Clouds Versus Arcs
Location
Yosemite National Park
Start Date
2-8-1974 12:00 PM
End Date
2-8-1974 12:15 PM
Description
Injection of hot particles at synchronous orbit usually occurs several times a day. These injections consist of a sudden appearance of new particles followed by a slow dispersion as they respond to magnetic and electric fields. These particles are slowly lost (presumably by precipitation), but can be easily followed as they drift many times around the earth. Nothing in this data would lead one to suspect the existence of the wide variety of auroral areas occurring simultaneously in the vicinity of the foot of the field line. Comparison of ATS-5 data with all-sky camera pictures shows that plasma injections correspond to the initial brightness of the southernmost arc in a classic substorm. In the present study, additional correlation is made between ATS-5 and photometers on board the NASA Convair 990 by Drs. Eather and Mende. On 11 November 1969, the 990 flew a grid pattern over the nominal foot of the ATS-5 field line. Fortunately, the sky was clear and a mild isolated injection occurred when the spacecraft was near local midnight. Agreement between the plasma injection time and the occurrence of brightening as seen by the photometer is very good. The ratio of intensities of spectral lines also indicates that the photometers are seeing the same particles
Clouds Versus Arcs
Yosemite National Park
Injection of hot particles at synchronous orbit usually occurs several times a day. These injections consist of a sudden appearance of new particles followed by a slow dispersion as they respond to magnetic and electric fields. These particles are slowly lost (presumably by precipitation), but can be easily followed as they drift many times around the earth. Nothing in this data would lead one to suspect the existence of the wide variety of auroral areas occurring simultaneously in the vicinity of the foot of the field line. Comparison of ATS-5 data with all-sky camera pictures shows that plasma injections correspond to the initial brightness of the southernmost arc in a classic substorm. In the present study, additional correlation is made between ATS-5 and photometers on board the NASA Convair 990 by Drs. Eather and Mende. On 11 November 1969, the 990 flew a grid pattern over the nominal foot of the ATS-5 field line. Fortunately, the sky was clear and a mild isolated injection occurred when the spacecraft was near local midnight. Agreement between the plasma injection time and the occurrence of brightening as seen by the photometer is very good. The ratio of intensities of spectral lines also indicates that the photometers are seeing the same particles