Decaying equatorial F region plasma depletions

被引:21
作者
Hysell, DL [1 ]
Kelley, MC [1 ]
机构
[1] CORNELL UNIV,SCH ELECT ENGN,ITHACA,NY 14853
来源
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS | 1997年 / 102卷 / A9期
关键词
COLLISIONAL INTERCHANGE INSTABILITY; SPREAD-F; NUMERICAL SIMULATIONS; SCALE IRREGULARITIES; STEEPENED STRUCTURES; IONOSPHERE;
D O I
10.1029/97JA01725
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We analyze plasma density data from the AE-E satellite to determine bow F region irregularities decay. This satellite had a low inclination orbit that was ultimately circular at an altitude of 434 km. It frequently observed plasma depletions in the postsunset regime during spread F conditions,sometimes along a trajectory affording a ''horizontal cut'' perspective through the field-aligned irregularities. On one occasion, the satellite passed through nearly the same region of depleted flux tubes on sequential orbits. Data from these orbits imply that the irregularities decay at a constant rate over a broad range of horizontal scale sizes. We introduce a statistical model of the intermediate-scale (10 km - 100 m) plasma irregularities and use it to infer a value for the perpendicular ambipolar diffusion coefficient from the measured decay rate. The value we estimate (2 m(2)/s) is close to the expected classical value. The uniform decay rate and the quasi-universal nature of the intermediate-scale spectra hint that the irregularities themselves maintain a characteristic shape as they decay. High-resolution satellite density measurements show that irregularities have the form of kilometer-scale quasi-periodic depletions. We propose a, one-dimensional, nonlinear model of the collisional interchange instability which admits a closed-form, steady state solution predicting the shape of the depletions. Computer simulations of the model produce kilometer-scale waves that resemble the in situ observations.
引用
收藏
页码:20007 / 20017
页数:11
相关论文
共 19 条
[1]   MOTION OF DEPLETED PLASMA REGIONS IN THE EQUATORIAL IONOSPHERE [J].
ANDERSON, DN ;
HAERENDEL, G .
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 1979, 84 (NA8) :4251-4256
[2]   COEXISTENCE OF KILOMETER-SCALE AND METER-SCALE IRREGULARITIES IN NIGHTTIME EQUATORIAL F-REGION [J].
BASU, S ;
BASU, S ;
AARONS, J ;
MCCLURE, JP ;
COUSINS, MD .
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 1978, 83 (NA9) :4219-4226
[3]  
BURKE WJ, 1978, PLANET SPACE SCI, V27, P593
[4]  
FREDRICKS RW, 1976, J GEOPHYS RES, V31, P5591
[5]  
Hanson W. B., 1975, Space Science Instrumentation, V1, P493
[6]   RETARDING-POTENTIAL ANALYZER ON ATMOSPHERE EXPLORER [J].
HANSON, WB ;
ZUCCARO, DR ;
LIPPINCOTT, CR ;
SANATANI, S .
RADIO SCIENCE, 1973, 8 (04) :333-339
[7]   STEEPENED STRUCTURES IN EQUATORIAL SPREAD-F .2. THEORY [J].
HYSELL, DL ;
SEYLER, CE ;
KELLEY, MC .
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 1994, 99 (A5) :8841-8850
[8]   STEEPENED STRUCTURES IN EQUATORIAL SPREAD-F .1. NEW OBSERVATIONS [J].
HYSELL, DL ;
KELLEY, MC ;
SWARTZ, WE ;
PFAFF, RF ;
SWENSON, CM .
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 1994, 99 (A5) :8827-8840
[9]  
Kelley M.C., 1989, EARTHS IONOSPHERE
[10]   COLLISIONAL INTERCHANGE INSTABILITY .2. A COMPARISON OF THE NUMERICAL SIMULATIONS WITH THE INSITU EXPERIMENTAL-DATA [J].
KELLEY, MC ;
SEYLER, CE ;
ZARGHAM, S .
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 1987, 92 (A9) :10089-10094