New remarks on the magnetic-field regime in the distant geomagnetic tail: Pioneer 8

Summary The emerging overview of the distant tail suggests to interpret some aspects of the magnetic-field observations obtained during January 1968 by Pioneer 8 in the region of expected tail (∼500R _E) in terms of different magnetic-field regimes which might find correspondence in the experimental observations performed at ∼240R _E by ISEE-3. At Pioneer position tail-like fields are typically accompanied by significant values of theB _y component while evidence for a wave activity which mostly perturbs the trasversal magnetic-field components is occasionally detected during tail-like encounters. Paper presented at the V Cosmic Physics National Conference, S. Miniato, November 27–30, 1990.