Project porcupine : the MF mutual-impedance probe experiment. Part II : Flight F3 and F4 (March 1979)

• Main Authors: Storey, L.R.O., Thiel, J., Illiano, J.M.
• Other Authors: Centre de recherches en physique de l'environnement terrestre et planétaire (CRPE), Centre National de la Recherche Scientifique (CNRS)
• Format: Report
• Language: French
• Published: HAL CCSD 1981
• Subjects: [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; Esrange; Kiruna
• Online Access: https://hal-lara.archives-ouvertes.fr/hal-02191501; https://hal-lara.archives-ouvertes.fr/hal-02191501/document; https://hal-lara.archives-ouvertes.fr/hal-02191501/file/RP_182-60.pdf

This is the second part of a report on the results from the medium-frequency (MF) mutual-impedance probe experiment that was supplied by the Centre for Research in Environmental Physics (CRPE, Orléans, France) as a contribution to the West-German Porcupine program of research on auroral physics during the International Magnetospheric Study. The subject of Part 1 was the results from the first successful flight, named F2, which took place from ESRANGE (Kiruna, Sweden) on 20 March 1977. On that occasion, the MF probe experiment did not succeed in its objective of detecting field-aligned drift motion of the thermal electrons in the auroral ionosphere. The non-reciprocal shift of the lower oblique resonance (L.O.R.) frequency that this motion should have produced was masked by a similar but much larger shift that was obviously spurious, since it varied, more or less sinusoidally, as a function of the spin-phase angle. Various conceivable physical causes for this spurious shift were studied, but were rejected. The question of whether the true cause was some other physical phenomenon, as yet unidentified, or whether it was technological in nature, had to be left open. The results from the flight F2 nevertheless suggested a number of ways in which the experiment could be improved, and these were discussed in Section 5, which concluded Part 1 of the report. In Part 2, after the present preface, Section 7 describes how these and other modifications were made to the MF probe, in preparation for the flights F3 and F4. The changes that were made to some of the other instruments on board are mentioned also. The flight F3 took place on the evening of 19 March 1979, during a quiet interval within a period of repeated auroral activity. A weak negative magnetic bay of about 100 y (K = 2 ) was in progress at the time of launch : see § 7.2. of the report by Haüsler et al. [1982] . The aurora failed to evolve as anticipated, and the payload did not pass through any discrete arc. These relatively calm conditions, which disappointed ...