摘要:

Three sounding rocket measurements of energetic electron precipitation in the 65 to 80 km altitude range above Siple Station, Antarctica suggest a possible diurnal modulation of the precipitation. Flights made on January 10 and 11, 1981, to investigate this possibility showed that no electrons were present after local noon, while a significant flux of penetrating electrons was observed the following day near local dawn, even though the level of magnetic activity was higher during the postnoon flight. A previous flight from Siple Station also observed a large flux of penetrating electrons near local dawn. Calculations of electron drift trajectories in a model magnetic field indicate that moderate values of the convection electric field could cause significant local time variations in the penetrating electron flux at the western edge of the South Atlantic anomaly. These calculations indicate that Siple Station is shadowed by eastern Siberia when it is at local noon, but not when it is at local dawn.

ISSN:0148-0227    

DOI:10.1029/JA090iA01p00548

年代:1985

数据来源: WILEY

摘要:

Measurements of neutral densities, neutral temperature, ion density and ion temperature by the Atmosphere Explorer C and E satellites exhibit fluctuations made up of coherent waves of scale sizes from hundreds to thousands of kilometers. The fluctuations in the AE‐C data are found at times of low magnetic activity to extend from the auroral region in one hemisphere across the equator to the corresponding region in the other hemisphere with little change in apparent wavelength. The fluctuations in the AE‐E data similarly exhibit at times of low magnetic activity nearly uniform wave structure encircling the equatorial belt. Typical examples of 2000 km waves in the AE‐C data and 1500 km waves in the AE‐E data are discussed. To explain these observations, it is suggested that during quiet periods the auroral belts excite quasi‐stationary waves distributed about the earth with coherent periods, possibly tidal, and scale lengths determined by the structure of the belts. According to this interpretation, TID's are manifestations of the transient waves that result from changes in magnetic activity with periods and scale sizes associated with the auroral e

ISSN:0148-0227    

DOI:10.1029/JA090iA01p00553

年代:1985

数据来源: WILEY

ISSN:0148-0227    

DOI:10.1029/JA090iA01p00559

年代:1985

数据来源: WILEY

ISSN:0148-0227    

DOI:10.1029/JA090iA01p00563

年代:1985

数据来源: WILEY

ISSN:0148-0227    

DOI:10.1029/JA090iA01p00565

年代:1985

数据来源: WILEY

ISSN:0148-0227    

DOI:10.1029/JA090iA01p00569

年代:1985

数据来源: WILEY

ISSN:0148-0227    

DOI:10.1029/JA090iA01p00573

年代:1985

数据来源: WILEY

ISSN:0148-0227    

DOI:10.1029/JA090iA01p00574

年代:1985

数据来源: WILEY