layer peak height (h(m)F(2)) and Chapman scale height (H-m). The bottomside profile thickness (B0) shows higher values in 2008-2009 than that in 1996-1997 at some daytime intervals, although it also becomes smaller during the rest times. Furthermore, the ionosphere in 2008-2009 is contracted strongly at altitudes above h(m)F(2) and more perceptible in the afternoon hours. The decrease in N-e is strongest in September equinox and weakest in June solstice. The ionospheric responses from solar minimum to minimum are mainly caused by the reduction in solar extreme ultraviolet intensity, and the contribution from dynamical processes competes and is variable. Analysis reveals that semiannual and longer-scale components are certainly reduced during the deep solar minimum, while shorter scale (e. g., 4 month) components may disrupt the decline picture at some times.
英文摘要	It is a critical issue that whether or not the extremely deep solar minimum of solar cycle 23/24 brought serious influences on the Earth's space environment. In this study, we collected and manually scaled the ionograms recorded by a DPS ionosonde at Jicamarca (12.0 degrees S, 283.2 degrees E) to retrieve F layer parameters and electron density (N-e) profiles. A comparative study is performed to evaluate the equatorial ionosphere in solar minima of cycle 22/23 (1996-1997) and 23/24 (2008-2009). The seasonal median values of the critical frequency of F-2 layer (f(o)F(2)) were remarkably reduced in four seasons during the deep solar minimum, compared to those in 1996-1997. It is the first time to find that lower values prevail at most times in 2008-2009 in the F2 layer peak height (h(m)F(2)) and Chapman scale height (H-m). The bottomside profile thickness (B0) shows higher values in 2008-2009 than that in 1996-1997 at some daytime intervals, although it also becomes smaller during the rest times. Furthermore, the ionosphere in 2008-2009 is contracted strongly at altitudes above h(m)F(2) and more perceptible in the afternoon hours. The decrease in N-e is strongest in September equinox and weakest in June solstice. The ionospheric responses from solar minimum to minimum are mainly caused by the reduction in solar extreme ultraviolet intensity, and the contribution from dynamical processes competes and is variable. Analysis reveals that semiannual and longer-scale components are certainly reduced during the deep solar minimum, while shorter scale (e. g., 4 month) components may disrupt the decline picture at some times.
学科主题	空间物理
收录类别	SCI
资助信息	National Natural Science Foundation of China [41074112, 41174137, 40725014]; National Key Basic Research Program of China [2012CB825604]; Specialized Research Fund for State Key Laboratories
语种	英语
公开日期	2014-12-15
内容类型	期刊论文
源URL	[http://ir.nssc.ac.cn/handle/122/3208]
专题	国家空间科学中心_空间科学部
推荐引用方式 GB/T 7714	Liu, Libo,Yang, Jun,Le, Huijun,et al. Comparative study of the equatorial ionosphere over Jicamarca during recent two solar minima[J]. JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS,2012,117:A01315.
APA	Liu, Libo,Yang, Jun,Le, Huijun,Chen, Yiding,Wan, Weixing,&Lee, Chien-Chih.(2012).Comparative study of the equatorial ionosphere over Jicamarca during recent two solar minima.JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS,117,A01315.
MLA	Liu, Libo,et al."Comparative study of the equatorial ionosphere over Jicamarca during recent two solar minima".JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS 117(2012):A01315.