Modulation of plasmaspheric hiss intensity by thermal plasma density structure

被引：50

作者：

Chen, Lunjin ^{[1
]}

Thorne, Richard M. ^{[1
]}

Li, Wen ^{[1
]}

Bortnik, Jacob ^{[1
]}

Turner, Drew ^{[2
,3
]}

Angelopoulos, Vassilis ^{[2
,3
]}

机构：

[1] Univ Calif Los Angeles, Dept Atmospher & Ocean Sci, Los Angeles, CA 90024 USA

[2] Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90024 USA

[3] Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90024 USA

来源：

GEOPHYSICAL RESEARCH LETTERS | 2012年 / 39卷

基金：

美国国家科学基金会;

关键词：

DISCRETE CHORUS EMISSIONS; RADIATION BELT ELECTRONS; ORIGIN; THEMIS; MAGNETOSPHERE; INSTRUMENT;

D O I：

10.1029/2012GL052308

中图分类号：

P [天文学、地球科学];

学科分类号：

07 ;

摘要：

Plasmaspheric hiss is an electromagnetic whistler-mode emission confined to high density regions such as the plasmasphere and plasmaspheric plumes. We present a dayside THEMIS event showing that the hiss emission intensity is strongly modulated by thermal plasma density variations. The calculated local growth rate is small (less than 5 dB/R-E) and increases as the plasma density increases, which partly accounts for the modulation. Ray tracing shows that chorus rays, which eventually evolve into plasmaspheric hiss, are focused towards field lines of higher density and defocused away from field lines of lower density. We suggest that the observed modulation is caused by a combined effect of local cyclotron resonant amplification together with ray focusing during propagation.

引用

页数：6

共 31 条

[11] Three-dimensional ray tracing of VLF waves in a magnetospheric environment containing a plasmaspheric plume [J].

Chen, Lunjin ;

Bortnik, Jacob ;

Thorne, Richard M. ;

Horne, Richard B. ;

Jordanova, Vania K. .

GEOPHYSICAL RESEARCH LETTERS, 2009, 36

[12] Propagation of whistler-mode chorus to low altitudes:: divergent ray trajectories and ground accessibility [J].

Chum, J ;

Santolík, O .

ANNALES GEOPHYSICAE, 2005, 23 (12) :3727-3738

[13] ON THE ORIGIN OF PLASMASPHERIC HISS - RAY PATH INTEGRATED AMPLIFICATION [J].

CHURCH, SR ;

THORNE, RM .

JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 1983, 88 (NA10) :7941-7957

[14] MIDLATITUDE AND PLASMASPHERIC HISS - A REVIEW [J].

HAYAKAWA, M ;

SAZHIN, SS .

PLANETARY AND SPACE SCIENCE, 1992, 40 (10) :1325-1338

[15] RAY-TRACING STUDIES AND PATH-INTEGRATED GAINS OF ELF UNDUCTED WHISTLER MODE WAVES IN THE EARTHS MAGNETOSPHERE [J].

HUANG, CY ;

GOERTZ, CK .

JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 1983, 88 (NA8) :6181-6187

[16] First Results of the THEMIS Search Coil Magnetometers [J].

Le Contel, O. ;

Roux, A. ;

Robert, P. ;

Coillot, C. ;

Bouabdellah, A. ;

de la Porte, B. ;

Alison, D. ;

Ruocco, S. ;

Angelopoulos, V. ;

Bromund, K. ;

Chaston, C. C. ;

Cully, C. ;

Auster, H. U. ;

Glassmeier, K. H. ;

Baumjohann, W. ;

Carlson, C. W. ;

McFadden, J. P. ;

Larson, D. .

SPACE SCIENCE REVIEWS, 2008, 141 (1-4) :509-534

[17] Global distributions of suprathermal electrons observed on THEMIS and potential mechanisms for access into the plasmasphere [J].

Li, W. ;

Thorne, R. M. ;

Bortnik, J. ;

Nishimura, Y. ;

Angelopoulos, V. ;

Chen, L. ;

McFadden, J. P. ;

Bonnell, J. W. .

JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 2010, 115

[18] PITCH-ANGLE DIFFUSION OF RADIATION BELT ELECTRONS WITHIN PLASMASPHERE [J].

LYONS, LR ;

THORNE, RM ;

KENNEL, CF .

JOURNAL OF GEOPHYSICAL RESEARCH, 1972, 77 (19) :3455-+

[19] EQUILIBRIUM STRUCTURE OF RADIATION BELT ELECTRONS [J].

LYONS, LR ;

THORNE, RM .

JOURNAL OF GEOPHYSICAL RESEARCH, 1973, 78 (13) :2142-2149

[20] The THEMIS ESA Plasma Instrument and In-flight Calibration [J].

McFadden, J. P. ;

Carlson, C. W. ;

Larson, D. ;

Ludlam, M. ;

Abiad, R. ;

Elliott, B. ;

Turin, P. ;

Marckwordt, M. ;

Angelopoulos, V. .

SPACE SCIENCE REVIEWS, 2008, 141 (1-4) :277-302

← 1 2 3 4 →