A comparison of small-scale magnetic fluctuations in the Region 1 and 2 field-aligned current systems

被引：6

作者：

Wu, J. ^{[1
]}

Bryant, M. S. ^{[1
]}

Ridley, C. G. ^{[2
]}

Shen, Y. ^{[1
]}

Yang, L. ^{[3
]}

Clausen, L. B. N. ^{[3
]}

McWilliams, K. A. ^{[2
]}

Murphy, K. R. ^{[4
]}

Mann, I. R. ^{[5
]}

Ozeke, L. G. ^{[5
]}

Korth, H. ^{[6
]}

Anderson, B. J. ^{[6
]}

Waters, C. L. ^{[7
]}

机构：

[1] Univ Calgary, Dept Phys & Astron, Calgary, AB, Canada

[2] Univ Saskatchewan, Inst Space & Atmospher Studies, Saskatoon, SK, Canada

[3] Univ Oslo, Dept Phys, Oslo, Norway

[4] NASA, Goddard Space Flight Ctr, Greenbelt, MD USA

[5] Univ Alberta, Dept Phys, Edmonton, AB, Canada

[6] Johns Hopkins Univ, Appl Phys Lab, Laurel, MD USA

[7] Univ Newcastle, Dept Phys & Math Sci, Callaghan, NSW, Australia

来源：

JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS | 2017年 / 122卷 / 03期

基金：

加拿大自然科学与工程研究理事会; 美国国家科学基金会;

关键词：

Field-aligned current; geomagnetic activity; reconnection; solar wind drivers; substorm; SWARM CONSTELLATION; BIRKELAND CURRENTS; MAGNETOMETER DATA; AURORAL ARCS; MAGNETOSPHERE; CUSP; IONOSPHERE; GENERATION; SATELLITE; CHAMP;

D O I：

10.1002/2016JA023453

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

By determining the location and size of the Region 1 (R1) and Region 2 (R2) large-scale field-aligned currents (FACs) from Active Magnetosphere and Planetary Electrodynamics Response Experiment data, we are able to study the small-scale magnetic fluctuations observed by the Swarm satellites embedded within the large-scale FACs. A statistical comparison of R1 and R2 high-frequency fluctuations is presented in terms of different solar wind conditions and geomagnetic activities. We find that (1) the amplitude of high-frequency fluctuations in both R1 and R2 increases as the large-scale R1 and R2 FACs intensify; (2) high-frequency fluctuations in R1 peak near dayside dawn and dusk, while those in R2 peak around noon; (3) the location of the largest high-frequency fluctuations in R1 shifts in local time in response to IMF B-y, indicating a connection between the R1 fluctuation and the driving solar wind most likely explained by magnetic reconnection; and (4) high-frequency fluctuations in R2 are enhanced in a small region near local noon and respond clearly to nightside drivers, as characterized by the auroral electrojet index. Our analysis shows that the intensity of R1 and R2 high-frequency magnetic fluctuations is directly connected to the intensity of FACs, which implies that the magnetic fluctuations are closely related to the magnetospheric processes that drive them.

引用

页码：3277 / 3290

页数：14

共 39 条

[31] Field-aligned currents associated with Alfven waves in the poleward boundary region of the nightside auroral oval [J].